Supported features

• Snaps on RaspberryPi Zero/3/2
• Supports all DHT11/22/AM2302/BME280 sensors (use appropriate pins and 4.kΩ in R3 if needed). Supports both 3.3V and 5V sensors.
• Dual relay can control 2 independent contacts, like heating thermostat and hot water
• Relays offer both N.C. and N.O. contacts to choose (N.O. contacts used by default)
• Humidity unpopulated contact labelled ‘Humi!’ provide unprotected LOW/HIGH signal @ 3.3V directly from RaspberryPi
• 4×2.5mm holes for securing PCB and RaspberryPi on the case
• User selectable output voltage for the contacts between input supply (default) or 5V
• Additional CPU ventilation holes

Known issues

• Camera connector holder (the part that moves) needs to be removed to allow soldering close to the power supply. Some power supplies have slightly different dimensions and you may need to drill 0.5-1mm further the holes
• Prefer connecting the sensor with wires and place it 4-5cm further to avoid thermal interference from CPU if you plan to enclose this PCB