The AAduino is an wireless Arduino clone the size of an AA battery with Keystone battery terminals rotated 180° to act as positive and negative terminals. It is meant to go inside a 3xAA battery holder creating a very small wireless node.
Powered by an ATMega328p, it is fitted with an RFM69CW companion, two DS18B20 temperature sensors and an indicator LED.
Included in this repository is the schematics, bill of material and a sample program to test the hardware. If you want solder up one yourself you can buy most of what is needed through the links on the Kitnic page.
If you are looking for an easy way to order the PCBs only, please order from DirtyPCBs.com and I will receive a $1 credit :)
The accompanying blog post is here.