PDA

View Full Version : Another example of a poorly designed battery powered propeller based product



william chan
01-22-2009, 04:18 PM
Can you guess what it is?
Somehow it looks unprofessional, more like a student project.
Any suggestions on how to make the product look more presentable?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Mikerocontroller
01-22-2009, 04:54 PM
It detects motion via the PIR sensor and outputs an IR code produced by the Propeller which modulates the 555 timer operating at 38 khz. If a force great enough to overcome the grip strength of the Velcro is applied, the unit will tip over and activate the mercury switch. By then it is too late and the only thing left to do is run. Looks okay to me but I'm from the Basic Stamp section and have yet to package a project. Your threads are always thought provoking!

Dr_Acula
01-22-2009, 05:03 PM
It is a robot detector. If a human approaches they are detected with the PIR. But if a metallic robot approaches with all the magnets in its motors, it trips the reed switch. The LED is actually a lethal laser. It starts off programmed to zap evil robots but something goes horribly wrong with the code and it gets reprogrammed to zap humans...

Erik Friesen
01-22-2009, 09:05 PM
Polycase will custom cut any of their boxes for you. However you may expect to spend $125+ for a setup fee so you have to be wanting a few of those to pay for that.

william chan
01-22-2009, 10:02 PM
Somehow I think only a custom made case can look commercial. Enclosures are always my weak point.

With the Propeller's surprisingly efficient power design and some smart circuitry, the entire board's average current consumption is only 140 micro amps !.
This is amazing, considering that that Propeller NEVER goes to sleep at all times.

At this current consumption level, I estimate the 2 AA alkaline batteries can last 12 months.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

kwinn
01-22-2009, 10:03 PM
Is it a "one of", a prototype, or a finished product?

Ken Peterson
01-22-2009, 10:07 PM
If I were to guess (which I guess I am..) I would say it detects someone entering the room and then uses the IR LED to turn on the stereo. http://forums.parallax.com/images/smilies/smile.gif

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

william chan
01-22-2009, 10:13 PM
kwinn said...
Is it a "one of", a prototype, or a finished product?


For the 1st batch, we made 10 units for beta-testing.

I am still not satisfied with the outlook, so version 2 will naturally see some changes. (hopefully improvements.)
It is a chicken and egg problem.
We can't finalize the board design unless we can finalize on the casing.
On the other hand, we can't finalize the casing until the board has been finalized!

If we finalize on a board too early, the casing will turn out too bulky or ugly.
If we finalize on a small slim casing, the final board may not fit.

Designing around a good casing is difficult.
Even a simple task of centralizing the PIR sensor to the center of the casing may take days if your PCB is compact.

Anybody facing similar kinds of problem?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Post Edited (william chan) : 1/23/2009 1:55:16 AM GMT

Ken Peterson
01-22-2009, 10:20 PM
That box looks familiar. Is it a case from DAT or backup tape?

I know a lot of people use Altoids boxes.... http://forums.parallax.com/images/smilies/smile.gif

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

StefanL38
01-22-2009, 10:22 PM
Hello William,

do you know a design-university ?

The students need projects to get examined you need a goodlooking case
so come together

Maybe you can initialize a design-contest at a highschool

best regards

Stefan

Fred Hawkins
01-22-2009, 10:32 PM
it's a distributed security sensor, one of (size of your budget or size of the secured area, whichever is less). The sensors yell at each other about the big objects that pass by.

Peter Jakacki
01-22-2009, 10:43 PM
William,

I have used off the shelf cases and dressed them up with laser labels. If you have seen some of my products I have featured on this forum you might like to know that the labels for the prototypes are printed onto heavy duty laser label paper on a color laser. The label is polyester based I believe and resistant to water and oils, tear proof, weather resistant etc. The toner bonds to this very nicely and looks exactly like the real thing. I pick them up at the local office supplies. Try AVERY L7067 for A4 sized sheets or the equivalent. Use OpenOffice Draw to create the labels as it allows precise positioning etc. You would be surprised what a difference a smart label makes.

This is a case I have used with the Prop which has a battery compartment for two AAs plus a window for IR leds.
www1.jaycar.com.au/productView.asp?ID=HB5610&CATID=5&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=644 (http://www1.jaycar.com.au/productView.asp?ID=HB5610&CATID=5&keywords=&SPECIAL=&form=CAT&ProdCodeOnly=&Keyword1=&Keyword2=&pageNumber=&priceMin=&priceMax=&SUBCATID=644)

This case uses a laser label.
http://forums.parallax.com/attachment.php?attachmentid=57690

*Peter*

william chan
01-22-2009, 10:49 PM
Ken Peterson said...
That box looks familiar. Is it a case from DAT or backup tape?


Yes it is. But it is the smaller 150MB or so case, not the larger 400MB case.
Do you know where to buy such cases without buying the DAT tape?

What are Altoids boxes?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Ken Peterson
01-22-2009, 10:55 PM
William: Altoids are mints that come in a small metal box, sold in the U.S. and I'm not sure where else. The box is a popular case for hobby projects.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

william chan
01-22-2009, 11:10 PM
Ken Peterson said...
If I were to guess (which I guess I am..) I would say it detects someone entering the room and then uses the IR LED to turn on the stereo. http://forums.parallax.com/images/smilies/smile.gif


You are so smart.
It is designed to switch on the air conditioner when you enter the room and switch it off when nobody is around for 10 minutes.

Simple but effective energy saving device.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

RDL2004
01-23-2009, 12:42 AM
I doubt the Altoids tin will provide the professional appearance you want.

www.fixup.net/tips/pktamp/original.htm (http://www.fixup.net/tips/pktamp/original.htm)

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
- Rick

Ken Peterson
01-23-2009, 01:28 AM
@RDL2004: I agree. I only mentioned it because it's popular with hobbyists and it may look about as good as a tape case (hence the "grin" in my entry).

If you need something more production-ready, I suggest a project box that screws together. The PCB doesn't necessarily have to fit like a glove.

How you approach this depends on your expected sales volume. Start with an off-the-shelf project box, design your PCB to fit and set up a drilling jig for the holes. Then if you sell enough of those, go to Protomold or some other rapid tooling source and have a custom box made.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

Ken Peterson
01-23-2009, 01:38 AM
Another thought: I suggest using the LQFP-44 package rather than the DIP-40 if you are going into production with it. You can make it much smaller then. Also use the SOIC version of the EEPROM. If your power requirements are really low, perhaps you can also consider a button battery.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

Chris Savage
01-23-2009, 01:42 AM
It appears to have an IR Detector as well. Does this respond to remote control?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Engineering

SRLM
01-23-2009, 02:14 AM
I think it would look more professional if the batteries were mounted on the PCB, and you used all SMD components (that you can at least).

Philldapill
01-23-2009, 02:56 AM
This is really cool, William! When I'm home from school, my dad's always complaining that I leave the AC unit on. Something like this would certainly shut him up! :)

Ken Peterson
01-23-2009, 03:17 AM
@William: I hate to say this in the Propeller forum, but using the Prop may be overkill for this application. You can maximize your profits by using a cheaper microcontroller. Freescale has controllers that will do the job for about $0.50 (US) each, available in an 8-pin SOIC (no external EEPROM required). You may be able to fit the whole thing in the size of a key fob.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

Andrew E Mileski
01-23-2009, 06:16 AM
Dr. Who in Blink said...
This is my Timey-Wimey detector.
Goes ding when there's stuff.
Also, it can boil an egg at thirty paces.
Whether you want it to or not, actually.
I've learned to stay away from hens. It's not pretty when they blow.

Post Edited (Andrew E Mileski) : 1/22/2009 10:22:58 PM GMT

Peter Jakacki
01-23-2009, 06:50 AM
Ken Peterson said...
@William: I hate to say this in the Propeller forum, but using the Prop may be overkill for this application. You can maximize your profits by using a cheaper microcontroller. Freescale has controllers that will do the job for about $0.50 (US) each, available in an 8-pin SOIC (no external EEPROM required). You may be able to fit the whole thing in the size of a key fob.


If you hate to say it then why say it? http://forums.parallax.com/images/smilies/nono.gif

If it's not a Prop then it wouldn't be on this forum and it wouldn't be as much fun either, and neither would we be discussing it. Besides even if you prototype it with a Prop there is still nothing that stops you from doing a production version with something cheaper after you made a functional unit.

However, I have designs which I know I can handle using a cheaper micro but for the sake of a few dollars I choose to use the CPU of my choice, the one that I have abundant tools and software for as well. Besides, I hate debugging conventional micros. If I did a production version of William's cool gadget (I will have to make one myself) then I might look at a small MSP430 mainly for battery life. But then again, as William pointed out the Prop does a surprisingly good job in that department too.

Viva la Prop

*Peter*

william chan
01-23-2009, 06:52 AM
Chris Savage (Parallax) said...
It appears to have an IR Detector as well. Does this respond to remote control?


You have a keen eye for detail...
The IR detector is used to record the equipment's IR pulse train during program mode.
It is powered off to save power during normal operation.

This way, the product can be used for any air conditioner brand.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Post Edited (william chan) : 1/23/2009 4:24:55 AM GMT

william chan
01-23-2009, 07:02 AM
Phil,

I think the coolest thing about this gadget is that it is completely wireless.
Just velcro it near the AirCon and that's it!

SRLM,

I think smaller batteries (button?) cannot handle the IR play current, which is targeted at 80mA (short time) and last one year.
I can't use SMD Prop, because the Prop is the most expensive part in the product.
We only plug in the Prop just before shipping.

Ken,

In a way, you are right, the Propeller is an overkill. I use only 1 cog to save power. Can I get a discount if I use only 1 cog? http://forums.parallax.com/images/smilies/smile.gif
But when viewed in another way, the Propeller is not an overkill, because the SX could not handle this project.

That is why I asked for the TinyPropeller. No battery powered application is going to use 8 cogs.
It's a pity because the Propeller actually has a lot of battery application potential, not many people realize it.

To implement IR record and playback for all air-con brands, I need at least 600 longs (2400 bytes) of ram AND eeprom just for the pulse train storage.
EEProm alone is too slow.

Does the $0.5 Freescale have more than 2400 bytes of RAM?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Post Edited (william chan) : 1/22/2009 11:40:18 PM GMT

william chan
01-23-2009, 08:21 AM
Peter Jakacki said...
Besides even if you prototype it with a Prop there is still nothing that stops you from doing a production version with something cheaper after you made a functional unit.
*Peter*


It would be a pity if the Propeller is only used for prototyping and never for mass production.
How would the price of the Propeller chip come down then?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Ken Peterson
01-23-2009, 08:30 AM
Nobody in their right mind is going to use the Propeller for a production product if it's overkill. I agree with using what you're familiar with for prototype, but if you're in the business to make money, then you use the cheapest thing that will do the job. Leave the Propeller for things that need it.

As to your RAM requirements, there are I2C RAM chips mentioned in other recent posts on this forum that would probably help you there, and you would still be ahead.

Don't get me wrong...I'm a big fan of the Prop, but as an engineer you have to realize that there are more efficient ways to do some things. Business is business.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

Ryan Crabb
01-23-2009, 08:45 AM
Do you plan on selling these? If so will they be offered as a kit? Will you be offering the schematics without the hardware? Will you be releasing the source code?

william chan
01-23-2009, 10:10 AM
No schematics or source code will be released.
PM me for more details.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Philldapill
01-23-2009, 10:13 AM
William, you mention that you would need a boat load of ram to store all the AC brand's codes? I thought this thing "learns" the code? i.e. wouldn't you only need a single long to store THAT code once it's learned?

william chan
01-23-2009, 10:28 AM
Different brand of aircon uses different protocols, so it is not so simple.
On top of that, most aircons send mode, temperature, louver, timer and fan speed in one go when you press the ON button.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

Ken Peterson
01-23-2009, 11:30 AM
I think William is referring to actually digitizing the bit stream from a remote rather than storing the actual codes. This would allow it to learn from any remote, but would use a lot of memory.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

Ryan Crabb
01-23-2009, 01:59 PM
You have an excellent idea. I have no use for it as I have central air in my home. I was hoping to see another open source type product. I can understand completely not releasing any code or schematics. It does take alot time and money to develope a product. Just remember to give back to the propeller comunity. I'm sure you found some example code here usefull in your developement. Good luck and keep us posted on your progress.

Chris Savage
01-24-2009, 01:02 AM
William, very nice. I hope you find a cabinet that you like for your project. I know how difficult that can be to the extend I have built projects (and PCB) around a cabinet I already had.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Chris Savage
Parallax Engineering

Timothy D. Swieter
01-24-2009, 06:37 AM
William - great idea for the air con remote. This type of device could be useful here in Hong Kong since most home have an AC wall unit in each room. I understand your dilema about the PCB design and the case. It sounds like you might have an idea on what size you want, so keep searching and eventually the two paths will meet and you will be able to design a case and a PCB.

So, the reason you can not use an SX is because of the ram size? The reason that ram size is large is because of learning of the IR pulse stream?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Timothy D. Swieter, E.I.
www.brilldea.com (http://www.brilldea.com) - Prop Blade, LED Painter, RGB LEDs, uOLED-IOC, eProto for SunSPOT, BitScope
www.tdswieter.com (http://www.tdswieter.com)

Rayman
01-24-2009, 07:10 AM
Maybe these handheld plastic cases from Hammond would be about the right size for you:

http://www.hammondmfg.com/1553colors.htm

Sparkfun also has a clear plastic enclosure:

http://www.sparkfun.com/commerce/product_info.php?products_id=8632

I'm surprised you can run the Prop for so long with just 2 AAs! But, maybe with no LEDs or display, it's possible...

william chan
01-24-2009, 09:03 AM
Timothy D. Swieter said...

So, the reason you can not use an SX is because of the ram size? The reason that ram size is large is because of learning of the IR pulse stream?


Yes. That is my opinion, but I could be wrong.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

william chan
01-24-2009, 09:35 AM
Rayman,

The blue casing looks nice.
But some of the casing cost more than the propeller!, makes us realize the bargain the prop is.


Rayman said...

I'm surprised you can run the Prop for so long with just 2 AAs! But, maybe with no LEDs or display, it's possible...


Like I said earlier, the Prop's battery capabilities are still a kind of secret to many.

The first prototype PCB uses 800uA and it lasted 1 month.
So I figured the current PCB which uses only 140uA should last 1 year.

The LEDs blink 10ms every 1 second so it's current is negligible.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

mpark
01-24-2009, 10:14 AM
800/140 = 5.7... How do you figure a 12x increase in battery life?

william chan
01-24-2009, 10:48 AM
mpark said...
800/140 = 5.7... How do you figure a 12x increase in battery life?


The mantra is that the less current you use, the more the battery life increases, not linearly but exponentially.

This board actually has a switching boost regulator underneath the Propeller.
When using the boost regulator, the current consumption is 250uA. But the batteries can be used until 0.5v (sum voltage of both cells).
When connected directly without the boost regulator, the current consumption is 140uA, but the batteries can be used only until 2.7v

Which is better?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

mpark
01-24-2009, 11:12 AM
william chan said...

The mantra is that the less current you use, the more the battery life increases, not linearly but exponentially.



Ah, makes sense. Thanks.

Ken Peterson
01-24-2009, 11:44 PM
If RAM capacity is a concern, you can add an external serial RAM quite easily. Many microcontrollers have built-in support for SPI

http://forums.parallax.com/showthread.php?p=778710

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
"I have always wished that my computer would be as easy to use as my telephone. My wish has come true. I no longer know how to use my telephone."

- Bjarne Stroustrup

william chan
01-25-2009, 08:50 AM
I forgot to tell you that there are still some other difficulties presented by this project that only the propeller can handle.

One is to be able to change it's own clock speed.
To play or record the IR, I run the propeller at 40Mhz momentarily.
After that, it runs at 20Khz to keep the RTC, blink some LEDs,
verify the power status of the aircon( in case it is changed by humans using the aircon remote),
detect humans moving around and countdown to switch off the aircon.
The multitude of tasks required means that the Propeller is not allowed to sleep at any time.

I am more familiar with the SX than the Propeller, but the SX can't do this.
Can any Freescale change it's own clock speed?

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.fd.com.my (http://www.fd.com.my)
www.mercedes.com.my (http://www.mercedes.com.my)

mctrivia
01-25-2009, 09:21 AM
the ti 420 day processer would draw less power and have smaller cost. i beleive it runs 20mhz all the time though except when asleep. but it can be woken by clock time so this meens you can artificially slow it down.