View Full Version : Chatter I-Crib Total Home Control and Automation

09-02-2011, 08:24 PM
I was looking to try as a group to describe what the TOTAL PACKAGE would do.
Make catagories and abilities kind of like.
Security-ability to monitor status of all doors and windows
Smart fridge-knows what you have,what you could make,orders what ever when out(shipped to temp controlled mailbox).
There is much to do and control.Post your ideas here for the Total Package.Try not to get to crazy some things you should still do.

09-02-2011, 08:24 PM
reserved...for compiled list

09-02-2011, 11:41 PM
Speaking as the guy who got a a PING))) for suggesting home automation in the contest thread...

Home automation systems have three elements: sensors, actuators, and control logic. I would like to see Parallax leverage its unique wisdom to do all the things I really wish X10 had.

1. Everything should communicate over power, like X10, but using a less brain-dead protocol. Sure it was nice that X10 burglar alarm sensors didn't need extension cords, but they did need batteries, which got to be a pain, and they never worked very reliably.

2. For protocol simplicity and to avoid data collisions and complicated recovery protocols, I would have all comms initiated by the control logic, even from sensors. Sensors which need to detect events shorter than the polling interval could return a short history. Few things in home automation require true millisecond response.

3. All comms initiated by the controller get a reply, even if it's an actuator saying "got it, boss." If after a fairly short timeout the controller doesn't get a reply, it knows to try again.

Not a lot of modules are needed. I would start with just a few:

1. Relay switched outlet, whose logic can be powered by the outlet it's switching.
2. Relay switched wall switch NOT dimmable, so it can control cheap CFL's, but a bit more tricky because it must be powered in series with the thing it's controlling. Could be a board that goes behind a normal light switch combining the function of reporting the switch position to the controller with digitally controlling the light, so the switch can be overridden. Should revert to manual control if it doesn't hear from the controller for say 5 seconds.
3. After #2, a dimmable switch module. CFL's. But yeah, sometimes you want mood lighting.
4. A module which can be plugged into an outlet and sense and report the state of up to say 8 switches or digital inputs.
5. A temperature sensor. Possibly moddable for generic analog sensor input.
6. A user programmable controller, probably in the form of a C3, protoboard, or Prop Platform shield. Controllers should have the hardware to act as both masters and slaves, to implement other types of sensor and actuator. For example, a keypad/display interface would be useful, but it's not necessary to make a dedicated product; a Prop based controller could read a keyboard, drive a display, and implement comms to the real controller operating as a slave.

The key to making this different from X10 and its extensions/imitators is that all controllers are fully programmable, and while there is default functionality for those who don't want to write a program up-front it's open source and available to download, tweak, extend, and study.

At one time I had a full X10 system controlling most of the lights in my house, several outlets, and a full burglar alarm. I've gradually disassembled it as I moved to light bulbs that don't like the X10 switches, which are all dimmable and incompatible with CFL's, the burglar alarm was prone to false triggers that couldn't be corrected, and all comms were spotty with occasional failures. Offer me a system like I just described, and I will once again replace every light switch in my house.

09-03-2011, 12:17 AM
Nice Roger,I'd love to hear Parallax's think tanks at work on the topic.You made some interesting points as to the mechanics aspect.While communication and power are the backbone to the system.Im not capable of such design skills.Ive seen alot of systems done by alot of companys.There is no do all system available.The many systems need to be compiled together to make big business take thier systems to the next level.What all do we want to control? How?How many ways?securely.A hypothetical Bill Gates home system.What can or could it do?Thats generally where I'd like to discuss.I hope this makes sense.A general scope of the tasks at hand,then the mechanics.

09-03-2011, 12:43 AM
graffix, I think part of the problem was that those closed systems simply couldn't be made to work when a minor tweak to the software might have made them acceptable. I thought of a number of things that might have been done to my burglar alarm to make it more useful and less of a nuisance, but I couldn't do them, nor could I even hire anyone to do so or look for a patch by some like-minded person online, because it was SEALED. If it didn't work for you out of the box, tough.

The main elements of my vision are that sensors and actuators are simple, robust, and comms can be verified, and that controllers are open and reprogrammable. There are a number of ways to manage that. Any of them would be a vast improvement over what's available.

09-03-2011, 03:14 AM
I'd want motorized, self-opening, self-closing, and self-(un)locking doors & windows before I got too deep into home automation.

09-03-2011, 05:18 AM
Roger covered everything that I was going to talk about.

I would also suggest you to look at my project report for the Spinneret contest that I did for the Ship Monitoring and Control System, which is a basic monitoring system that I designed.

My system is based on and similar to building automation systems that I work with at my work. The only thing that my system doesn't do right now is temperature. But, it can networked into the system via RS-485.

Also, take a look at my schematics that I did for my Spinneret contest which would give you a idea how it is interfaced with the propeller and the outside world.

09-03-2011, 07:56 AM
@Local Roger I think off the shelf burglar alarms should be tamper proof so when the wire is cut the alarm still goes off. Locks in general are made for honest people.No home is Fort Knox.If you want in bad enough cut a whole in the wall :)Now just a status indicator of open/closed useful for HVAC settings. Status indicator for locked/unlocked for security. Even at this the mechanics need worked out for new installations and retrofit designs.Possible open source design would be nice.

@erco This is also a good do-able idea, some sort of facial recognition or voice activated type program for exterior doors with a keypad maybe.RFID possible, I saw a system that used a watch awhile ago.Interior doors would be less secure, occupancy locked ability with an overide feature.Perhaps standing in front of the Inside door for a second or two and then open using a PIR maybe.Self opening windows thats new to me,Nice.

As Roger has pointed out almost instant, uniterupted communication will be critcal about every where.Also web interfaced design.On top of that secure design.

@Bsnut I saw your project briefly excellent job BTW, Ive seen some talk on systems using RS-485 protocalls and xbees I think.Without digging in the mechanics of the system (Total Package) what should it do?With all this being said I dont want multiple systems with multiple monthly fee's from different suppiers using stuff that has limited ability or potential. Like Roger said he has gone with X10 system before and would trade it for a better one.Time Warner is getting into also and they bring my internet,cable,and phone.Only thing is Ive had the same cable box for like 12yrs Ive paid off two cars in that time for about the same monthly fee.The Total Package should be every thing (most of which I left out to encourage participation)a fill in the big brain type thread.Granted major manufactures of windows,doors,and appliances will need a base protocall to connect with each other the system and power grid.

We've described some top notch windows and doors at least here.Nothing like whats available currently.The only way to beat or out sell the Total Package would be to One up it,that would be a challenge.How many times have you bought something like a Ipad only a year later have to buy another because they left out a camera or HDMI slot.A car, sure you can have AWD but you lose the sunroof and navigation.These tactics suck.We do it to ourselves based on what we do purchase and pay for.Big business want monthly fees and contracts only to raise the price after your hooked or locked in.

09-03-2011, 12:14 PM
as far as the window ,change the tint or opacity as an alternative to shades-added ability

09-03-2011, 01:03 PM
Radio Shack was handling the Z-Wave systems for a while for home automation. Each remote had a repeater in it so there should be no "blind spots" in the house. Problem was if you wanted to control it by cell phone, it cost $15 a month! I checked into the protocol but $1500 pay to play and non disclosure agreements abounded. Sounded perfect for Spinnernet and the Prop could have brought all sorts of add ons to the party. They even had USB transceivers that you could use to interface,test the RF elements.

Loopy Byteloose
09-03-2011, 04:06 PM
Years ago I got rather deeply into CANbus for a home automation network rather than X10. The advantages are several. The foremost is that you can have the network operate from low voltage battery backup if the A/C power goes out, including an alarm system. After all, any clever burglar might consider just shutting down the A/C to turn off alarms. Cutting an alarm at a sensor would be seen by the CANbus.

Other considerations are about its robustness and its ability of share a network with a lot traffic that has different purposes. CANbus can have multiple masters and slaves sharing wire through its addressing system. It can also use a variety of microconltrollers - Propellers, BasicStamps, PICs, AVRs, and so on. And, CANbus can reacher further (easily up to a mile or so) to monitor outlying buildings or gates and lights out on a large property. It also can be made very difficult to hack into even if one has access to the cable. I have doubts about X10 doing any of these things, but there were some second generation devices that improved on X10 that may be of interest. From what I understand, X10 is always blocked at a distribution transformer and can go no further. And in some cases, X10 might be hacked from a neighboring house that is on the same side of a distribution transformer.

I do like the idea that a low-voltage network means that you can pull something like telephone wire(4 wires/2 twisted pair) or internet LAN cable (which is 8 wires/4 twisted pairs) and have extra wires used to provide power throughout the network. Backup batteries can be placed as critical locations and even solar recharging is possible. You can even have a bridge to LAN (I have a TINI DS80C411 board that does so - included CANbus, IButtons, and LAN with the ability for JAVA to create webpages) and that would provide a destination for keeping info such as an inventory of what's in the refrigerator available.

An often missed fact is that the Propeller can be used with a bar code scan. So having that as a means to inventory groceries is quite an interesting possibility.

Don't forget including hot tub and swimming pool control in your network. And of course, any decorative fountains might be included as well.

09-03-2011, 07:48 PM
If it's to contain alarm systems and other 'secure' functions at all, I would suggest NOT using the AC wiring for it.
(Pulling a pair or even three thin wires in the same plastic conduits shouldn't be a very large problem. They can also be hidden behind fairings and such)

Take a look at the DalSemi 1-Wire protocol, which only uses GND and Signal.
When the controller wants a status, it drops the signal to 0 for a predetermined length of time. Any units that has anything to report will then hold the signal line low for a moment after the controller releases it back to 5V.
Timing this period tells the controller if there's any units requesting a checkup.
(Then there's a messy bit of searching out and communicating with the unit(s) needing it)

Alarms should of course poll everything from time to time, and the communication needs to be encrypted with a random-seeming control 'question' so that a fake unit can't respond instead of a disabled unit.

With more than one 'control' in the system, you need to have priorities and user premissions.
(Kids having one each, but can't switch the PS3 on if the parents have locked it off.... )

Scheduled programs...
This is the more difficult part to get right.
This really needs a 'random' function that can be used to run scripts.

Imagine that one a day you're away, that in the evening TV goes on before the news, stays on for a while, maybe the volume changes when a movie starts? (you must input the movie into the system, of course), then a minute or three(random) after the movie ends, the TV is switched off. Soon after, the ligths in the livingroom goes out, the lights in the bedroom, and moments later, the bathroom goes on. Water runs... Bahroom lights goes out. Roof lamp in bedroom goes out, but a small light stays on for a while(random, with parameters).
Maybe, in the middle of the night(random occurence, at semi-random time) the nightlamp goes on, bathroom lights, minutes later a flush, water running, lights out in bathroom, nightlight following soon after.

Beats the 'random' function on digital timers people use to simulate that someone is home...

09-04-2011, 12:34 AM
The reason for running the signals through power is that the wires are already there, and if you need to run different wires 90% of your potential customers simply won't adopt. Things like security are secondary; the first consideration is to provide a convenient way to control lights and appliances centrally within a home. Everything else is what we in Louisiana call "Lagniappe." It's also worth bearing in mind that a Parallax home control system probably isn't going to be adopted widely enough to tempt hackers, and even X10 was only a real problem because of the ridiculously low number of home codes and the likelihood that you'd collide with a neighbor on your transformer by accident. If it's end user programmable and your neighbor starts messing with your lights you can do something about it that they probably won't have the resources to figure out. With X10, once they knew you had an X10 system if you changed your home code it only took a few minutes to test all the possibilities. The sad thing is you could probably use the X10 signaling protocol to do something 10,000% better, but the cheap solutions were closed and the programmable solutions, like the BASIC stamps that spoke X-10, were expensive and didn't have the built-in high level interfaces.

Control lights and provide user definable remote switches first, so you can turn on the hot tub and lawn lights from the bedroom. Then make it programmable so you can have it happen automatically or stop your neighbor's kid from messing with it if he finds out you have a system. Then start adding geegaws like burglar alarms and environmental controls and so on. Basics first, in a way that is cheap, simple, and flexible. Then, if it catches on, you start adding the prebuilt alarm controllers and thermostats.

Loopy Byteloose
09-04-2011, 01:41 AM
Home automated lighting control can be very problematic as existing switches are distributed all over the home and are at either 110VAC or 220VAC. Where exactly do you expect to install your switching for such? Also, the 'nice' idea of dimming is getting more difficult to do as we shift away from incadescent lights and into flourescent. Mood lighting systems would better be localized, set up with LEDs and powered by PWM.

Regarding the light switch, I feel that the best alternative is what is often used in industrial setting (where there are many more lights which are included on one wall switch). Since the lighting is far more than the 15amps that a light switch can handle, it uses a low voltage latching relay in a central box with a mating low voltage wall switch.

As you can see, that pretty much requires the whole home's lighting to be rewired to have low-voltage switches in the wall and the fuse box have a unit next to it full of latching relays. Of course, if you are building a new custom home, you can elect this from the start and make lighting control much easier. But the really nice thing about this kind of a system is you can get at all the lighting switches in parallel control at one central box with a control voltage that is more suited for microcontroller integration.

X10 may be more handy if they perfect a good light switch that reliably responds to X10 commands and easily fits into the existing light switch box.

About the only other option I could consider is to have an IR transmiter in each room and linked to the network and have IR sensors attached to some sort of relay at each and every light switch. Those light switch electrical boxes are going to get awfully crowded with an IR sensor, a relay of some sort, a power supply, a microcontroller, and a conventional switch.

In sum, automated lighting is best done through planning with a builder before the house is built.

If X10 is going to become widely used, I suspect you want to install an isolation transformer where the service comes into the home.

Nobody is touting fiber optic networking , which would be great for remodle as there is no fire hazard.

09-05-2011, 06:02 AM
Only slightly related but have you seen this new bulb?It was at googleI/O.Supposed to work with android and should be out this year.I saw a price at $40 but I'd wait to see.

09-05-2011, 09:50 AM
I have been an electrician with 23+ years of experience, with the first 3yrs doing custom homes and working for the last 10yrs maintaining, programming, and installing different types of automation systems.

I am going cover X10 first and move on to other of everyone's points.

The way around the X10 problems is to use a isolation transformer, this prevents someone else's House code from interfering with yours. But, the best place for the isolation is to be located just before your main breaker. This means you will need to add in another main disconnecting means to meet the National Electrical Code and needs to be sized for your home. It also saves you from adding another panel. This can be expensive for everyday home owner. You can also add a subpanel with a isolation transformer between your main panel and remove circuits that are not needed to be on the X10 network to this subpanel. But you still need to size it for this subpanel.

Now let me move on to other types of networks that I like.

Canbus is a very reliable network with little or no problems and is used in cars because of the multiple masters and slaves that can be on the network. But, you will need to pull wire to each of the controllers. Unlike X10 which uses the wires you are plugging your lights in. You can also setup subpanel without the isolation transformer as I described above.

Buildings that I maintain for Uncle Sam use multiple types networks for building automation like BACnet, Ethernet, and Fiber. Although are systems are setup for HVAC. But, they can be setup to do other things like you want to do. BACnet is also a cross between RS-485 and Canbus and is designed to be use in buildings and is very reliable.

Somebody stated that it's in the planning and that is correct. This planning begins when the walls are opened up. Because a typical system requires the wire to be pulled from the control device (controller) to the end device (lights, fans, etc). This includes both the low and high voltage wiring. If want you can install a system, by fishing wires in the walls. But, this way is a pain in a butt.

Remember, whatever network protocols you pick. You can setup your system with its own security and control features within the protocol you pick to prevent problems you are talking about.

09-05-2011, 10:37 AM
Of course there is also wireless - the issues of wiring get replaced by battery life. On the plus side the money saved on the wire probably more than covers the cost of wireless modules and you can move things around easily. Also it opens up the garden and yard to networking in (automated watering, weather monitoring, frost warning). A secure protocol is then a requirement of course.

I think one of the key functionalities is detecting human presence - this allows energy saving with heating and lighting, burglar detection, automatic door/window security. Its not easy though.

Another useful feature in my book is tracking utility usage (electricity obviously, but gas, water etc too) - a dashboard interface can then let you simply see where the money is going.

I think RFID is a good technology to add to housekeys - the system knows you haven't picked to lock, can anticipate you next action depending on who and what time of day (TV on in the evening!).

Monitoring exterior and interior temperatures and house occupancy allows Just-in-Time heating control (and if coupled to smoke detectors, an alarm and SMS-sending could act as a personal fire-alarm system).

Finally automatic curtain/blind operation would be great ;)

09-05-2011, 01:43 PM
This is an interesting and useful project.

One thing to watch out for is "function creep". That means don't try to eat the elephant in one bite.
Once the lists of "wants" is big enough, select the most basic, universal items, and concentrate on those. IE communication over power, switching power, and the associated interfaces. Start with the first one, and move on to the next when complete.

Start with the High Level Request; define the systems needed to do this, define the functions the system must perform, and define the code needed to perform those functions. Decide the set of tests that prove the function is present and operates correctly. Do this for each high level request, and do not assume the code can be written before the preceding steps are complete. Code CAN be written for experiments while forming and deciding the preceding steps; this is required; but it cannot be assumed to be the final code. Do this for each high level request in turn.

The caution is against trying to address every ancillary function (wireless, battery issues) before the basic issues (switching, isolation transformers, user interface framework) are established.

The key is to start with a specific functional request, design it, implements it, and test it. After one is complete, you have something to show, and you can start on the next.

Keeping the tasks and results organized is a main factor contributing to success.

09-05-2011, 09:09 PM
What Prof Braino said. He gives the very reasons why I made the more limited suggestion that I did, but explains the rationale better.

Loopy Byteloose
09-06-2011, 10:26 AM
Several aspects have specific barriers to development. Previously I pointed out that lighting actually needs a good replacement for the ubiquitous light switch. From further reading, I have learned that someone makes X10 light switches, but that implies installing an isolation transformer between the meter and the fuse box.

Now, looking at automated lockable windows and doors, I suspect that this is a product line in itself. Latches with appropriate digital control would be much more appealing if they were 'architectural quality', meaning unseen. And both doors and windows have issues with local fire codes as both fire exits and barriers to the spread of flame. In some cases, the latch's normal function must be overridden by the presence of fire.

Again, this all implies are rather extensive remodel or a custom built new home approach. But together with a good lighting scheme, one would be well along the way to a completely automated home.

Other issues, such as heating/cooling and ventilation are rather centralized. Alternatively, bathroom and kitchen environments are rather localized and specific in their demands. Just providing an appropriate bridge onto the home automation network with room enough for expansion would be helpful. Outdoor areas are rather different than indoor - some environmental controls for the building's heating and cooling might be wanted, but in most cases if would be more about perimeter security and ambiance lighting. Wiring could easily be placed underground, so alternatives are more flexible.

09-07-2011, 12:27 AM
The three most important words for a successful popular home automation kit are: no new wiring. X10 got this right, if nothing else.

This leaves two problems. #1 is truly isolated things like burglar alarm sensors and thermostats, which may have no common wiring with the rest of the house. The X10 approach of making these wireless is probably best, but their solution was fickle, easily hacked, and unreliable. Conveniently Parallax owns a CPU design which can be throttled to insanely low levels of power usage, though...

The other problem is light switches, which in nearly all US homes can only receive power in series with their load. X10 does this by assuming a resistive load, but their scheme breaks (and badly) with anything else; I ruined 3 lamp modules trying to power a hot tub lighting system, which started with a transformer to 12VAC, before I realized I needed to use a relay-output appliance module for that. Whatever it is has to work with CFL's. This might require trickling energy into a temporary store such as a supercap to be used when power can't be extracted in series with the load. Or a very small resistance could be in series with the load, equipped with something like a joule thief to power the switch when its load is on.

Later, add-ons might be created to tempt adopters into tackling a wiring job, but if the basic system requires rewiring it will not take off.

Loopy Byteloose
09-07-2011, 07:49 AM
No new wiring?

Obviously, I don't think that is possible. Even X10 suggests an isolation transformer. I fear that one might just have an overlay of extension cords and a clutter of gadgets at electrical outlets. And so I take the more architectural approach.

Low voltage DC wiring presents no fire hazard and in many areas doesn't even require an electrician to install. Also, it can be easily hidden behind specially adapted baseboards (not a big cost) and pulled through vertical stud wall cavities if there is a need to get higher locations. And that is why I mentioned CANbus - electrically safe and able to provide a level of service that is diverse AND secure.

I believe that if solutions are looked for that are well-integrated and have the kind of simple appeal that Apple has become famous for, people will buy and install home automated that does require wiring. Sure, it isn't a DIY after-market, but it is a real market. And may be a lot safer than what people are trying to do with X10 now.

I think I've already made my presentation in several segments - specifically designed light switches (and maybe similar outlets) which allow remote control to override local control; new door and windows systems that have systems built into them and their frames rather than an overlay of latches and sensors; and the rest can pretty much be considered as specialized contexts - kitchens, baths, swimming pools, etc.

At some point, automated home does mean that additions require power. How would you fit a power window to an auto that does not have power windows without additional wiring? Paradoxical to me.

X10 in its current state is convenient for some specific needs, but it would rather clutter up a whole house.

I am aware that the X10 light switches are NOT able to handle any and all kinds of loads at this time, relays need to be deployed somehow and I suspect that means mechanic relays - not solid-state.

As we have seen with Wifi, anything wireless can be snooped. If a wireless scheme is deployed, I'd prefer have it be IR with a hand held remote to be an added feature and each room would be isolated as an area of transmission.

09-07-2011, 09:21 AM
At some point, automated home does mean that additions require power. How would you fit a power window to an auto that does not have power windows without additional wiring? Paradoxical to me.

If I wanted to add power windows to my car, I'd remove the door card, mount the motor and whatever bracketry is needed,then plug the wires into the socket hidden near the hinges where the rest of the wiring to the door also terminates...
(cables for heated mirrors, door locks, power windows and so on, are all gathered in a thick cable that ends with a screw-mount connector that fits into the door. So every cable is there inside the car, they're just missing the final bit to the non-existent motors)

House automation will not become really practical before the required wiring is put in place as the building is built, or that they at least take it into the design process and puts in conduits for later use.

Loopy Byteloose
09-07-2011, 05:25 PM
Hmmm... Are all cars really wired to accept electric window motors these days? I haven't owned for over 20 years now and my motor scooter doesn't have any.

Okay, setting aside the debatable example, I think you still see my point that new wiring will at times be required.

What I am try to do is present feasible segments for development as one manufacturer is NOT going to take on a complete home automation package for all and everything. It is going to take getting a combination of products that work together with some network and communication standards/choices for the mutual benefit of all the manufacturers involved.

Some examples,
In Taiwan, we already have IR control in nearly all new air conditioners: centralized or window placed. So it makes more sense to work with the IR than to do something else - like wireless. And IR is nice because it is cheap and communications are contained to line of sight and usually in one room. That seems to tell me that each room should have an IR transciver connected to a central network.

Other areas need better products, like better X10 light switches or we have to seek new alternatives, IR controlled light switches that operate all kinds of loads or the more complex items.

Some areas may need new development, like IR controlled electrical outlets, or table lamps, or floor lamps. And while I don't need automated doors and windows, there may be some demand for such. And also, automated curtain and window shades would be desired (which I suspect are already available).

In some cases, an automated home might lead to new applicances - like a freezer/microwave combination that moves a meal from storage to table ready. Some applicances may take a long time to evolve, like refrigeration that keeps inventory of everything in it (it requires developing a database of items and a labling system that are standardized lables).

The only way home automation is going to become wildly popular is when there is a near complete catalogue of good product choices. I doubt that pre-wiring homes as a starting point will become popular as different owners may want to do it differently. And wooden stud wall construction would take one approach and concrete walls (here in Taiwan) would require another. If you have attic, drop ceilings, and crawl spaces, you have other options.

Above all, this choice of home automation should be a feature that adds value to a home, so that the next buyer is pleased to buy it and see it as a good deal -- not just a way to fit your home to personal taste. After all, it is somewhat of a capital investment.

Loopy Byteloose
09-08-2011, 02:20 PM
More about automated light switches and electrical outlets.

To begin with, I am not encouraging you to do this if you are not an experience electrician and it is not okay to do so where you live. I used to be a Licensed General Contractor and have rewired my own home myself with proper electric permits as allowed by the State of Oregon - other states may not be so considerate.

I located Magnecraft Latching Relays at Mouser. There are very nice ones that are rated 12amps and 16 amps. I guess the 16 amp devices would be best used in line with 15amp circuit breakers. Lighting is usually on a 15 amp circuit.

If you wanted to create a Control box with all the lighting for the entire house next to the Circuit breaker box, you could then do a couple of simple modifications at the boxes that have the individual light switches.

First, just connect the 120VAC in the light switch box so the light circuit is always complete. You will later divert the switch function to the latching relay from the circuit breaker that feeds the particular lighting. For now, only the circuit breakers will turn the lights on and off.

Second, pull low voltage wiring - you have a choice of 12VDC, 24VDC, and 24VAC - depending on the kind of relays you select. I'd probably use the 24VDC for long wires with possible voltage drop. This wiring would need a supply at the same box as the latching relays. And you would need to find a way to get the wire to go all the way into the original light switch box.

Third, take a blank light switch plate and install a momentary contact switch to toggle the light on and off.

If you have outlets you want to control, you don't have to pull the low voltage wire anywhere - just have the digital network provide a pulse to toggle them on and off.

These are nice industrial quality latching switches that have LEDs to indicate the position of the relay at all times. Since the switching is converted to a momentary pulse of a lower voltage, there is not a lot of problems with programming. And since the wiring is 24 volt or less, it is much safer in terms of shock and fire hazard.

I think the relays are about $15 each, so 10 rooms could be done with $150 USD of relays. And the rest of the automated control would be centralized next to where the electrical service panel is. If a relay fails, it can be unplugged and replaced like a broken light bulb.

In general, pulses at the light switch would override network commands unless software to sense condition and to take over control from the light switch is imposed.

These latching relays are DPDT, and at most you only need SPDT to control just about any light. Multiple switches on one lighting circuit are resolved by the momentary contact - not by using SPDT logic (as is traditional with light switches). There are a lot of clever ways you can combine these. but I am thinking of merely SPST use. You could have the other side of the relay provide a network of indicator light, but that is getting a bit complex.

09-10-2011, 02:38 AM
I have been creating a home automation slowly over the last year. I am using a combination of RF X10 and ZWAVE. I use ZWAVE for the load switches. a few dimmers and many relay output (for my HF Compact fluorescent lights). I a few switched plugs as well. The Mesh network of ZWAVE is working great. I use the HomeSeer application to control it all and the RF-X10 for some very inexpensive remote controllers. My front door lock is zwave controlled and about half of the lights and fans in the house, so far.

While the load controllers are expensive ($45-$70) the ZWAVE protocol work very well. I wish it was not proprietary so I could interface some prop stuff directly into the mesh but I can still use HomeSeer to bridge between ZWAVE and X10 and a few other protocols if I need to.

It is great to be getting ready for bed on the second floor of my house and pushing the "Bedtime" button to lock the front door and turn off all of the lights (that I have selected).

I also have it set to turn off the TV when it is my son's bedtime. No procrastination because the computer does not care if he begs for 5 more minutes, it just turns the TV off when it is time.

I should also mention that the only battery that I use is in the front door lock. I have a motion sensor in the entry way that triggers a light but I bypassed the battery for that and it runs off of a wall-wart and a convenient plug.

09-10-2011, 02:57 PM
Okay, setting aside the debatable example, I think you still see my point that new wiring will at times be required.

I think this means "no additional wiring for items that are already installed". Of course new installation items need wiring, this is a given. The objection is to any requirement for additional wiring for control to be run for items that are already in place.

I saw material about using visible LED light for control. The LED is modulated to send control to to the targets, and to dim the lights. Of course, this method has trouble with sunlight, and all the devices in a given area recieve the same data stream. Anybody look into this?

Lots opt ions, lots of things to consider. Perhaps a solution does not have to appeal to everyone with a complete catalog, but simple address a specific need, towards BUILDING a catalog.

09-10-2011, 03:26 PM
Lots opt ions, lots of things to consider. Perhaps a solution does not have to appeal to everyone with a complete catalog, but simple address a specific need, towards BUILDING a catalog.
Could you explain a little more?

Loopy Byteloose
09-10-2011, 05:02 PM
I am all for building a catalog approach to home automation solutions.

The simplest fact is that some of us rent and don't own, others own their own place. This in itself indicates that more than one solution to automation is likely needed. One could even automate their own work space with portable solutions.

As far as the 'No New Wiring" mandate, I feel that it is time for many hobbyist to get real. To do a really good job with home automation, one has to do things with 110VAC and 220VAC and in circuits that provide as much as at least 30amps (like electric baseboard heating and ovens). And some how, lighting control needs to become centralized rather than distributed. That is just a fact of life.

What I am trying to say is that one cannot do all of this with circuit boards and pull ins. An in many cases, the core device is a latching relay such as I have mentioned. The big advantages with latching relays are that it doesn't require constant control voltage to maintain its position - it takes a low voltage pulse and remembers, and if the power goes out and comes back later, it still remembers.

I also think it is appropriate to suggest that some other skills - carpentry and painting and such - are going to be required to do a really slick home automation.

This doesn't mean that I completely exclude X10 schemes. I just think that there is a right context for X10. If X10 was built into lamps - both table and floor lamps - it might be really slick. Still, good switching is going to likely end up with mechanical relays doing the job. There has been work done on creating a better coding scheme that works like X10. Why not develop a public domain standard?

I also feel that since TV, stereo, and A/C all use IR; a IR bridge of some sort needs to be considered. In addition to the IR bridge to the rest of the network, a handheld IR controller that works with everything IR that is in a room would be great too. In one alternative scheme, no X10 would not be required; all the devices within a room could be IR controled.

09-11-2011, 04:02 PM
Could you explain a little more?

This is in response to the statement:

" The only way home automation is going to become wildly popular is when there is a near complete catalogue of good product choices. "

Just saying it is difficult to eat the elephant in one bite. It is sometimes advantageous to address one specific need and create and implementation that fully addresses that, and then move on to the next. The goal should not be "wildly successful" but instead an elegant and effective solution for each individual need addressed. Each success will build toward a catalog, but the catalog is driven by stated needs that are addressed, rather than an ambiguous requirements for a "complete catalog".

09-11-2011, 04:26 PM
I think it should be built-in to the home when they construct it.
No wall switch should ever control a outlet/light fixture directly, e.g no circuit in series.

Even if the owner does not want it automated at first, every switch (low voltage) should go to a central location.
This center has independent 120v wires (or maybe a future 24v dc standard) running to each and every outlet/light fixture.

It would then not be hard to add automation to this system later.

The plumbing industry have gone this way and now have cheap plastic tubing going to each and every faucet/toilet/shower in parallel.
So no more hot shocks in the shower due to some one flushing the toilet next to it.
So if they can do it the electrician industry have no excuses.

09-11-2011, 05:15 PM
Home automation with a view to conserving energy is an interest of mine and I have been compiling some information in the areas outlined below. Perhaps this list could be used as a starting point for the catalog.

Home Automation System Modules

Access control:
Internet/Text messaging

Alternate Energy:
PV Systems

Communications Network:
Wired RS485, RS422, RS232, Other
Wirelsss RF
Wireless IR
AC Power Line

Communications Protocol:
As simple as possible

Heating Ventilation Air Conditioning:
Standard Gas/Oil/Electric
Active Solar
Passive Solar Motorized dampers

X 10
Low Voltage Latching relays

Interior: PIR and door/window switches for intrusion detection
Interior: PIR for automated lighting
Exterior: PIR for automated lighting and possibly intrusion detection
Smoke, Fire, CO, Gas, Flood/moisture sensors

09-11-2011, 07:49 PM
I have been doing some looking about, and the X10 power wire hardware layer is really much more primitive than I expected. Without pulling new wires, this leaves wireless. X10 wireless was kind of spotty but lookee what I found over at sparkfun: http://www.sparkfun.com/products/10253 That's about USD$10 for a complete Bluetooth node. That suggests Bluetooth, thanks to the commodity SMD assemblies, might be cheap enough to serve as the backbone of a home automation network. This would have many advantages, not the least of which being that devices capable of joining it are already ubiquitous.

Loopy Byteloose
09-12-2011, 05:19 AM
Biomass? That would be methane from animal waste or alcohol from fermentation of vegetable matter, wouldn't it?

A little far fetched for home automation, but then again if your home is a pig farm - maybe not. I have a friend in Thailand with a pig farm and has accumulated methane generating mechanical power for cooling the pigs. Not yet anything for conversion to electrical power, but I must say that I have visited him and the whole scheme is rather large and rather stinky.

Fermentation of alcohol is another interesting alternative. But the good old USA has the ATF that may come to your door. Again, it all depends on what your definition of a home is. Do you have a steady supply of sugar cane?

09-12-2011, 05:33 AM
Maybe one cow for everyone,is a little much.We have some gov grants toward green energy-methane is one.Farms have an oder yes but with a digester its captured and put in a double walled tank outer wall is filled with water I think.Ive also seen something on new generators to power a home off a gallon of water a day.It does some electrolosis on the water and burns the hydrogen and oxygen as gas for the home.The electrolosis equipment was still pricey due to a rare element that was costly to refine.Over time the price was to drop considerably.Its becoming really common we have had a methane digester where I work for like 10yrs.They even have a google sponsored methane thing that is at the local land fill.

Loopy Byteloose
09-12-2011, 01:15 PM
From what I saw, 100 pigs provide an adequate source for a methane digester. In Thailand, they used a rubber bladder about 25 feet long by 12 feet wide. All that powers a modified Nissan automotive engine of about 1800cc, nothing very large. But not really enough for creating surplus power to put on the grid. The method drives the engine which drives large fans for cooling the pigs and an evaporative water wall adds to the cooling.

The benefit is that the pigs grow faster and stay healthier when they are not subject to excessive heat.

As you can see, 100 pigs in their own housing and a digester begin to take some serious space. I doubt if one cow would do much. I don't thing the stink is escaping from the digester - it is just a pig farm with 100 pigs that stinks. The whole building for the pigs is on a hillside and the stalls can be washed down from top to bottom. All the run off goes into the digester.

You also have the noise from the engine to deal with.

Alternatively, Germany heavily subsidized solar energy the results have been that it is installed just about anywhere. And now, we are beginning to identify architectural features that create steady high winds for localized harvesting.

Bio-methane has several problems. First is very low pressure: 1-2 psi. This means that fuel lines are large, like 2" plastic pipe. Second, it is very wet. Third, it needs to be scrubbed for SO2 in order to not damage the engine. That is usually done with an inline tank full of steel shavings. And fourth, it is very high in C02, that reduces the heat content of the fuel by as much as 50% of what you can get from a pure, high pressure methane fuel. Many farmers have gone to using a combined diesel/methane engine to get real power and reliability out of bio-methane. But the investment is roughly 10 times that of a modified Nissan AND you need 10 times the animals to justify the costs. Pretty soon you don't have any neighbors, except for pigs. And you are still buy diesel. BTW, eventually someone has to clean out the digester, right? ewe.................

In sum, there is a real advantage to visiting and observing something in use. I learned about the latching relay system when working in a large warehouse that wanted to replace all their florescent ballasts to conserve energy. The light switches look as if they are 110 volt, but they are entirely a low voltage system. There is an outfit --- Douglas Lighting Controls, which provides complete ready panels for 24 relays and with the low voltage power supply builtin. All UL and NEMA approved.

09-12-2011, 10:03 PM
Biomass? That would be methane from animal waste or alcohol from fermentation of vegetable matter, wouldn't it?

A little far fetched for home automation,....Do you have a steady supply of sugar cane?

Maybe the goal could be switched from "selling energy to the grid" to "sustaining a small family"? Biomass doesn't necessary have to be limited to powering HVAC


09-12-2011, 10:14 PM
I think it should be built-in to the home when they construct it.

That's a really good idea, but around here it is not something that a builder "does", it might end up being a very expensive add-on.

I wonder what kind of gig it would be to install the automation wiring on new construction? Is there even any "standard" to follow to anticipate future needs?
If there isn't a specific set of systems to be automated, its hard to define installation for appropriate controls.

Maybe the first step of the "catalog" is to discuss the systems to be automated, and the control options?

Installing at time of construction would be a nice way to go.

09-12-2011, 10:57 PM
prof_braino brings up a very good point about local builders, and I'll add a side note about the Code. In places where Code approval is necessary it doesn't matter whether a method is better, it isn't permitted unless it is in the Code. And different standards apply to residences and businesses. I can imagine people being very reluctant to allow an installation that is so unusual a normal electrician might not understand it.

And this brings me to prof_braino's point; about 10 years ago my parents had a house custom built in a small Mississippi town. They wanted a modern place and had the money to pay for it, so they specified steel studs instead of wood -- nobody would take the job. Oh, they're in the code and even available because of industrial construction, but none of the industrial builders wanted to build a house and none of the residential builders wanted to mess with the steel studs. So no steel studs. This phenomenon erased several other features they wanted, simply because contractors didn't want their men to have to learn a new technique for one job. They did get the metal roof, but one of the workers fell off it in the process of installing it. (He survived.)

So even if you're buildinga new house you may find yourself starting with 110V series taps to the light switches just because you can't find an electrician who will do anything else. If you want it to have a chance to become popular, best to work with what nearly everybody is already going to have.

09-13-2011, 02:45 AM
@Loopy Byteloose.

I included biomass because it is a viable source of energy for rural homes and businesses, and could be used to generate heat and electricity for urban areas. It includes methane from animal and human waste, fermentation of alcohol from vegetable matter, conversion of plant and animal products to synthetic crude oil, and use of lumber/paper mill waste (tree bark, sawdust, etc.) to produce heat and electricity.

I am also quite familiar with and impressed by the simple elegant design of the Douglas Lighting Controls. They use latching relays that only require power when switching and are rated at 20A 347V. The low voltage switches use 24VAC and use 2 diodes to send the negative or positive half cycle to switch the relay on or off. Several relays can be controlled by one switch or one relay can be controlled by several switches.


I agree 100% that the best time to install the wiring and such for home automation is when they build it. The same would also be true of of alternate energy installations.

My previous house was in a new subdivision and had all the wiring for a home security system along with wiring/pipes for a central vacuum done while it was being built. Made for a much neater and far less expenive job.


That's a really good idea, but around here it is not something that a builder "does", it might end up being a very expensive add-on.

This would most likely be a job for a subcontractor. It makes sense to contract out low volume and specialty work that does not go into a large percentage of homes.

I wonder what kind of gig it would be to install the automation wiring on new construction? Is there even any "standard" to follow to anticipate future needs?
If there isn't a specific set of systems to be automated, its hard to define installation for appropriate controls.

There are standards and standard products in the commercial and industrial building automation arena. Some of those standards and products could be applied to home automation systems and some would be overkill.

Maybe the first step of the "catalog" is to discuss the systems to be automated, and the control options?

Absolutely! I would suggest we start with the HVAC and lighting system since these are where the greatest savings in money and energy can be made.


Re: Contractors, the Code, and local Building Departments. These are the biggest obstacles to any advancements in improving home construction. It may be possible to have an engineer approve the plans in order to get them accepted by the building department but that can be expensive, and still leaves you with the problem of finding a contractor to do the actual work.

Loopy Byteloose
09-13-2011, 06:28 AM
Many, many years ago, I majored in Architecture at the University of Oregon and we were presented with a new class by a professor -- called Mechanical Equipment of Buildings. He, John Reynolds, also authored what was then considered a ground breaking text by the same title.

He did much early work proving passive solar is feasible for residential housing. So the current 4th edition might be an interesting reference to this topic. Nonetheless, the idea of home automation might best be divided into fundamental systems and 'goodies' that people want to pimp out their crib. We might even coin a new phrase - 'I-crib'.


And Sweets Architectural Catalog, which has now morphed into Sweets Network may be very useful for locating solutions already in the marketplace for just about anything architectural.


09-13-2011, 03:27 PM
Maybe the first step of the "catalog" is to discuss the systems to be automated, and the control options? Which is exactly the point of the thread.HVAC and Lighting Systems then.
@Loopy Byteloose "I-Crib" Is awesome LOL

09-13-2011, 03:45 PM
I-crib is really groovy idea. I suggest changing thread title to "i-Crib Total Home Control and Automation" or such. :)

BUT, we start crossing the line from micro controller / software engineering to residential construction engineering, which is out of my scope. At this point, I can only verify that requirements are quantifiable and testable. (Which I will do if you guys think is would be helpful). I know "about" this stuff, but I would not want to have somebody's kid or granny fry because I made a stoopid oversight about wiring.

Do we need to bring a residential design architect to the discussion, or does one of the current participants have this background?

Loopy Byteloose
09-13-2011, 03:49 PM
I am having trouble with what some of youall consider a 'home' in the term home automation.

Please try to get a grasp of the scope and scale of this.

We get into systems that are far beyond the scale of a normal person with a normal home. That was why I challenged 'bio-mass'. It really is an enterprise component with serious capital outlays that only a working farm can afford. (Don't get me wrong, I like automated working farms and am in love with greenhouse climate control, but this is not about that.)

I am NOT trying to limit homes to something like 3 bedrooms, 1 1/2 baths, and 2000 square feet; but I think that the primary purpose should be places that are 'on the grid' and have people working outside the home for an income.

If you take a look at Reynold's text, Mechanical Equipment of Buildings:4th ed; you will find he also covers material and issues well beyond the 'home' context. But he does seem to separate his discussions of them so that solutions can be found that are appropriate to the context of a dwelling.

Youall are welcome to take communal ownership of the "I-crib" or "I-Crib" as a project name or identity. It is fun and I am not attached to fame or glory or greed as far as Parallax Forum stuff is concerned.

And yes, there has been a PERSISTENT DILEMMA in the world of micro-controllers that anything fun soon moves over to include the 'electro-mechanical' world. But don't be too narrow, or there just isn't any room for fun. Each of us can promulgate his own idealized "I-Crib". I certainly have my own biases that I am not about to let go of -- others have theirs. But we might buzz back new creativity at those Arduino people with the Parallaxians and their I-Cribs. (What do I need a shield for, I want an I-Crib.)

A confession - I dropped out of the UofO architecture program because I couldn't see how I'd ever make money at it. (All successful modern architects seem to have one thing in common, they married into a rich and powerful family)

Nonetheless, I eventually did become a Licensed General Contractor in Oregon and built homes as well as restaurants and other commercial structures until 1983 (when construction went bust due to a 20% prime rate). In the past, I often provided free home design services if I was hired as the contractor. Similarly, I'd drew plans for anything that required a building permit as part of the package for working with me. Other construction project experience included nuclear reactors (Hanford Area, Washington State); major office buildings in San Francisco as a journeyman carpenter; and major building foundations in the San Francisco Bay Area as a Cost Estimator and Bid Negotiator.

In other words, my weakness is the electronic hardware and software coding side of all this.

09-14-2011, 04:46 AM
When I posted my list it was not my intention or expectation that all or even most of the items would be considered for inclusion. They are folders used by me to accumulate information on those topics, and was intended as a list to select items of interest from. On the other hand, I see no reason to exclude any of them if there is some interest shown.

My personal interests are in the use of passive and active solar systems and automating HVAC, lighting, and security to maximize energy savings and maintain a comfortable and safe home environment.

09-14-2011, 10:02 AM
I think we need more than one controller system.

One is for HVAC and possibly security, and the other(optional) is for Power generation/distribution.
Of course, they need to be able to 'talk' to each other, via a well-defined protocol(Power may issue a 'Low power situation' message, causeing the HVAC to shut down 'non-essentials', a 'Limited throughput' to make the HVAC select(priority scheme?) which units runs when.(First washer, then the fridge gets a boost, the dryer, later on, the freezer gets power. ), or a 'Low cost' to indicate that any waiting tasks(washing, drying, recharging of large batteries and so on) can be done.
The HVAC can signal that it's in a 'Low usage' cycle so that the Power unit can dump excess power to a 'secondary storage', or even deep-cycle batteries to reclaim capacity. (If the battery tech supports something like that? May as well assume that some types have that requirement)

Alternate methods of storing power is 'heated salt' (solar power systems sometimes use large tanks of salt and generates electricity by pumping in water for steam),
a large tank of water higher up... ('fast response' power plants use lakes in the mountains... In times of low power demands they pump water into the lakes, then dump it through turbines when the grid 'spikes'. No reason why a 'scaled down' system shouldn't work for a home power system?)
Lage banks of batteries, of course...
Portable electrically powered units.(Maybe not your iPod, but consider the battery for your drill, the leaf-blower, hedgetrimmer, tractor or electric car...)
and yes, it's possible to build an electric tractor. In fact, battery weight isn't a problem on tractors... and if you have two or more detatchable packs that you can easily swap between... The problem here is how to let the system 'know' for how long these devices will be available to 'borrow' power from before they're needed next, and how much can be taken out.

09-14-2011, 12:50 PM
I love both your ideas and comments (Kwinn - GadgetMan)and will try to use as much as we can.While there is much to be considerd for communication and power.I think we should focus on things like what else needs communication and power.Like I heard someone say I'd like to be able to draw a tub full of hot bath water to just the right temp.On my way home from work.Now we need stuff for that.Simple the mechanics can be done.Moving on...Some modular design should be used.

Loopy Byteloose
09-14-2011, 03:24 PM
Your list is a good one. I just was worried that the scope of things was getting too large and moving away from home automation into other concerns.

There is a tendency to think that one centralized system is good. In many cases, it means a failure or a need to pull the system off line drives everything down - not really a good outcome. Multiple controllers that are tasked to one aspect apiece might be more useful. I suppose that centralization of data gathering (in the form of logs of activity) might be a useful research tool to find out what people really do as compared to what they think they want is a useful methodology. But we already manage multiple layers of systems in our home environment without any automation. For instance, when I leave open a window; I am thinking of security, of the near-term weather, of the interior climate control, noise either going out or coming in, and providing fresh air. All this happens without any automation.

So this all leads to the possibility of creating a non-automated environment with extensive data gathering as a first step toward useful automation. I suspect this has been long ignored as data gathering used to be expensive. For this, I am thinking of something like the LInux-based BeagleBoard because I can have it acquire data in a centralized location, with low power, and I can do a lot of the Log work in a shell script language. Data can be fed into it via RS232, LAN, or by other means. And best of all, data can be easily offloaded to be reviewed on any computer.

Modular design already exists in many cases if you just look at what is out there in electro-mechanical control. But this may not be the modularity that you conceive of in your own mind. I am beginning to think I need to write up a paper that explains my own ideal I-Crib according to my own personal preferences and then have other critique it for feasibility. It we all did that - with an open mind, some new conclusion might be made. This is conceptual stuff, not the kind of work that is done with solder, components, and IDE. That would come later.

And for everybody,
I really don't think we need a residential architect to grasp all this. We aren't starting from scratch with a piece of bare ground and a building budget. I don't think any of us will be moving walls or adding additions to their homes via this. The main skill set is that which is more akin to a handyman/remodeller. And even then, the majority of us are not going to reinstall window frames or add significant features to a building. I have personally been living in a one room plus bath dorm room in Taiwan for 17 years now. That is my I-Crib as it is, but there are ideas and ideas applied to gadgets that would make it all so much better. In my case, I really don't need a security network. The hallways and the front door already have a security camera system that the landlord provided. And I can't automate lighting by breaking into the existing wiring as it isn't my building. So I am thinking more of an IR network and a data gathering computer as the starting points. Eventually I could add more sensors and features as I see what the data is omitting. From that, I can begin to see the kind of things that I'd love to further develop. I do admit that I have immediately omitted X10 as I just don't have a lot of confidence in it.

So I guess I have to write something presentable to defend my own preferences. That all may better be done in Parallax's 'Blog Space'.

09-14-2011, 04:00 PM
What you described for more self automated control of a window is good thought also like how it would be identified by the security and HVAC systems as it should be.When one configuration counter acts or inhibits another system there should be an alarm of some kind.Like you have the ac on and the window open.By self automated I mean the ability to sense rain and close itself in an auto mode.
Id like to hear more on your thoughts of useful automation.

Loopy Byteloose
09-14-2011, 04:14 PM
I just fear I might have to write a book. I have already mentioned Reynold's text. The first edition was inspiring and the 4th edition only seems to have gotten much better. And I spent a lot of time in the UofO Architecture library looking at Sweets Catalog.

Here is a practical personal example.
It would be easy to separate HVAC and security by having all the windows NOT open, or at least providing an ample alternative source for injecting fresh air. It might even be more acceptable as the fresh air could have dust and humidity removed prior to being brought into the home. My biggest problems here are dust and humidity as my air flow comes in a window and goes out a door. I've managed to get the humidity under control by keeping the A/C at 27 degrees C on a 24/7 basis and running a second fan on the opposite side of the room. But I can't filter all the dust (Kaohsiung is a rather dust town, steel mills and petroleum refineries).

At 27 degrees C, the dew point seems to keep the humidity at about 30%. So running the A/C is a brute force solution. If the temperature goes up, the humidity in the room creeps up to 70%, the walls get wet and slimy, and my books begin to mildew.

Due to other factors in my building. It is almost as cheap to run the A/C 24/7 and have the humidity under control as it is to only run it when I am here. But that gets into a lot of thermal facts and the shady location of my room.

As you begin to see, there is a trade off between the physical building, the kind of systems employed, and degree of control imposed. In some cases, you have to enhance all three in order to get the best results.

09-15-2011, 02:01 AM
I really don't think we need a residential architect to grasp all this. ... I don't think any of us will be moving walls or adding additions to their homes via this.

OK, fair enough, that's your opinion. Here is the basis for my suggestion: I DID need a residential architect on my project, and I DID move walls. This is very common. And because we strictly adhered to code and safety requirements, and common sense, nobody died when we had an electrical malfunction. Previous owners had done dangerous things, like running wires through the attic without conduit, "swapping" neutral lines, and wiring light sockets with extension cord wire. "Quick and cheap fix before the sale" is also very common. The electrician I hired fixed everything he found in the course of renovation, but he missed a swapped neutral (the circuits were not on adjacent breakers). This is also very common, mistakes and oversights get made every day. There was no issue until we needed to replace a faulty outlet, when the breaker was switched off, and the other breaker was left on (we did not cut power to the entire house to change a single outlet), a ground fault outlet failed and burned. All the fire and debris were contained in the conduit box, only the smell got out, alerting us that there was a (potentially fatal) issue.

09-15-2011, 03:19 AM

I agree that there are situations where more than one controller system may be needed, but for a small home, apartment, or small business, a system based on a single Propeller chip could be a perfect solution. Temperature and humidity change slowly so there is no need for rapid response in that area. Automated lighting needs a fairly rapid reaction to sensors but very little processing (PIR detects person in room – turn on lights in room. No motion detected in room for X minutes – turn room lights off.). The security system (intrusion detection, fire, flood, freeze alarm, power outage, etc) may require rapid response and somewhat more processing for an event, but even that is well within the Prop's capability.


At this point my approach is to split the system into individual modules, ideally each running in it's own cog. This approach has the benefit of splitting the software into well defined functional areas and allowing the sensor data to be shared by the various areas. The PIR sensors for example could be used for intrusion detection when the home is unoccupied, and for lighting when the home is occupied.

Module 1 – Data Collection: Uses objects from the OBEX (74HC165, I2C, MCP3208, Multiple Serial Port Driver, IR, etc.) to gather data from the various sensors, format the data, and store it in an array in hub ram. This data is used by all the other modules.

Module 2 - Control Output: Uses objects from the OBEX (74HC595, I2C, Multiple Serial Port Driver, IR, etc.) to output commands to various systems. This module is used by all the other modules to control the devices they are responsible for.

Module 3 – Access and Security: Monitors the sensor data stored in hub ram for intrusions, power outages, high/low temperature, flooding, smoke, fire, etc. and performs appropriate action based on occupancy status.

Module 4 – HVAC: Monitors internal and external temperature and humidity readings, controls furnace, humidifier, heat exchanger, blowers, motorized blinds, etc, and selects the most economical method of maintaining the current set temperature.

Module 5 – Lighting: Monitors PIR and light level sensors and turns on lights in that area if required.

Module 6 – HID: Input settings (temperature, humidity, actions, etc.) that controls the system behavior. This could be a text file stored on an SD card.

Module 7 – Data Logging: Logging of events, average readings, faults, etc. to SD card or other destination.

Loopy Byteloose
09-15-2011, 09:50 AM
I suspect that a good architect is rather hard to find. 95% of US construction doesn't include one and the would like to charge a 10% fee on the total cost of a project. Small projects just can't afford one. But more important is a good electrician - maybe a good plumber and a good builder as well.

Regarding the topic of fire hazards and electrical, the great majority of failures are contained inside junction boxes and it is very important to use them. In San Francisco, it is most often necessary to put everything in steel conduit, but in Oregon, they pretty much accept ROMEX wiring between boxes. Primarily that is due to a building code rating by the degree of risk of loss by fire. It pretty much is an insurance company thing, not an engineering requirement.

But the electrical box, not only offers protection from fire - it is also pretty much the modular for putting in switches and controls, even when low voltage. So learning something about how to install 'remodel boxes' (the ones that you can just fit in a hole in the wall board) may be helpful.

But if you buy a fixer-upper with dire need for correcting improper wiring, it is a bit beyond home automation. If the bum that previously owned the home didn't know anything and just used the cheapest and most cosmetic means of wiring, it is all 'buyer beware' - unless there is something in your real estate transaction and title insurance that certifies the safety of all the existing electrical. In many parts of the USA, rural agricultural buildings - not occupied by people - are exempt from building permits and electrical inspection. Or at least they used to be.

Still, the smoke and odor from a fire can often be the worst and most persistent part of fire damage. So it is very important to avoid it at all cost by good wiring practices and expert guidance. Oregon used to allow aluminum wiring and I suppose one could be unlucky enough to buy an all aluminum wired home. It has now pretty much been abandoned as the aluminum oxides at the junctions and switches and outlets are constantly failing in a dramatic way. They had a protective gel that was supposed to prevent it, but it just didn't last.

I need to think about your Module approach. There is nothing specifically wrong with it and it is a good working hypothesis, but I am considering other things - like adding an IR sensors and a latching relay controlled by a PIC to my overhead lighting. In that way, I can take a univeral remote control - use the TV side to control the TV - and use the VCR side to control lighting throughout the room. So you see, there would be an IR sensor, relay, and microcontroller installed where ever I have a light to switch on or off. Of course, the Propeller could provide another IR transceiver set up as data gatherer and an override.

What would happen to the wall switch? I'd either remove it to permanently supply the IR sensor and microcontroller OR I'd leave it in place as an override means to shut down the circuit (though I suspect this would only be a temporary need.)

09-16-2011, 02:50 AM
@Loopy Byteloose

Nothing wrong with your approach. For the living space you describe and taking into consideration the fact that it is a rental it may be the best way to go. Even for a home that you own it may be better to replace switches lights, receptacles, etc. with modules controlled by IR commands. In many cases it is far more cost effective than rewiring the home. No reason (other than being somewhat forgetful) that IR input and output could not be included in the modules.


I missed posting the “Control Output” module in the original post and have added it. With Loopy jogging my memory I will also go back and add IR to the Data Collection and Control Output modules.

In case anyone is wondering at my choice of module division, it is so that all of the modules except Data Collection and Control Output can be written without any consideration as to how the input is acquired or the output is controlled. If the HVAC module reads the temperature variable and finds it higher than the set point it sets the AC ON variable to ON. It does not care if the temperature reading or AC ON command is sent by serial data, I2C, IR, RS485, morse code, or smoke signals. Receiving data and outputting commands is the job of the Data Collection and Control Output modules respectively.

09-16-2011, 04:13 AM
So what would be next?

09-16-2011, 05:18 AM
So what would be next?

Next would be deciding the format of the data in and command out arrays. This would be deciding on a format for all the inputs and outputs for a typical home control system. For example PIR detectors would be binary. Either motion is or is not detected. Temperature would most likely be byte (8 bit) or word (16 bit) depending on whether an 8 bit or 12 bit adc is used. Since we are talking about values that are typically between -40 to +120 for farenheit, or -40 to + 50 celsius 8 bits would be more than adequate. Relative humidity (0 to 100%) would also be a byte variable.

For outputs the variables would typically be binary or byte. The furnace, AC, lights, or humidifier would either be on or off. Any fans or blowers would be on or off, or set to a specific speed (0-100% or 0-255) so would be byte.

Loopy Byteloose
09-16-2011, 09:29 AM
Regarding HVAC, the measurement of humidity and temperature are directly related to dew point. So I suspect that some form of dew point calculation may be useful and informative. There are a lot on nasty and annoying things that can occur at hitting dew point. Water begins to condense on windows, some plants (like orchids) will suffer, mildew grows and 'dry rot' occurs, and this is also the source of 'sick building syndrome' or Legionarre's disease.

In other words, if you didn't know about dew point, it might help to review it. A/C equipment needs to have periods of running without cooling in dry ambient conditions in order to blow out accumulated crud that includes nasty bacteria. I even spray the intake of mine with a weak Clorox solution before doing so. It would be nice if this could be automated or at least scheduled for regular attention.

While I live in a sub-tropical climate where high humidity is a indeed problem; many of you live in areas where lack of humidity - especially during winter months - is a problem. So location and season variation need to be considered when programing. Extreme low humidity contributes to breathing discomfort, nose bleeds, and nasty static electricity build up.

Regarding my own vision of an I-Crib, I think 3 levels of network would work best and I am working toward that as a proto-type. I am not just working on IR links, but that happens to be the least developed area at this time.

Here is what I am thinking with the goal of not having to move once comfortable - and I mean not have to move out of a chair or not have to move to another room to monitor or control household issues and tasks.

1. Within any given room, an IR remote control allows the user to over-ride automation or tweak for specific needs. And to this end, I am working on a IR sensor/micro-controller/relay scheme that would allow lighting and other devices to have individual address identities and be powered from AC lines. The IR remote should work in all rooms and be able to be taken with you. It may be optimal to have the IR remote control working in conjunction with a PIR that senses the presence of people. Together, the over-rides could be enforced as long as the people are present; then when they leave, the PIR would trigger a return to default parameters.

2. Within the entire home, each and every room would have at least one CANbus node that would allow data to be passed on to a suitably located server (I mentioned that I was thinking of a Linux Based BeagleBoard) and that would be available on a local LAN and possibly the internet from afar via SSH connections (secure shell encryption). Data could be gathered from hardwire links or an IR sensor; control from afar could be passed via the same hardwire or IR transmission.

3. The CANbus network would not only gather data, but could also provide a link to control devices from afar and at multiple locations as it allows for multiple masters and slaves. Since it is hardwire and independent of the internet, it would provide a great deal of security and since it is low voltage/low power, it is both easy to install and to provide backup power. Also, the RS422 network it uses can extend to out building as 1 kilometer distances are no problem. All nodes can be polled so that an intruder can't destroy or add a hacking node with raising an alarm condition.

3a - individual micro-controller such as the BasicStamp, the Propeller, and others can easily work as needed with the CANbus via the MPC2515/MCP2551 chip set which is a simple SPI interface.

As you can see, I am not proposing specific microcontrollers - BasicStamps, Propellers, SXchips are all appropriate. If you need a master video terminal with keyboard, the Propeller is useful. If you need a singularly tasked slave, an SXchip or a BasicStamp maybe quite adequate. Much depends on personal comfort with any given device and what the configuration of an individual room requires. Incidentally, I already have made 20 circuit boards for CANbus nodes and populated about 5 of them for testing. Years ago, I had two up and running for months and driven by BasicStamps while connected over a coil of 100' of telephone wire without any failure. (They keep track of their failures.) They sent data back and forth at a rate of about 60 times a minute during that test.

I think this could be described as 'centralized automation with decentralized ability to spontaneously over-ride for transient periods'.

I am very wary of wireless, as it can be snooped and then hacked from outside. And I have read a lot of disappointments about X10 being rugged enough as a network. CANbus has the ability to manage collisions with arbitration when two or more devices try to send data at the same time. Each gets prioritized and can be resent automatically. X10 - as I recall - doesn't manage failures with any notification or attempt to resend. Also, I am quite wary of sharing a LAN as the main network for home automation. There is always the possibility that a rogue user starts fooling with devices. So the CANbus to internet (Via a Tini80DS410) bridge would serve as a firewall between all the CANbus elements and the LAN. A BeagleBoard would be present as a data accumulation server by recieving email from the TINI board. Unimportant devices - like table lamps - can be on the IR network; while critical devices can have more strict security on the CANbus while locked out of general over-rides

Loopy Byteloose
09-17-2011, 06:09 AM
Just a few afterthoughts.

I suspect what I propose can use either a BeagleBoard or a TINI80DS410 as the CANbus to LAN bridge. You don't need both, but the set up would be quite different as the TINI80DS410 has CANbus installed and uses Java as a programing environment; whereas the BeagleBoard would need to have a CANbus interface fabricated from scratch, but programing could be in C, Python, or one of the many language supported in Linux.

I just happen to have a TINI80DS410; but haven't yet purchased a BeagleBoard.

Regarding PIR sensors....
While these are often solely linked to lighting, they can be used in a more comprehensive way to identify that people are present or have left the area. Personally, I would consider more comprehensive associating with several systems - Lighting, HVAC, Security, and communications. The only negative issue is if you have pets that provide false triggers to the PIR as they remain roaming a home while all the people are out. With pets, more thought about what they detect and in which zones they are most important would need to be considered. After all, they detect motion of any warm blooded animal.

09-18-2011, 01:20 AM
@Loopy Byteloose

By 3 levels of networking do you mean IR, wireless, and wired communications? If that is the case then we are on the same wavelength.

I like your idea of an IR link in every room. It should be possible to fit an IR link, temperature, humidity, and light sensor in a module that would fit in a single outlet/switch electrical box. Light fixtures could then be fitted with an IR link and PIR sensor to provide the room with a complete sensor suite for our purposes.

Most of my work has been in the industrial and building automation so I am familiar with Profibus, BACnet, Field Bus, etc. I have no experience with CANbus and my knowledge of it is minimal. I thought it was mainly used in vehicle systems.

FYI, while they share some of the same driver chips, RS422 is a point to point or multi drop standard (one driver, one or more receivers), RS485 is a true multi-point communications network (multiple drivers and receivers). While the Profibus and BACnet protocols can use several physical media for communications most installations I have been involved in use RS485.

In any case the more important aspect is the protocol for communicating the data over the hardware connection and the data itself. Do we use an existing protocol or come up with one?
Take a look at http://en.wikipedia.org/wiki/Profibus, http://en.wikipedia.org/wiki/BACnet, and http://en.wikipedia.org/wiki/Controller_area_network#Technology. None of the protocols would be described as simple to implement. Of the 3 protocols BACnet is at least aimed at building control so perhaps it should be considered.

Another consideration is that the sensors commercially available for this are almost all intended to be wired directly to a control system of some kind. That means adding a uC to the sensors to use them as part of a network. This is not much of an obstacle since there are very inexpensive uC's with built in ADC's and other I/O available, but they do need to work with the protocol in use on the system.

Loopy Byteloose
09-18-2011, 06:03 AM
Sorry, but my 3 levels exclude wireless - just IR, CANbus, and LAN with possible link to the WWW. All wireless communication can be snooped without alarming the network and potentially hacked. Thus, it requires a higher degree of security and still remains a risk. I am all about keeping the home automation network protected with a rather strong moat.

Okay, CANbus is likely RS-485, not RS-422. A technical blunder on my part. I need to take a look at what Profibus and BACnet are, but I have studied and worked with CANbus and like it. One of the more interesting advantages of it is that by using an unusual crystal to clock all devices, it becomes yet even harder to break into from the outside, but its main protect is that there are just too many addressing options for a hacker to monitor in a reasonable time period. Are these others equally protected from snooping?

Right now I am pondering a 'state machine' approach to overall network operation. Here is a preliminary list of levels.

1. All systems off
2. 911 Emergency
3. No one at home
4. Pets at home in secured zone
5. Pets at home and wandering
6. People at home and active
7. People at home and retired for the night
8. Have system revert to all local and manual control (as if there is no automation - for emergencies, maintenance, and debugging)

We would likely need to have a few small data listings for the state machine. So an administrative menu would look something like this.

A. Add an occupant or guest
B. Remove an occupant or guest
C. Reboot to defaults
D. Configure a temporary activity (social event or one-time maintenance)
E. Configure regularly scheduled service calls (gardener/grounds keeper; pool maintenance; house keeping)
F. Add IR device and remote key code selection

Essentially, I have a strong preference to have all the administrative and programing modification to be made via an RS232 port and a dump terminal. The LAN would be able to do things in a limited fashion with an identified user properly logging in and it would send out email to gather data for research and improvement. But the core of the system would be fire walled by having only the one RS232 able to do all and everything.

CANbus with the MCP2515/MCP2551 chipset can work with all and any uC that can support SPI. Of course, there are some uCs that have CANbus build in and are very cheap for local nodes and some of these include ADC pins and internal crystal. The CANbus network requires one twisted pair for communication. So if you add another two wires in the same to power all nodes, there is a minimal amount of new wiring. Critical nodes (both master and slave) can have their own battery backup

Loopy Byteloose
09-18-2011, 12:55 PM
Having said my position on wireless, I am wondering what other are proposing and why wireless is important. Is it a matter of using an IPad or some other specific platform. Or is it a desire to use wifi or another protocol?

My own preferences have led me to acquire hardware that may make me biased. So I am trying to keep the discussion open.

09-18-2011, 09:08 PM
@Loopy Byteloose

I have misunderstood what you meant by wireless. I was thinking more along the lines of Xbee or Bluetooth to connect a sensor located where wired or IR would be difficult or impractical. Most definitely would not want the system directly accessible from a wireless internet connection. At the very least it should go through a secure system.

We also seem to be discussing different levels of the control system as well. I am currently looking at the hardware (bus, sensors,and actuators) and the software required to control the hardware.

I agree that a hard wired system would be the best solution. A 4 conductor cable could provide power and data connections to all the nodes. For my own use I am thinking of using CAT5 with one pair for data and the rest for power if required.

As far as the hardware layer is concerned Profibus and BACnet both use RS485 as one of the options. With RS485 the driver chips actively drive the +/- lines high and low. While CANbus is similar in that it uses two balanced lines, those lines use pullup/pulldown resistors for CANL/CANH respectively. This gives CANbus an advantage in arbitrating bus access where there are multiple masters on a bus. Either one could be used, and both could work with the same software.

As far as choosing between bus protocols go I think that all 3 (Profibus, BACnet, and CANbus) are more complicated than is needed for a home control setup. A simpler master/slave protocol would be more appropriate for this.

Loopy Byteloose
09-19-2011, 04:15 AM
Well, Bluetooth and XBee can also be snooped and deceptive input could be provided. Also both are rather expensive when compared to installing a node on a RS-485 network, Canbus or without.

The reason I prefer IR is that the transmission and reception are limited to within one room. Wireless goes through walls and outside the home perimeter. At some point, you are open to mischief or just conflicts from other Bluetooth or XBee devices. One geeky teenager for a neighbor could amuse him/herself by sending false input on a random basis. Early on, Bluetooth gained a rather notorious reputation as allowing cell phones to be easily hacked. I have no knowledge about XBee's security features. But I feel that the automation should not be subject to flying out of control from any source.

CANbus's added advantage of arbitrating the RS-485 line is significant. Otherwise, when a data collision occurs, messages just get lost. To me, that is NOT adequate automation. A CAT5 cable is 4 twisted pairs, right? If is fine for CANbus or other RS-485. While the data only needs one twisted pair, the others can be doubled or tripled up to provide more power over a long distance at a given voltage; besides it is very cheap to buy. Another alternative is to provide two twisted pairs - one for critical CANbus and a second for "not so important" CANbus, while the rest is power. This is done in automotive where the engine and transmission functions are sometime separated from the rest of the automotive controls.

I like BACnet's scheme and think it provides some good design goals as far as the kind of software objects required. Profibus and CANbus seem to NOT be able to work together, it is one or the other.

I do have to admit that my scheme is rather ambitious. But, I have in mind the kind of network that could accommodate a home of any kind and any size.

That includes a rather large array of HVAC choices as there are lots of different kind of HVAC installed out there. In fact, a lot of America just has heating and ventilation without AC or just heating. In my own situation, I have AC only with a room fan, no heating. Some buildings have heaters in every room, others have central heating, and some building can either passive solar, active solar, or both. Given all the situations, a complete automated solution would likely require multiple sensors and multiple controls. And while temperature and humidity sensors are specific to HVAC, additional ambient lighting sensors and weather condition input may be shared by other aspects of the home automation.

I don't expect one to jump into a complete complex design. By using the CANbus, one might slowly add systems and respective nodes as a need is identified. Every new node can be give a valid identity and polled to affirm it is up and running properly.

For one system, like HVAC - you probably don't need CANbus. In fact Parallax has published a Propeller text that has a very good HVAC system for a ducted system that controls on a room by room basis. I think it just uses RS-232, but RS-485 in that context is a quite simple alternative. See "Programming and Customizing the Multicore Propeller Microcontroller" Chapter 11, The HVAC Green House Model.

Still, I am not after providing just one automation system, but a network that can be revised and added to. It is not uncommon for a CANbus system to have 70 or more nodes sharing that humble twisted pair in a satisfactory manner. And CANbus is being used in aviation for fly-by-wire technology. So it seems quite robust. There is a related development project called CANopen that I believe is public domain.

I have been thinking about this project for several years now in an on and off basis, so it might be quite a bit for someone else to comprehend. But lighting, HVAC, security, weather, pool control, and even the front and back doorbells could be included. It is supposed to be comprehensive. And if one must pull wire, it is best that it is only required to be done once and allows for changes to evolve over a period of years.

09-20-2011, 06:04 AM
I agree that IR has the advantage of being more secure and less expensive to implement than XBee or Bluetooth. I would only consider using one of them if IR or hard wiring were not practical. Do keep in mind though that any room with windows would also be susceptible to having the IR hacked.

At the hardware (driver chip, data bus, and signal) level RS485 and CANbus are not much different. Both drivers use differential signalling and can often share the same network bus. Take a look at the LT1785 driver. It can be used for RS485, RS422, and CANbus.

Currently BACnet over RS485 seems to be the dominant choice for commercial/industrial building automation (HVAC, Access Control, Security, Lighting) but there is no reason the CANbus hardware layer could not be used in place of RS485.

Loopy Byteloose
09-20-2011, 08:26 AM
Yes, BACnet seems to have had the vision to create objects specific to building automation. Thsi is a Pro, or the real benefit. The Con is that using a standard may be more hackable, less secure than a one-off system created in CANbus. I leave it to the buyer to choose.

XBee or Zigbee seem to offer more security and have less exposure to hacking. Yes, IR might be snooped from a window, but Bluetooth might be snooped through a wall at 100 feet. See below for my reasoning in Design Guidelines. From electric garage door openers, to wireless home phones, to Bluetooth, to Wifi - the consumer has had a long, long history of wireless gadgets that claimed security, but really failed. Radio waves radiate in every direction and can thus be easily located and hacked. With a wired network, one has to locate and break into the wire.

Here are some additional thoughts, due to the Title of the thread mentioning "TOTAL Home Control and Automation" with a focus on the word TOTAL>

Home Automation Design Guidelines.

First, Home Automation and Control should be as secure and private as the home without any automation.

Second, Home Automation and Control should offer better ways to conserve energy consumption throughout the home.

Third, Home Automation and Control should permit well-integrated passive solutions into the system and not only provide for active solutions. (This is somewhat a logical extension of the second guideline.)

Fourth, Home Automation and Control should permit local factors to be integrated and exploited so as to offer greater economical benefits (Some sites often advantages of more sun, more shade, wind for ventalation, and so on.)


I do admit that is all a rather broad mandate, but it can be managed. And it adds a great deal of appeal to Home Automation and Control if it is a comprehensive solution.

Just consider what the major energy uses of a home really are.

1. Heating - obviously rooms, but also significant amounts for heating water, food preparation, clothes drying, and heating swimming pools.

2. Cooling - again obviously rooms (in the right season), but also refrigeration and freezing of food in storage.

3. Air circulation - control of humidity is just as much about creating air movement as about temperature control. And heat that accumulates on the ceiling is actually a waste when temperatures drop below freezing.

4. Water - pumping for sump pumps and irrigation can be significant and often forgotten portions of an energy bill.

5. Lighting - actually, a rather small part of the overall cost of energy, but requires a lot of changes to accommodate people according to their choice of activity and their movement throughout the home - all of which are rather spontaneous.

6. Miscellaneous - everything else that I've not mentioned.

09-20-2011, 11:51 PM
The BACnet standard was created specifically for building automation so it's no surprise that it has it has objects for that application. I agree completely with your comments regarding the security of the various communications media but I am not too concerned about that aspect. As for standards making systems more easily hacked, this is a valid point, but that risk is greatly outweighed by the ability to share hardware and and software. There are also various ways to minimize the risks involved.

The network data can be encrypted using a relatively simple algorithm.

Settings for parameters such as temperature and humidity can have reasonable limits imposed on them. Commands to go beyond those limits should be logged and ignored.

PIR sensor data and security system status can be used to determine if the house is occupied. If it is not occupied there is no one to give override commands so any such commands should be logged and ignored.

I like your Home Automation Design Guidelines. They summarize a lot of my thoughts in a clear and concise manner.

Your second, third, and fourth guidelines are the reason I proposed a very modular approach to this. You can pick or create modules to fit the type of system you need.

Loopy Byteloose
09-21-2011, 03:06 PM
I will be doing much more reading about BACnet - either to incorporate its best attributes into a CANbus network or as a complete replacement. At this point I am running out of things to say about a Total Home Automation and Control system. This may be a last post for a while.

What I want to clarify is the Passive/Active nature of the systems involved. I'll use the hot water heater as an example because it is a big energy user and often poorly managed.

Passive measures do not require automation. For a hot water heater, this would include adding extra insulation in order to reduce heat loss, possibly flow restriction to limit consumption of hot water (I really hate these), and solar hot water heating.

Active measures would be reducing the hot water heating cost by not heating water to a ready state on a 24/7 basis. After all we spend about 8 hours at home sleeping and for 5 days of the week we are away between 8 to 10 hours. Why have the thermostat provide the only control and assure water is ready for periods when nobody is home?

Consider that a good blend of active and passive can work out a big energy savings and justify some of the cost of automation. Given that the sun is up in day time only (quite obvious) and that much of the hot water usage is too early or too late to take advantage of solar water heating, the solar energy can be used to provide standby hot water while the conventional heater is shut down during day time hours. With additional scheduling, an electric water heater might only operate when prices of electricity on the grid are at lower rate. And it is likely you can downsize your conventional water heater to a smaller unit.

So this might get you thinking equally about passive modifications to your home as well as automation. Not everything can be solved with a micro-controller. Insulation is one best passive installations for saving money, but there are others. And bear in mind I have just discussed the solar water heating as a separate system. It can cross over to have radiant hot water heating in the floor of the home, or just in certain areas - like the bathrooms, which people tend to dislike using electric heaters because of potential shock. Even if the rest of the house is icy cold during winter months, a toasty warm bathroom floor is a wonderful thing and if it is a low cost addition, it is just more wonderful.

In any event, this also shows how each home becomes pretty much a unique project as something available locally may offer a very good solution. where in other places it won't. Solar water heating requires sun. It seems that even in snow country, one gets a lot of sun due to glare from the snow, but in rainy Seattle, it may not offer up as much savings. Passive solar homes have been able to provide as much as 95% of the heating in locations across the USA (I have a book by John Reynolds that was written and published on a HUD grant many years ago), so the question what needs to be automated becomes quite secondary in such contexts.

Whatever youall do, it is your I-Crib and you have to decide what you want and what you can afford to do. But not all of it is wire, hardware, and software - there is a vast corpus of energy frugal home design information that is available to you.

09-22-2011, 04:11 PM
http://www.google.com/url?sa=t&source=video&cd=3&sqi=2&ved=0CFQQtwIwAg&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DODp ReoKQVXM&ei=ZFx7TtngGtPG0AGbq5y9Ag&usg=AFQjCNHJam1kUb8pouhiDTAsreWnhcpcww

09-23-2011, 04:05 AM
http://www.google.com/url?sa=t&source=video&cd=3&sqi=2&ved=0CFQQtwIwAg&url=http%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DODp ReoKQVXM&ei=ZFx7TtngGtPG0AGbq5y9Ag&usg=AFQjCNHJam1kUb8pouhiDTAsreWnhcpcww

Nice if you have Bill's budget to play with. Also high on hype and short on technical information. This thread was more about what would be feasible for an average home and home owner along with the potential monetary and energy savings. Any energy savings would also result in environmental benefits.

09-23-2011, 04:21 AM
@Loopy Byteloose, Re "....This may be a last post for a while.

Mine also. I think we have said about all there is to say without doing some development work. I agree there are many areas where energy efficiency can be improved by looking at the overall energy use in a home. The exact details will vary depending on the location and climate. I would like to investigate things like using heat from an air conditioning condenser to preheat domestic hot water, motorized blinds to allow or prevent sunlight from entering a room, heat recovery ventilators and flues, etc.

There are a lot of things that can be done to improve our energy efficiency but I think a lot of those things have to be automated to gain much benefit from them. Most people do not have the time, discipline, or inclination to do these things day in and day out.

Loopy Byteloose
09-23-2011, 12:46 PM
I dug into my bookshelf and I have a copy of "The First Passive Solar Award Homes" by the US Dept of Housing and Urban Development. Jan 1979.
It provides a lot of need-to-know info about the use of solar - including how to determine the available sun at any location across the USA and the average 'degree days' to determine how much heating and cooling would be required to achieve a comfort zone. It even has a passive solar dog house design that works.

The point is that the book includes successful designs from all over the USA with solar energy contributing over 90% of the heat in many of the nations coldest climates. Not much automation except fans.

Of course, you may wonder why I have carried this book over so many years and all the way to Taiwan, but that's another story. There are solutions out there that have been successful for decades without micro-controllers. I had originally thought John Reynolds was involved in the publication of it, but now I see he was not. There are 162 houses documented in it, including places like Colorado (with 92% solar heating), Maine (71%), Minnesota (93%) and Vermont (63%). Not all of these are new construction, quite a few retrofits.

And the Japanese make a unit for solar cooling of A/C from hot water accumulated on roof tops. I think it is Hitachi and they make them nearby in PingDung, Taiwan. But they seem to be on a larger scale than single dwelling. A patent for solar ice making was issued in the late 1800s as well.

Life in 2050 for me will be non-existent or sitting in a nursing home at 103.

09-23-2011, 04:05 PM
The paper behind this thread would make for an excellent addition to home automation!


09-24-2011, 05:07 PM
Well, so much for my previous post being the last one for a while.

@Loopy Byteloose

I know that solar heating does not require the use of microcontrollers to work well but their use can enhance overall efficiency and comfort. If some energy savings can be gained without the use of a microcontroller or other electronics, by all means, go for it. Any energy saving is good.

Let's not forget this thread also includes “Total Home Control and Automation” as part of the title, and that would be difficult to accomplish without a uC. Additionally, this thread is in a forum that is all about microcontrollers, robotics, and automation, so how can we possibly leave them out.


Here is a link to the paper. I have not had time to read it yet so I do not know if it includes the math involved. http://www.eecs.berkeley.edu/~aaswani/proc_brite.pdf

Lots more information available by googling “Learning-Based Model Predictive Control”

Loopy Byteloose
09-25-2011, 10:13 AM
That paper mentions a 'control computer' with link to the internet. So it seems that one would at least have to have a BeagleBoard to provide that portion of the design. Now that I have begun to understand SSH, I suspect a secure Wifi link could be established as well.

I wonder how this would work along with my proposed 'state machine'. Are you always going to allow the computer to predict, or can you override by declaring parameters?

09-25-2011, 10:46 PM
Secure is a relative condition. With enough resources to draw on any encryption can be overcome. For our application any one of the freely available encryption packages should be enough to keep the script kiddies and hacker wannabes at bay. What possible reason would anyone with serious resources have to hack our home automation system?

I would certainly want to have an override. Virtually no software is bug free, and with a complex algorithm there is always the possibility that a bad input or program state would result in an output that could cause some harm.

09-26-2011, 01:50 PM
Lots more information available by googling “Learning-Based Model Predictive Control” .
Now why didn't I think of that! For the internet connection and "control computer" why would the spinnernet not work?

Loopy Byteloose
09-26-2011, 04:22 PM
Lots of things work and the Spinnernet is indeed one of them for an internet connection. Much depends on how much you want to build and how much you want to buy. And what you really want to learn - Spin, Java, Linux, and so forth.

Security is an ongoing process in the computer world. It keeps changing. I prefer to have a hardwire moat with the choice of unplugging the internet it there is a fear or a problem. But others really want their automation to allow them to manage and monitor from afar. So different goals call for different solutions.

Ironically, a dial up modem and Secure Shell protocol via modem might be more secure these days as hackers are not looking for these kinds of openings - they are too busy with new technology.

09-27-2011, 12:29 AM
Ironically, a dial up modem and Secure Shell protocol via modem might be more secure these days as hackers are not looking for these kinds of openings - they are too busy with new technology.

Excellent point. It could also be simpler to implement. Personally I would be looking for some form of remote access and control, but I would be quite happy with a simple text interface.

Loopy Byteloose
09-28-2011, 07:10 AM
Something has been nagging in the back of my mind about a learning computer for home automation and control.

There are really two modes of learning involved.
1. to reconcile goals of the overall home environment
2. to identify and anticipate the needs and wishes of individual occupants.

The second item is interesting in that it requires that the computer identify all the individuals in the home and to keep track of where they are and what they are doing at all a time - but allowing for some privacy.

The learning software provided in the above examples just learns to handle one objective in a very sophisticated manner in real time. I am not sure this is the type of learning that is required.

09-29-2011, 12:26 AM
http://www.ml-class.org/course/auth/welcome I started watching this last night
Stanford machine learning

10-03-2011, 05:31 AM
Here is another home automation and protocol to consider.


It uses RS232 for the hardware level communications but there is no reason something a bit more robust like CANbus or RS485 could be used.

11-19-2011, 10:25 PM
thought this was a good find on the topic of micrcontrollers,digi, and home automation

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&frm=1&source=web&cd=11&ved=0CD0QFjAAOAo&url=http%3A%2F%2Fwww.greentechmedia.com%2Farticles %2Fread%2Fcheap-wifi-thermostats-arrive-at-home-depot%2F&ei=3inJTofVGeTm0QGtitEi&usg=AFQjCNFVtTdhvkgiKfXvaZHMBypJjBYZYg&sig2=vNE1sAq15b4l3iG44wA5Ig