If you're going to connect some switches on your MuIn USB (using your firmware), you can consider using PORTB since it has integrated pull-up resistors: one pin of the switch will be connected to GND and other pin on PORTB Input. You'll detect the button pressed with some instructions like those: if (!LATBbits.LATBx) // x=0...7 { // instructions to execute if button pressed } else { // instructions to execute if button not pressed ...
Our popular FTDI FT232 based USB->RS232 converter is back in stock!