The design is pretty simple – an Atmel ATTiny85 microcontroller talks to a DHT22 single-wire temperature+humidity sensor, and transmits readings once every two seconds via the ZigBee protocol. The next step is to design a small PCB to keep everything together. I’m not sure yet if I want to aim for battery-powered or not. I’m more interested in sample frequency than worrying about whether I have enough outlets or extension cords…
In the near future I’ll post schematics and source code, probably at Idle Engineers. Stay tuned!