LCD issues

Posted: November 24, 2011 | Author: | Filed under: Arduino, LCD display | Tags: , , , | Leave a comment

After running the circulator controller for several days now,  after 4-5 hours, sometimes more, sometimes less the LCD seems to start printing garbage characters.  I have tried several different things to get rid of this but have not done so yet.  My latest attempt to get the program to be stable is to add more delay into the program to allow the LCD more time to work.  After reading the LCD manual it seems that this may be an issue and I will keep my fingers crossed however it appears that this may require a better understanding of the LCD and the programming language requiring a bit more studying.   The Arduino and the program are both running correctly in the background and we are enjoying hot showers, the relays come on and shut off at the correct time, all seems to be working fine with the exception of the LCD display, I have switched out the LCD with another of the same brand and type but I think it must just be getting some bad data and not erasing it.  Any suggestions would be helpful.  Sorry about the picture quality, tough to get a good picture of the display.

Garbled display

Circulator controller now works!

Posted: November 17, 2011 | Author: | Filed under: Arduino | Tags: , , , , , , , | 1 Comment

The Arduino thermostat/circulator controller has now been tested and works, I bought an Adafruit DS1307 RTC and am now displaying the time on a 20x4LCD display.  The relay board has been hooked up and now turns the circulator on or off according the time and temperature.  The circulator pumps hot water from the boiler through the second coil in the solar thermal storage tank to supplement any heat that may be required due to an inadequate solar collection day.   While the electronics now work nicely, the next step will be do put all the components in a neat case so that the project can be finished and mounted.  Let me know if you would like a copy of the code or have any questions.

Arduino thermostat

Posted: October 31, 2011 | Author: | Filed under: Arduino | Tags: , , | Leave a comment

Earlier I finished the piping for the the two additional zones.  A quick recap, one zone will allow  a boiler to heat the tank that is normally heated by solar.  The second zone is really not a zone but the piping and circulator pump that will add heated water from the chip boiler.

The solar water tank, or solar thermal store has two coils in it, the first coil is heated by the solar loop on the roof.  This coil is physically lower in the tank so that the heated water will rise and the sensor controlling this coil is lower as well.  This allows the maximum storage from the tank from solar at all times.  The second coil and sensor that is intended to be heated from the boiler is mounted higher.  The water at the top is  hottest and therefore the  least amount of energy will be needed and the maximum amount of free energy is used first.  Of course solar is not free, it still requires a circulator pump but I assume it to be negligible and therefore in this context free.

Knowing this and assuming that I am going to use an Arduino microcomputer in the process anyway, I am intending to implement the solution in two steps.  The first step to wire and shrink wrap a thermistor  and run the thermistor back to a breadboard, and display the temperature on an LCD.  If the temperature is below a certain value, digital write to a relay to turn on the circulator pump.  If the temperature is good, do nothing.

In the second iteration of the solution my plan is to add a time chip to the system and make the process more efficient.    The logic is this:

8am, no real need for hot water, and there is a good chance the solar will heat the water.

4pm, heat water and maintain until 8pm if needed.

8pm-8am maintain a minimum, lukewarm temp.  We’re not a shower in the morning family.  Of course on the weekend the program will have to be different.

To implement this 2nd iteration a real time chip will be required.  I have found a few, one at sparkfun.com

http://www.sparkfun.com/products/10160, $19.95

 

and a second one at

http://macetech.com/store/index.php?main_page=product_info&cPath=5&products_id=8

I am inclined to the second link, the board is cheaper with a built in battery holder and battery shipped with the product for $14.99

And the yourduino option for $9.00

http://arduino-direct.com/sunshop/index.php?l=product_detail&p=48

http://adafruit.com/products/264

 

Also $9.00

Any opinions?

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