DataLogger based on Arduino with 434MHz radio and BME280 sensor supplied by 3.6V battery for the transmitter and RaspberryPiZeroW & CC1101 with Python program for receiver.
Controlling the temperature in a 1700 liter aquarium. Heater is a motor valve controlled water radiator via heat exchange.
Weather Station powered with LOLIN ESP8266 and DHT and BMP sensors.