This is still a work in progress, but is definitely functional. I am posting this instructable so others can both build their own smart thermostats, and hopefully build on this project with their Climaduino improvements.
Here are the features so far:
- temperature and humidity sensors
- Relay to control A/C
- LCD Display
- Buttons to control temperature
- Controls both temperature and humidity
- Settings stored in EEPROM and survive power failures
- Short cycle protection for efficiency and compressor protection
- Raspberry Pi-based
- Mobile-optimized web interface to control Climaduino settings
- Historical temperature and humidity graphs
- Programmable temperature and humidity changes
Why did I want to build this? Mainly because it was fun to do and I've always been very interested in climate control. (I know that sounds weird, but it's true.) It's also because humidity is a huge issue in my area, South Florida. I designed the Climaduino Thermostat to take this into account. The A/C will stay on just a little bit longer when it's humid to wring more moisture out of the air. I also added a humidity control mode. It can save a significant amount of power and prevent coming home to a mold-infested house. Humidity control mode ignores temperature and only runs the A/C when things get too humid. It's useful when going out of town or when the house is empty (of people and pets).
If you perform any of the steps in this instructable, you assume all risk for the outcome. Working with high voltage can be extremely dangerous. Improperly altering your A/C unit could lead it to malfunction or completely break. Please be careful.
Electrical Safety: Safety and Health for Electrical Trades Student Manual