Click on the link to open the Real Time Counter (RTC) in the MCC Melody API reference for AVR: https://onlinedocs.microchip.com/v2/keyword-lookup?keyword=SCF-AVR8-RTC-V1&version=latest&redirect=true In this video an MCC Melody Project is created, which uses the Event System a pulse is generated on a RTC compare match of 200 ms. The RTC is used to toggle on the RTC overflow every second, using interrupts.