Wireless sensor for embroidery.
The sensor is a tilt-compensated compass i.e. a 3D accelerometer in combo with a 3D magnetometer. Compared to my other wireless boxes, this one runs on 3.0V (two AAA batteries) and not 3.6V. This due to the LSM303DLH sensor's lack of onboard voltage regulators and 1.8V I2C data lines.
The ATmega168 has an Arduino sketch loaded as firmware and is using the internal 8 MHz oscillator. So the circuit is pretty minimal.
As part of the project knyppel with Ann Rosén. Also, see this post.
Schematics, Arduino firmware, parts list, MaxMSPJitter patches, SuperCollider class attached.