This 3d-printable battery powered node allows you to check if your plants need water!
This useful device is based on the MySensors platform and it is built with the new Mini-BT-Pcb board.
The cost of the entire build is low (about 7€) and it use the new type of capacitive soil moisture sensor that have a longer life.
RFM69 (868 Mhz) and NRF24L01 (2.4 Ghz) radio modules are both supported and the behavior of the 4 LEDs can be configured in the firmware.
Visit the dedicated wiki page to build yourself one of this sensor.