This project upgraded and automated a non-functional motorized monochromator to be used in the optical characterization of semiconductor materials. A monochromator is machine that splits white light into its component wavelengths using a system of mirrors that mimic a prism and isolates a specific band of light for testing. Outdated or non-functional components were replaced with a new power supply, stepper motor, and motor control circuitry. USB communication was implemented to allow users to adjust the output wavelength using simple computer commands. The system was calibrated using a spectrometer to ensure accuracy within ±1 nanometer. The upgraded monochromator reliably produced at least ten visibly distinct wavelengths of light across the visible spectrum.