Uses MH-Z19 or MH-Z16 CO2 detector and DHT-22 (or DHT-11) Temperature/Humidity sensor to give air quality readout and actuate relays if CO2 level goes above 1000ppm (Lo Alarm for turning on extraction fan) and High Alarm at 5000ppm to sound an alarm etc. Uses large 20 x 4 HD44780 display
Hardware is 100% Complete. Software is about 90% Complete (Works but untested and buzzer/silence not yet wor...
Time based control for drip irrigation system, with 16x2 LCD (HD44780) for status and configuration.
I designed the board single sided for easy etching at home.
Originaly created using Eagle, and then imported to EasyEDA.