With the advent of high-speed digital signal processors (DSPs) specialized for motion control applications, it has become possible to control motors without mechanical (speed or position) sensors. This application report presents a low-cost, sensorless drive system for a switched reluctance motor (SRM) based on the TI’s TMS320F243 DSP. Detailed descriptions of the hardware configuration, the sensorless commutation algorithm, its implementation details, and procedures for measuring motor parameters should enable readers to rapidly duplicate and customize a sensorless SRM drive system to meet their specific application.