Question regarding hardware serial and GPIO

Hello,

I am receiving some serial data using HSERIN on a 16F88. I don't need to TX any data. Can I use RB5 (the UART TX pin) as GPIO or is it locked to serial TX function once the SPEN bit is set?

Regards,

Andy

Have you tried disabling TX function and blinking an LED on that pin?

Robert

I have never tried it with a 16F, but with 18F parts I could not make use on the other USART pin when only one was needed. I may have been setting something up wrong though. Best just give it a try.

When you enable SPEN it takes over both pins as you suspected.

Thanks for the replies. The UART TX pin cannot be used fro GPIO in this case.

Andy

From my experience, you can use the TX pin as an input. This same experienced is shared and discussed on the Microchip forum. However, I don't think you should do it if it can be avoided. Again, I have some prototypes which use it that way and they work without issues; but it seems like undocumented (likely unsupported).