Adding an MCU to control the KVM switch is one of the Todo lists. This weekend I just finish the concept by wiring up all the stuff with an MCU EVT board. The MCU I choose is CH32V003F4P6( a 32-bit RISC-V MCU running at 48MHz, more detail here). 

With the help of the MCU, the KVM switch can be controlled by the PiKVM web UI or the manual switch button, the web UI can also indicate which pc is active in the meantime. In the next version, I'll add 2 LEDs on the PCB to indicate the active PC too.

The PCB file that combines the KVM switch and the MCU into one PCB board was finished. Hopefully, I will get the PCB from the factory next week. I'll post an update at that time.