Could hack the Toro Xtra Smart Wireless Soil Sensor. It uses the Atmel AT86RF212 900MHz RF chip and costs $45 on eBay (including receiver that contains a PIC and a relay so it can act as a rain sensor for a traditional irrigation controller).
Could hack the Toro Xtra Smart Wireless Soil Sensor. It uses the Atmel AT86RF212 900MHz RF chip and costs $45 on eBay (including receiver that contains a PIC and a relay so it can act as a rain sensor for a traditional irrigation controller).