Founded in 1982, the SRS is one of the oldest and largest robotics groups in the world. Membership is open to everyone. The group holds monthly meetings and several competitions. Encoder online newsletter.

PID-based odometry and dead-reckoning for a mobile robot with differential steering, implemented for a Lego RCX module. Detailed article describes theory of operation. Open Source software written in the NQC language and released under an MIT license.