Hi menta,

Any type of software timed commands like SERIN/OUT, OWIN/OUT, PAUSE, PULSIN/OUT etc, will be disturbed by these types of Interrupts.

That's why there's an ON INTERRUPT GOTO statement. It reverses the situation, so that the PAUSE, SERIN/OUT etc trash the Interrupts instead, which seems more tolerable to people new to PBP, but just drove me crazy. And is why I ended up with DT_INTS.

With Interrupts, you need to use HARDWARE solutions instead of the SOFTWARE timed commands, and in your case the 16F887 has a USART on-board that is NOT affected by interrupts.

So just switch over to HSEROUT, and your problems will vanish.

DT