so i'm sitting here trying to think about how to lay out the data that i want on my lcd display... and this is what i've come up with so far.. suggestions are requested...
·
starting top left, thats collector input temp, colector output temp, heat exchanger input, heat exchanger output, and then top right is tank temp
I was also thinking about having it display the current time, or maybe some kind of tracking information.. the other thought would be to have it display the kW from the system, once i have a flowmeter...
The other thought was to mount the display behind a bezel, and just have the data on the screen and then have the labels off the lcd, that way i can display more data and not be using up my lcd space for the labels...
The #### is space holders for something like 135.7 just without the decmil
well my prop and sensors and stuff came in last night, a day early, what a surprise..
so now its time to get busy.. since i got the usb board to make my life easier, i was thinking that theres just not enough prototyping space on that board, so i was thinking that i could just solder in some wires to all the pins i neec access to and run them over to one of my breadboards.· anyone got any better ideas?· maybe a picture of what you did?·
I figure once i get everything all wired up and working for the final product, i can then draw up and etch myself a nice pcb and get everything off the breadboards, but for now, i guess thats about the best i can do.
one thing that i'm not sure of right now is which holes are connected to what.· I know that the row around the prop chip on the board is labeled, so thoes are easy, but are any of the other holes connected to thoes, or anything else?· I guess what i mean is on some proto boards, every row of 5 is connected together, is this board the same way?
Thoughts?
something else that i've been thinking about for this project, is to use a stepper motor to run the pump to circulate the heat transfer fluid.· so what i would need from the prop is a pulse train, 50% duty, at around 66.6hz(if i use direct drive to the pump, if i geared it say 2:1 then i would want 133Hz, and i would want to vary the freq out dependant on a couple factors.·
The pulses would go to a stepper driver, that only needs direction and speed, well the direction would be fixed, so i could hard wire that outside the prop.· Then the pulses from the prop would tell the controller advance the stepper motor one step per pulse.· I would want to use one of my temp measurements to vary the pump speed, so as temp increased, pump speed would as well.
The other thing that i would want to use this for, is to use the pulses(or the count of them) to calculate the volume of fluid moved.· the pump moves a specific amount per revolution, so at 20rpm, the pump moves 1 gallon per min.· Then take that information, have the prop do some math, and have it display the btu transfer rate on the lcd.
how do i even go about starting something like this?· I have the stepper driver already built, and stepper motors are easy enough to get my hands on...
Post Edited (Project5k) : 1/29/2009 3:25:52 PM GMT
There is a PDF on the site that shows all the connections on the Proto board. No, they aren't connected in rows like some proto boards.
Why do you want to vary the speed of the pump? As long as the pump moves enough water to prevent boiling on your hottest day, you are OK. There is no benefit heat gain-wise by moving the water slower on cooler days.
I just run my pumps and then use a stopwatch and and fill a container for a minute then measure the amount of water. This will allow you to calculate BTU's, which I'm guessing is what you are looking for. For fun, calculate how much electricity it would take to create the same amount of BTU's. It will shock you, my system can create the equivilant of a 12kW electric heater. Of course, the "real" GPM will change when you connect it to the rest of the plumbing, but it will get you in the ballpark. You would need a flow sensor to get an exact GPM under real conditions.
Steppers to drive a pump sounds like a lot of extra trouble, with no real gain and in fact less effecient, electricity-wise.
Jonathan
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
I forgot to add, you can indeed solder wires for use with a breadboard. When you get to your final stage, look into SIP headers, that's what I do. My solar hit tub controller doesn't use a protoboard, it's a DIP, so a pic of mine wouldn't help.
Jonathan
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔ www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
yea, headers and flat cables would probably be a better long term solution. so i guess all of the pins that i'll need to access are the ones that are already labeled on the board...
I am starting a project that is very similar. I intend to use the Propeller to control mirrors for a solar concentrator. I cannot find any follow up to this thread which seemed to be on the right tract.Is there any progress postings?
Hi Project5k;
You mentioned you wanted a "Heliostat".
You have not been describing a heliostat.
You have been describing a "Direct Solar Tracker". I.e. aiming directly at the sun.
This is what I wrote on my webpage: http://www.redrok.com/main.htm#definitions
HELIOSTAT or CENTRAL RECEIVER SYSTEM:
1. A heliostat is, generally, a two axis solar tracking flat mirror that reflects sunlight onto a fixed receiver or target.
2. Furthermore, the geometry between the Sun, Mirror, and Receiver are constantly changing throughout the day.
3. In general the mirror is aimed normal to the bisector between the sun and receiver.
Many mistakenly call "Direct Solar Trackers", such as Dishes, Troughs, and Lenses heliostats. They are not.
Generally, these things are aimed directly at the Sun which violates #2 above.
I am specifically interested in a heliostat with a series of stepper motor controlled mirrors aimed at a target receiver. I have found a very accurate algorithm for calculating sun and target position posted by the National Energy Research Laboratory in Golden , CO. The reference provides source code written in C++ which I am hoping to adapt to PropBasic and compile to Spin. The complex algorithm may be too much for a Propeller but I think the Propeller chip may at least enable the mirror stepper control on multiple reflectors even if I have to crunch the numbers on a separate micro and communicate the targeting information to the Propeller. I have looked at solar parabolic concentrators but the mechanics of multiple focus points makes my application too cumbersome. First estimates are roughly 10 m^2 reflective surface generating a potential of 10kw solar radiation. I am hopeful of around 20% efficiency or better to yield approximately 2 1/2 - 3 hp of usable power. Using a concept originally patented by Einstein, this amount of power should enable air conditioning equivalent to our central air conditioner. I intend to start small with a simple parabolic concentrator tracking the sun but when I can get the tracking right I will scale up to the heliostat concept. So far I am thinking steppers (with power down capability) will be easier to control than servos as their position can be known without feedback loops provided there is sufficient mechanical advantage. I live on the Gulf coast which has similar solar radiation to southern California and our air conditioning costs are huge (approaching $900/month in the middle of summer). If I can provide even a 1/4 of our A/C needs I can pay for this project in a matter of a couple of years. I can camouflage multiple small mirrors in our residential community better than a single large dish. I am fully aware of the Analemma challenge but it seems that with the power of 8 cogs the complexities can be overcome one step at a time (no pun intended).
hi all, sorry for falling off the face of the earth there for a while, but i'm back, and i'm going full strength at this solar water heater project... i have a propellor chip in house, and i have the flat plate solar collector plumbed in and working now as we speak... i'm just manually controlling the pump for now..
getting back on track, i have learned a few things, and have changed my goals a little bit..
List of goals:
measure and log
temperature of:
the collector output at the collector itself
temp of main water heater top and bottom
temps of the 2 pre heat tanks 1 each
temp of the solar loop tank
temp of the in comming ground water
possibly in the future a flow meter with 1 pulse per gallon
solar strength or brightness?
so thats 7 temp inputs, a brightness, and one for a flow meter...
display all data, in F, along with a few calculated values....
have the ability to put unit into override mode, lock pump on or off and things like that...
perhaps use a small peizo element for alarm stuff...
in the future, what about adding an east west sepperator, have 2 collectors, one east for morning, and one west for afternoon, and a valve of some sort so that which ever is doing better is the one that the pump pushes water to...
also seriously considering running the HX loops sepperate from the collector loop(s) this would require an additional pump output...
also need to have a thermal dump... this is easy mechanically, just requires another pump....
hardware i have in house...
#27979 4x20 serial backlit lcd
#27937 memory stick datalogger
#32812 prop proto usb board
1 wall wort power supply out 7.5v 1A
2 vt900 photoconductive cells
6 lm34 temp sensors....
1 tlc2543cn 12 bit ADC w/11ch
2 20W 110vAC pumps
1 300W 110vAC pump
loads of random electronics, relays, proto boards, resistors, and stuff...
I'm working on a couple basic drawings to illustrate the system... and also a logic diagram, cause i know i'm gonna need that when i get to the programming stage....
more to come... just trying to get all my thoughts organized....
input?
so just a short update, i was playing around with the parts, and i now have one of the lm34's on the output of the collector, so i can use a volt meter and read it from inside the house... also have the board and lcd connected and can make text display on the lcd... its progress....
going to frys this afternoon and will be looking to get some header pins and things to make connecting to the board easier... also ... i found a couple things for trying to make the tlc2543 work with the prop, i found some .spin things, but i havent found any solid schematics for the connection yet... looking at the sheets for each, its looking to me like i can get away with 5 connections between the prop and the adc... question becomes, at what point do i need to sepperate the power supplys of the prop, and then external circuitry? i have to drive the lm34's with something, and i'm not thinking that thoes, and the external relays that i'm gonna use to control the pumps and things like that are all gonna be powered by the prop board.. its only got a 300ma supply.....
on the data logger, or usb stick interface, it looks pretty straight fwd, i have schemats for that...
I have solar hot water heater on my house which I’d like to improve the efficiency. Presently, cold water comes into a hot water heater that is designed for solar. It’s a insulated tank with 220v heating elements that kick on approx. 105 deg F. The tank has connections for a 120v circulating pump. The pump draws from the bottom, pumps up to the panels, back down into the tank thru a check valve – it’s not a closed loop, the heated water is mixed with the water in the tank. The check valve is there to stop the flow of hot water back up to the panels at night. The pump is controlled by a module from http://www.butlersunsolutions.com/ which has manuals and other tech info. The module has a high setting limit that shuts the pump off when the tank temperature reaches the high temp – no further heating occurs. Then there is a differential setting which starts the pump when the panel temp is greater than a few degrees of the tank temp. It all works great except I’d like to improve on it. One improvement is to eliminate the check valve, because it leaks back hot water to the panels. I’d replace it with a solenoid or zone valve – all check valves leak to some degree. I’d also like to add a 3 way valve on the cold water inlet. On cloudy days when there’s insufficient sun to heat all the tank, I’d like to at least pre heat the incoming cold water. Cold water would be diverted to the panels then to the tank when hot water is demanded. Even though I would still be heating the water electrically, it would be preheated to some degree by the panels. Also, Id like to cutout the electric elements during the morning after taking a shower. The tank would be heated up by solar later in the day while the sun is overhead. If it’s a cloudy day the elements would kick on to provide hotwater in the evening. I live on Kauai so the sun is plentiful, but the electric rates are high, so it pays to get as much BTU’s out of the sun. Something to consider is freeze protection if you're in a cold climate.
you might like solarpowerforum.net if your not allready familiar... i'm on there as well...
I'm having a real hard time finding information on how to make the TLC2543 talk to my prop... I did find a couple things, the "lm34_sensorDemo" but i'm having no luck getting it working in my situation... i've changed the pins, so i'm getting something from the adc, but the only output i get on the display is 255.. which i'm thinking is the base setting for the adc's output.. but i dont have any kind of a data line to cary data from the prop to the adc, cause that code there just has provisions for input, not output...
does anyone have any suggestions? i'm getting really discouraged at the lack of information... do i need to just order a different ADC? theres one that i see everywhere, um... MCP3208... thats still 12 bit, not that i really think that i need all 12 bits, but hey, why not... would it just be easier to change horses mid stream? hehehe
Here is a small program snippet written in FemtoBasic that uses a pair of
Blue LEDs as solar light sensors.
The schematic is here: http://www.redrok.com/images/LEDBluePropA1.png
Blue LEDs generate enough voltage to directly drive Propeller inputs.
In the example I used pins 14 and 15.
The LEDs operate as current sources to charge the capacitor. The LED
with the greater light wins and impresses its polarity onto the capacitor.
The rate of charging is dependent on the light flux and the size of the capacitor.
In this case I used .1uF
There is a FOR NEXT statement that determines how much time it takes to
charge the capacitor. Reducing the capacitor increases the sensitivity.
PRINT SOLAR TRACKER
NEW
90 OUTA [27..0] = 0
100 B = 0 : D = 0 : G = 0 : P = 14
210 FOR T = 0 TO $FF
220 A = INA [P+1..P]
230 IF (A & 1) = 1 THEN B = B + 1
240 IF (A & 2) = 2 THEN D = D + 1
280 NEXT T
310 OUTA [P+1..P] = 0
320 PRINT "" : S = D : C = 2 : GOSUB 7000
330 IF D > B THEN DISPLAY 62 ;
340 IF D = B THEN DISPLAY 32 ;
350 IF D < B THEN DISPLAY 60 ;
360 S = B : C = 2 : GOSUB 7000
370 REM PRINT ""
810 GOTO 100
7000 REM Print a HEX Number
7001 REM Pass C = # of Printed Characters, Value Unaffected
7002 REM Pass S = the Number to be Printed, Value Unaffected
7003 REM Pass G = Comma Flag, Value is comma placement Value Unaffected
7004 REM U = Scratch Variable
7005 REM V = Scratch Variable
7010 REM PRINT "$" ; : REM Possibly done in the calling routine
7020 FOR V = (C // 9) TO 1 STEP -1
7030 U = ((S REV (V * 4)) REV 4) + 48
7040 IF U > 57 THEN U = U + 7
7050 DISPLAY U ;
7060 IF G <> 0 THEN IF ((V-1) // G = 0) & (V<>1) THEN PRINT "," ;
7070 NEXT V
7190 RETURN
RUN
I've been away and busy redoing my plumbing so I will have an "attic solar water heating system". That is I will run pipes in the attic to collect heat and circulate that heat to my hot water heater tank. There is a LOT of heat in my attic during the summer...
Anyway I am planning on building my own controller for all this, so I am VERY INTERESTED in this topic as I will be doing the same things. And will probably be using a Propeller for this.
Perhaps I could be of some help?
What I was planning on doing was to start out simple at first. That is just have two heat sensors and a circulation pump. Then get the circulation pump to turn on when the water temperature in the attic was warmer than that in the hot water heater tank.
And that was all I was planning to do at first. Just get that one thing working. And I can envision all sorts of problems relating to just that (such as rapid cycling of the pump).
Then add a display and other features later once that was working.
I've had a lot of success with other complex projects in the past by just concentrating on one thing at a time. Getting that to work, then working on the next feature.
So what specifically are you trying to do and what is the trouble? Do you have any one thing working?
I can understand your frustration. In addition to being an interesting project, it seems involved so success might be harder to come by than first hoped. One of the beauties of the prop is the ability to break a project into parts. Solve one part, then set it aside and solve another. When combined back together in the final version those parts need not mess one another up. What I'm suggesting is to break this down into the simplest individual projects you can. Once each component project is working, set it aside and solve another. When all the component have been proven individually, start brining them into a unified project.
I haven't worked much with LCDs, but when I did I still found Prop Serial Terminal invaluable as a place to dump debug messages. I'd start there. Get the LM34 working with a serial terminal. Treat the LCD as a component until you are sure it works the way you want it to. At this point I'd treat it as a component and not use it for debugging. I know you've already amassed parts, but for temp sensors I don't think it gets much simpler than the Maxim/Dallas DS18B20 series. They provide a digital out and therefore don't require and ADC. They use a 1-wire bus so you can connect as many as you want to the same Prop Pin and talk to them individually, and there's an object in the OBEX for reading them. And they only require a single pull-up resistor to work.
I wish you luck on this as it looks fun and useful.
Project5K
I like your idea and has given me the idea to do something for the the ship that I am restoring the Zuni/Tamaroa, but, in a small scale.
I don't know, if know this or not. But, you my need mixing vavles, that alound the cold water to mix with the hot water. This helps control the temps and pervents you from being burned. You may also want to get proportional vavles to control the water temps and can be controlled with the propeller using analog singals like 0-5vdc, 0-10vdc, or 4-20mA.
As what pgbpsu stated. I wish you luck on this as well
well i have the lcd working, i can put in stuff in the programmer, and make it display stuff on the screen and blink and clear, and display text in time with blinking LED's, simple stuff like that that i was able to just figure out by cutting and pasting from some of the "lessons" i found online...
really my biggest issue right now is trying to figure out how to get my TLC2543 to talk to my prop... i found one thing in the xchange, but it didnt work correctly... could be the wireing... i'm not 100% sure how to wire the 2 together... i have a prop proto usb that i've added headers to so i can use my big proto board, and i've also stuck the lcd in a little holder, just so its not just floppn round on the desk...
as for the DS18B20... well, i wish i had known about thoes before i had gone and bought the adc and lm34's that i have now.. hmmm.. just one question, the information that i read said that it was celcius, now i'm figuring that i could just do a conversion in the prop, but is there a F version, would it matter??? cuz theres a f version of the lm34, and then theres the lm35 thats the C version.. so, just wondering how bigga deal that would be...i just know i'm not gonna be happy if its not in F...
for now, this system is going to just be a preheat system, so i wont have to worry about being burned...
I briefly looked through all the above. It looks like you are wanting to interface the LM34 to the Propeller. You can "cheat"! That is search google.com images for the terms lm34 schematic. Then this will find all sorts of circuit diagrams using the LM34!
@Project5k- I understand your frustration about TLC2543. I realize there may be an element of pride and really wanting to get what you've got working. But before you dedicate yourself to that course of action (which is a worthy one that has a great deal of satisfaction once solved), might I suggest the Dallas/Maxim DS18B20 again. If you search the maxim/dallas site you can find the TO92 package as a free sample. It wants a pull up resistor (4.7K I think) at the minimum.
Then go to the OBEX and get one of the objects already written to talk to it. I think the one from Micah Dowty works. I don't know if it includes a temp in degrees F, but that's a simple conversion. There is a Float Object in the OBEX that will allow you to do floating point math in the conversion. (Multiply degrees C by 1.8 and add 32).
If you do choose the DS18B20, I can help. I've used them before. The TLC2543 I've never used.
thanks so much for the input, the more i read, and the more i think about it, i think the smart course is to abandon the 2543 for now... its a good chip(working) but just not within my scope of understanding at this time... i'll save it for later.. once i have a better grasp of SPIN and the prop itself, i may come back to it and figure it out... and yes, i will share my findings if i have anything worth sharing
reading the ds18b20 data sheets now...
ok, samples ordered...
looking in the obex, i'm not finding anything i thnk is right... search returns nothing for the 18b20... found Micah's name, ... the closest i could find was "1-wire routines in spin" dl'd that one... never know...
did i just overlook it?
as for interfacing the lm34's to the prop, i think i'll save thoes for some simpler fan control circuits and other things, oh, a temp controller for the fish tank.. or maybe just some simple thermometers for the living room... I've seen the circuits for doing direct through a couple resistors, and stuff, and i just really dont have the tight tollerance parts"resistors" that it would require to be consistant across several sensors...
with the digital output of the 18b20 i can allways just factor in a correction factor in the prop math for each sensor should i figure out that its needed... you know, allways +2 for sensor 1 and -1 for sensor 2 or whatever....
I think those are the right routines but I've attached a couple that I've used in the past. I normally set them up with power, ground, and signal pin. You can do parasitic power, but I've not tried that. The OneWireTest.spin file has a bunch of stuff you don't need, but it should be useful for testing that you got it connected correctly and it's responding. I think it also has the C->F conversion in it. You'll need the SpinOneWire.spin file as well.
I hope these help. Don't forget the PullUP resistor.
I'm gone for a couple of weeks so hopefully you'll have this worked out before I return, but if not I can help you when I get back.
i'm gonna go ahead and do mine with an external v supply too, gonna need it else where in the circuit, so might as well...
this is awesome... well as soon as the samples come in i'll be back at it... sick today, so my brain just isnt up to speed to learn anything today...
thanks for the files, i did have the spinone, but not the onewire....
and thanks for letting me know to not expect a reply for a bit... i'll update the thread as i go, and when you get back you can see where i'm at...
yes please, any help would be much appreceiated... i really think that once i kinda get a start, and get a little bit of a feel for the programming, i'll be able to handle the large parts, i mean looks like i'm gonna be able to copy and paste the big parts anyway, so a few lines, and a few tweaks... who knows... but i'm sure there'll be more q's...
i would love to have this done and working before you get back, and have some data to show for it... hehehe i cant wait till i get it all working and logging data...
I found getting the one-wire temp sensors working the first time a bit tricky, but once I figured it out (I kept okay notes about setup) they have been pretty easy to use in other projects. They may not be the least expensive temp sensors on the market (although free samples are hard to beat), but they are stable and allow you to have multiple sensors and only use on prop pin. They all use the same code so you just need an array large enough to hold all the address (=2*number of devices because addresses are 64-bit).
Best of luck. Use the files as sent as much or as little as you want. Those work for me but no guarantees there aren't any bugs. I look forward to seeing where you've got to when I return.
alrighty, time to get to it... samples came in today... so, i'll be looking at this spin stuff some more, and seeing if i can get the temp sensors reading and displaying on the lcd.... wish me luck!
i havent made much progress with this so far, i've been spending most of my time getting all the hardware set up.. I'm now collecting heat from the sun and storing it in the tanks...
now i gotta start controlling this system a little more intelligently than just on at 9am and off at 5pm... so...
i have my prop, and proto board, and lcd set up from before.... time to get code'n
I have a stamp1. All I want to do is turn on a pump when there is a temperature differential of say 20 degrees between, two temperature sensors. Simple is good, I have very limited experience.
Comments
·
starting top left, thats collector input temp, colector output temp, heat exchanger input, heat exchanger output, and then top right is tank temp
I was also thinking about having it display the current time, or maybe some kind of tracking information.. the other thought would be to have it display the kW from the system, once i have a flowmeter...
The other thought was to mount the display behind a bezel, and just have the data on the screen and then have the labels off the lcd, that way i can display more data and not be using up my lcd space for the labels...
The #### is space holders for something like 135.7 just without the decmil
so now its time to get busy.. since i got the usb board to make my life easier, i was thinking that theres just not enough prototyping space on that board, so i was thinking that i could just solder in some wires to all the pins i neec access to and run them over to one of my breadboards.· anyone got any better ideas?· maybe a picture of what you did?·
I figure once i get everything all wired up and working for the final product, i can then draw up and etch myself a nice pcb and get everything off the breadboards, but for now, i guess thats about the best i can do.
one thing that i'm not sure of right now is which holes are connected to what.· I know that the row around the prop chip on the board is labeled, so thoes are easy, but are any of the other holes connected to thoes, or anything else?· I guess what i mean is on some proto boards, every row of 5 is connected together, is this board the same way?
Thoughts?
something else that i've been thinking about for this project, is to use a stepper motor to run the pump to circulate the heat transfer fluid.· so what i would need from the prop is a pulse train, 50% duty, at around 66.6hz(if i use direct drive to the pump, if i geared it say 2:1 then i would want 133Hz, and i would want to vary the freq out dependant on a couple factors.·
The pulses would go to a stepper driver, that only needs direction and speed, well the direction would be fixed, so i could hard wire that outside the prop.· Then the pulses from the prop would tell the controller advance the stepper motor one step per pulse.· I would want to use one of my temp measurements to vary the pump speed, so as temp increased, pump speed would as well.
The other thing that i would want to use this for, is to use the pulses(or the count of them) to calculate the volume of fluid moved.· the pump moves a specific amount per revolution, so at 20rpm, the pump moves 1 gallon per min.· Then take that information, have the prop do some math, and have it display the btu transfer rate on the lcd.
how do i even go about starting something like this?· I have the stepper driver already built, and stepper motors are easy enough to get my hands on...
Post Edited (Project5k) : 1/29/2009 3:25:52 PM GMT
There is a PDF on the site that shows all the connections on the Proto board. No, they aren't connected in rows like some proto boards.
Why do you want to vary the speed of the pump? As long as the pump moves enough water to prevent boiling on your hottest day, you are OK. There is no benefit heat gain-wise by moving the water slower on cooler days.
I just run my pumps and then use a stopwatch and and fill a container for a minute then measure the amount of water. This will allow you to calculate BTU's, which I'm guessing is what you are looking for. For fun, calculate how much electricity it would take to create the same amount of BTU's. It will shock you, my system can create the equivilant of a 12kW electric heater. Of course, the "real" GPM will change when you connect it to the rest of the plumbing, but it will get you in the ballpark. You would need a flow sensor to get an exact GPM under real conditions.
Steppers to drive a pump sounds like a lot of extra trouble, with no real gain and in fact less effecient, electricity-wise.
Jonathan
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
I forgot to add, you can indeed solder wires for use with a breadboard. When you get to your final stage, look into SIP headers, that's what I do. My solar hit tub controller doesn't use a protoboard, it's a DIP, so a pic of mine wouldn't help.
Jonathan
▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
www.madlabs.info - Home of the Hydrogen Fuel Cell Robot
You mentioned you wanted a "Heliostat".
You have not been describing a heliostat.
You have been describing a "Direct Solar Tracker". I.e. aiming directly at the sun.
This is what I wrote on my webpage:
http://www.redrok.com/main.htm#definitions
HELIOSTAT or CENTRAL RECEIVER SYSTEM:
1. A heliostat is, generally, a two axis solar tracking flat mirror that reflects sunlight onto a fixed receiver or target.
2. Furthermore, the geometry between the Sun, Mirror, and Receiver are constantly changing throughout the day.
3. In general the mirror is aimed normal to the bisector between the sun and receiver.
Many mistakenly call "Direct Solar Trackers", such as Dishes, Troughs, and Lenses heliostats. They are not.
Generally, these things are aimed directly at the Sun which violates #2 above.
Duane
getting back on track, i have learned a few things, and have changed my goals a little bit..
List of goals:
measure and log
temperature of:
the collector output at the collector itself
temp of main water heater top and bottom
temps of the 2 pre heat tanks 1 each
temp of the solar loop tank
temp of the in comming ground water
possibly in the future a flow meter with 1 pulse per gallon
solar strength or brightness?
so thats 7 temp inputs, a brightness, and one for a flow meter...
display all data, in F, along with a few calculated values....
have the ability to put unit into override mode, lock pump on or off and things like that...
perhaps use a small peizo element for alarm stuff...
in the future, what about adding an east west sepperator, have 2 collectors, one east for morning, and one west for afternoon, and a valve of some sort so that which ever is doing better is the one that the pump pushes water to...
also seriously considering running the HX loops sepperate from the collector loop(s) this would require an additional pump output...
also need to have a thermal dump... this is easy mechanically, just requires another pump....
hardware i have in house...
#27979 4x20 serial backlit lcd
#27937 memory stick datalogger
#32812 prop proto usb board
1 wall wort power supply out 7.5v 1A
2 vt900 photoconductive cells
6 lm34 temp sensors....
1 tlc2543cn 12 bit ADC w/11ch
2 20W 110vAC pumps
1 300W 110vAC pump
loads of random electronics, relays, proto boards, resistors, and stuff...
I'm working on a couple basic drawings to illustrate the system... and also a logic diagram, cause i know i'm gonna need that when i get to the programming stage....
more to come... just trying to get all my thoughts organized....
input?
going to frys this afternoon and will be looking to get some header pins and things to make connecting to the board easier... also ... i found a couple things for trying to make the tlc2543 work with the prop, i found some .spin things, but i havent found any solid schematics for the connection yet... looking at the sheets for each, its looking to me like i can get away with 5 connections between the prop and the adc... question becomes, at what point do i need to sepperate the power supplys of the prop, and then external circuitry? i have to drive the lm34's with something, and i'm not thinking that thoes, and the external relays that i'm gonna use to control the pumps and things like that are all gonna be powered by the prop board.. its only got a 300ma supply.....
on the data logger, or usb stick interface, it looks pretty straight fwd, i have schemats for that...
I'm having a real hard time finding information on how to make the TLC2543 talk to my prop... I did find a couple things, the "lm34_sensorDemo" but i'm having no luck getting it working in my situation... i've changed the pins, so i'm getting something from the adc, but the only output i get on the display is 255.. which i'm thinking is the base setting for the adc's output.. but i dont have any kind of a data line to cary data from the prop to the adc, cause that code there just has provisions for input, not output...
does anyone have any suggestions? i'm getting really discouraged at the lack of information... do i need to just order a different ADC? theres one that i see everywhere, um... MCP3208... thats still 12 bit, not that i really think that i need all 12 bits, but hey, why not... would it just be easier to change horses mid stream? hehehe
Here is a small program snippet written in FemtoBasic that uses a pair of
Blue LEDs as solar light sensors.
The schematic is here:
http://www.redrok.com/images/LEDBluePropA1.png
Blue LEDs generate enough voltage to directly drive Propeller inputs.
In the example I used pins 14 and 15.
The LEDs operate as current sources to charge the capacitor. The LED
with the greater light wins and impresses its polarity onto the capacitor.
The rate of charging is dependent on the light flux and the size of the capacitor.
In this case I used .1uF
There is a FOR NEXT statement that determines how much time it takes to
charge the capacitor. Reducing the capacitor increases the sensitivity.
See other circuits that operate on the same principal:
http://www.redrok.com/electron.htm#ledblue
PRINT SOLAR TRACKER
NEW
90 OUTA [27..0] = 0
100 B = 0 : D = 0 : G = 0 : P = 14
210 FOR T = 0 TO $FF
220 A = INA [P+1..P]
230 IF (A & 1) = 1 THEN B = B + 1
240 IF (A & 2) = 2 THEN D = D + 1
280 NEXT T
310 OUTA [P+1..P] = 0
320 PRINT "" : S = D : C = 2 : GOSUB 7000
330 IF D > B THEN DISPLAY 62 ;
340 IF D = B THEN DISPLAY 32 ;
350 IF D < B THEN DISPLAY 60 ;
360 S = B : C = 2 : GOSUB 7000
370 REM PRINT ""
810 GOTO 100
7000 REM Print a HEX Number
7001 REM Pass C = # of Printed Characters, Value Unaffected
7002 REM Pass S = the Number to be Printed, Value Unaffected
7003 REM Pass G = Comma Flag, Value is comma placement Value Unaffected
7004 REM U = Scratch Variable
7005 REM V = Scratch Variable
7010 REM PRINT "$" ; : REM Possibly done in the calling routine
7020 FOR V = (C // 9) TO 1 STEP -1
7030 U = ((S REV (V * 4)) REV 4) + 48
7040 IF U > 57 THEN U = U + 7
7050 DISPLAY U ;
7060 IF G <> 0 THEN IF ((V-1) // G = 0) & (V<>1) THEN PRINT "," ;
7070 NEXT V
7190 RETURN
RUN
I've been away and busy redoing my plumbing so I will have an "attic solar water heating system". That is I will run pipes in the attic to collect heat and circulate that heat to my hot water heater tank. There is a LOT of heat in my attic during the summer...
Anyway I am planning on building my own controller for all this, so I am VERY INTERESTED in this topic as I will be doing the same things. And will probably be using a Propeller for this.
Perhaps I could be of some help?
What I was planning on doing was to start out simple at first. That is just have two heat sensors and a circulation pump. Then get the circulation pump to turn on when the water temperature in the attic was warmer than that in the hot water heater tank.
And that was all I was planning to do at first. Just get that one thing working. And I can envision all sorts of problems relating to just that (such as rapid cycling of the pump).
Then add a display and other features later once that was working.
I've had a lot of success with other complex projects in the past by just concentrating on one thing at a time. Getting that to work, then working on the next feature.
So what specifically are you trying to do and what is the trouble? Do you have any one thing working?
I can understand your frustration. In addition to being an interesting project, it seems involved so success might be harder to come by than first hoped. One of the beauties of the prop is the ability to break a project into parts. Solve one part, then set it aside and solve another. When combined back together in the final version those parts need not mess one another up. What I'm suggesting is to break this down into the simplest individual projects you can. Once each component project is working, set it aside and solve another. When all the component have been proven individually, start brining them into a unified project.
I haven't worked much with LCDs, but when I did I still found Prop Serial Terminal invaluable as a place to dump debug messages. I'd start there. Get the LM34 working with a serial terminal. Treat the LCD as a component until you are sure it works the way you want it to. At this point I'd treat it as a component and not use it for debugging. I know you've already amassed parts, but for temp sensors I don't think it gets much simpler than the Maxim/Dallas DS18B20 series. They provide a digital out and therefore don't require and ADC. They use a 1-wire bus so you can connect as many as you want to the same Prop Pin and talk to them individually, and there's an object in the OBEX for reading them. And they only require a single pull-up resistor to work.
I wish you luck on this as it looks fun and useful.
Regards,
Peter
I like your idea and has given me the idea to do something for the the ship that I am restoring the Zuni/Tamaroa, but, in a small scale.
I don't know, if know this or not. But, you my need mixing vavles, that alound the cold water to mix with the hot water. This helps control the temps and pervents you from being burned. You may also want to get proportional vavles to control the water temps and can be controlled with the propeller using analog singals like 0-5vdc, 0-10vdc, or 4-20mA.
As what pgbpsu stated. I wish you luck on this as well
really my biggest issue right now is trying to figure out how to get my TLC2543 to talk to my prop... i found one thing in the xchange, but it didnt work correctly... could be the wireing... i'm not 100% sure how to wire the 2 together... i have a prop proto usb that i've added headers to so i can use my big proto board, and i've also stuck the lcd in a little holder, just so its not just floppn round on the desk...
as for the DS18B20... well, i wish i had known about thoes before i had gone and bought the adc and lm34's that i have now.. hmmm.. just one question, the information that i read said that it was celcius, now i'm figuring that i could just do a conversion in the prop, but is there a F version, would it matter??? cuz theres a f version of the lm34, and then theres the lm35 thats the C version.. so, just wondering how bigga deal that would be...i just know i'm not gonna be happy if its not in F...
for now, this system is going to just be a preheat system, so i wont have to worry about being burned...
the solar part of the project is online here: http://www.solarpowerforum.net/forumVB/do-yourself-discuss-your-projects/5279-im-back-im-serious.html
I briefly looked through all the above. It looks like you are wanting to interface the LM34 to the Propeller. You can "cheat"! That is search google.com images for the terms lm34 schematic. Then this will find all sorts of circuit diagrams using the LM34!
And perhaps you might find something easier. Here is that search...
(If you find something interesting, click on the image, then "Website for this image". You might get lucky and find circuit diagrams along with explanations of how everything works.)
http://www.google.com/images?hl=en&sugexp=ldymls&xhr=t&q=lm34+schematic&cp=7&safe=off&bav=on.1,or.&wrapid=tljp129830679571806&um=1&ie=UTF-8&source=og&sa=N&tab=wi&biw=771&bih=439
http://www.maxim-ic.com/datasheet/index.mvp/id/2812/t/or
Then go to the OBEX and get one of the objects already written to talk to it. I think the one from Micah Dowty works. I don't know if it includes a temp in degrees F, but that's a simple conversion. There is a Float Object in the OBEX that will allow you to do floating point math in the conversion. (Multiply degrees C by 1.8 and add 32).
If you do choose the DS18B20, I can help. I've used them before. The TLC2543 I've never used.
Best of luck.
Peter
reading the ds18b20 data sheets now...
ok, samples ordered...
looking in the obex, i'm not finding anything i thnk is right... search returns nothing for the 18b20... found Micah's name, ... the closest i could find was "1-wire routines in spin" dl'd that one... never know...
did i just overlook it?
as for interfacing the lm34's to the prop, i think i'll save thoes for some simpler fan control circuits and other things, oh, a temp controller for the fish tank.. or maybe just some simple thermometers for the living room... I've seen the circuits for doing direct through a couple resistors, and stuff, and i just really dont have the tight tollerance parts"resistors" that it would require to be consistant across several sensors...
with the digital output of the 18b20 i can allways just factor in a correction factor in the prop math for each sensor should i figure out that its needed... you know, allways +2 for sensor 1 and -1 for sensor 2 or whatever....
I hope these help. Don't forget the PullUP resistor.
I'm gone for a couple of weeks so hopefully you'll have this worked out before I return, but if not I can help you when I get back.
this is awesome... well as soon as the samples come in i'll be back at it... sick today, so my brain just isnt up to speed to learn anything today...
thanks for the files, i did have the spinone, but not the onewire....
and thanks for letting me know to not expect a reply for a bit... i'll update the thread as i go, and when you get back you can see where i'm at...
yes please, any help would be much appreceiated... i really think that once i kinda get a start, and get a little bit of a feel for the programming, i'll be able to handle the large parts, i mean looks like i'm gonna be able to copy and paste the big parts anyway, so a few lines, and a few tweaks... who knows... but i'm sure there'll be more q's...
i would love to have this done and working before you get back, and have some data to show for it... hehehe i cant wait till i get it all working and logging data...
Best of luck. Use the files as sent as much or as little as you want. Those work for me but no guarantees there aren't any bugs. I look forward to seeing where you've got to when I return.
Peter
now i gotta start controlling this system a little more intelligently than just on at 9am and off at 5pm... so...
i have my prop, and proto board, and lcd set up from before.... time to get code'n
Cool, very cool!
Excellent job!