The objective of this project was to develop an embedded system for monitoring and controlling a pulse-width-modulated (PWM) signal. This signal was to be generated by an externally connected NE555 Timer module. Connected to the timer was a 4N35 Optocoupler that would be the driving force for generating the correct PWM signal. In order to control the 4N35 Optocoupler, the microcontroller on the STMF0 Discovery board was to measure an input potentiometer voltage value and pass it as an output to the optocoupler.

Effectively, the microcontroller should read the potentiometer’s voltage, pass it to the 4N35 Optocoupler, then read the generated frequency of the incoming PWM signal from the NE555 Timer. Furthermore, the microcontroller needed to output the potentiometer’s resistance and the NE555 Timer’s PWM frequency to a liquid crystal display (LCD) module in real time.