Basic Stamp 2 for residential climate control via PC

Derek22

I have an old basic stamp 2 kit which I would like to use for home climate control. While I have experience in control, I have forgotten everything I knew about the basic stamp. In banging the internet, I remain unsure if it is capable of reporting sensor readings to the pc. At the least, I need to get the data to the pc for analysis. Also of course, I will be using relays to control the heat, cool, and fan contacts for the thermostat.
I am finding documentation very sketchy. I have lost the documentation I received with the stamp.
If it is impractical to maintain bidirectional data between the stamp and the pc, are there suggestions for a different route? Money is definitely an object.

Thank you all
Derek

Unsoundcode

Hi Derek , what you ask is completely feasible , a good staring point is PLX-DAQ located at this link http://www.parallax.com/tabid/441/Default.aspx is capable of logging your data for use in a spreadsheet.

Jeff T.

Derek22

Thanks Jeff, I'll let you know what I find
Derek

Manetheren

There are many different examples on here for a simple visual basic program that you can create yourself to show the data that the stamp collects. I think i found some HVAC control for the basic stamp at some point also. You would need to combine them together or find a different control program to use like the X10 control program. (just search for x10 and many different threads come up.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tia'Shar Manetheren

Derek22

Ok, Jeff that looks good as far as the data analysis goes. I guess I'll tell you a little bit about my project. I intend to use the cheapest equipment possible to implement a control strategy to reduce energy consumption while maintaining tolerable enthalpy inside the home. I intend to monitor the following:
outside temp/humidity
inside temp/humidity
supply air temp/humidity
return air temp/humidity
evaporator temp
compressor current
fan current
current to the main breaker in the home

I intend to strategically operate the compressor at times of maximum efficiency, such as at night, to reduce indoor humidity and "store cool" using the thermal inertia inside the home. I will study the results of this to determine what steps to take after this test.

I would like to hear ideas regarding how to keep costs down on the sensors in particular, as I am trying for a low cost solution that is within the grasp of people with little money who are the most needy of reduced energy costs.

I would also like to hear ideas regarding the use of wireless sensors.

Regarding the current sensors, I would prefer current sensors that are easy to clip on to wiring in the breaker box and a/c unit.

Also, has anyone seen threads discussing this idea before? It seems it should be getting very popular nowadays with energy costs so high and the destruction of our environment being accelerated by our current means of energy production.

Thanks
Derek

Derek22

Thanks for the idea, Tai
I wonder what the cost comparison would be between the hardware necessary to implement the x10 solution versus a wireless solution.

Unsoundcode

Hi Derek , there are a lot of discussions on·those same topics here on the forums .

In case you did not know when you search the forums use this search engine http://search.parallax.com/

Jeff T.

Manetheren

I have been trying to figure out a cheaper method of cooling my bedroom at night as I sleep better when it is colder, but dont want to cool the whole house or buy a big compressor for just one room. I have also been looking at the X10 control method and this seems like a cheaper way to control things witht he use of a stamp if you can get them cheap enough through E-bay or Overstock. The main webcite has them way too much.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tia'Shar Manetheren

Manetheren

If you found a way to have the stored cold/hot liquid, then individual room cooling/heating might be cheaper due to the energy required for a smaller room than a whole house.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tia'Shar Manetheren

WBA Consulting

For your temp/humidity readings, the Sensirion SHT11 sensor would be the ideal solution. This may not meet your inexpensive concept depending on where your desired dollar amount is being set. These sensors are very small, accurate, and have a simple to use interface. Here are some links to look at:

Parallax 28018 Sensirion Module

Thread for my SHT11 module
My Module page with examples and code links

Tracy Allen's web page on usage of the SHT11 sensor

You could also look at pairing a DS1620 Digital temp sensor and the HS1101 Humidity Sensor to save costs. This humidity sensor can be setup with a 555 timer so you can just read the frequency output to guage humidity. The 555 timer circuit is on page 3 of the datasheet. The DS1620 is pretty straightforward.

You could easily place the HS1101 humidity sensor at each of your locations, then use one of the SHT11 sensors to "validate" the readings/values to increase the accuracy of your final setup. I did this for a stainless steel thermistor probe for my polar bear plunge datalogger. I could read the value with RCTime but had no idea how to convert that to a true resistance for the temperature. By comparing readings between the thermistor and the SHT11, I created a simple chart of values for the range I was looking for. Not perfectly accurate, but accomplished my goal.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Andrew Williams
WBA Consulting

Derek22

HI, Tia
Regarding cooling just one room, I bought the smallest window unit I could find, it only draws 8 amps. That is about half of what a space heater draws. To put the energy cost in perspective, a space heater uses about 1.5 kw. If you were to run a space heater 24/7, and your cost per kilowatt hour is around the average of 10 cents, then the space heater will cost you about $120 per month to run.
Conversely, if you ran the window unit like that your cost would be half that. Since the compressor doesn't run all the time, your cost is even less.
Regarding the store cool technology, that is a great idea I like as well. For this project though, I am thinking of using the thermal inertia inside the home because it is free, and if the solution is not very cheap, most people will never implement it.

Derek

Derek22

Hi, Andrew
Thanks for the info and links. I looked at the SHT11 on your website and it looks good, though I could not find pricing. I will let you know what I find when I finish investigating the links you sent me. My experience has been with industrial equipment which uses 0-5V, 4-20mA, or relay contacts for sensors. I guess I need to find a good tutorial on the basic stamp to see how it uses RC timing and clock to implement sensor readings.

Derek