Re: Can interrupts be used with USART?
USART communication may well be handled by interrupts.
But you do not tell what PIC device is beeing used, not even which family !!!
The thread is however in: 8-Bit Microcontrollers Forum ...
so unless you are using a obsolete device, then
MPLAB Code Configurator (MCC) can show you how it can be done.
Especially EUSART receiving can benefit from interrupt handling.
And as suggested in message above, keypad scanning may preferably be done in a timer interrupt.