VE9QRP has developed qrpTracker, a satellite tracking program that works on the Arduino platform. Based on the Plan-13 algorithm of James Miller, it can provide real-time satellite location and azimuth / elevation data and doppler shift tuning for up to fifteen satellites using a single ATMega328. With a small additional EEPROM, dozens of satellites can be tracked in real time.
qrpTracker is meant for amateur satellite enthusiasts and computing hobbyists, and its published under the GPL open source license with the code available at Google Code. Further details no this and similar topics can be found at the VE9QRP blog.