Simple PWM Generation using Serial Interface for a Circulation Pump used in Solar Water Heaters

The aim of this work is to create a PWM generation application for a Wilo-Yonos PICO pump used in a solar water heater. The solar system uses solar panels to heats water in water tanks. The water tanks are connected with pipes of different diameters. To make circulation of water a Wilo-Yonos PICO pump is used. This pump is controlled with a PWM signal. The PWM signal must be generated as simple and as cheap as possible. The chosen method was to control a simple PWM signal generator via serial interface, this way generating the required PWM signal.