Our laboratory board supports an RGB LED that can be controlled with a PWM signal. Red, Green and Blue LEDs are in the same enclosure but can be controlled separately. In the stm32duino examples ¹⁾, there is a simple program which allows us to control a single LED. It is named “All-in-one_setPWM” ²⁾. It uses hardware timer output connected directly to an LED. Not every pin can work as the timer output, so this example requires proper selection of the pin connected internally to the PWM timer output. On the laboratory board, the pins used are as presented in table <ref>LEDpinassignment</ref>.