MSP430 Stepper Motor Circuit for the MSP430 microcontroller. Although any MSP430 variant could have been used to implement a basic stepper motor controller using Timer A, the MSP430F123 was chosen since it contains a hardware UART for serial communications with a PC. Two UC3717A integrated circuits (ICs) provide the motor drive circuitry. Each UC3717A IC contains one H-bridge circuit for driving a single winding in a bipolar stepper motor. The UC3717A also contains a chopper circuit limiting the maximum current flowing through a motor's winding
