Tellstick Soil Moisture Sensor

This prototype is based on Arduino Uno with a YL-38/YL-69 Soil Moisture Sensor and a FS1000A 433MHz module to send the data to a Tellstick DUO.
Power supply is a 3.7V UltraFire Li-Ion battery in a Power Bank case.

 

This is the final design running on a ATtiny85, powered by a 3.7V Li-Ion AA battery