I'll go just one more step.

Don't try to invert your data, and also, don't try to un-invert your data. It is correct the way it is.

 

That is a good rule to keep in mind. The UART feature in AVR and PIC microcontrollers are designed to transmit and receive the correct polarity over an RS232 link when a TTL to RS232 converter is used to produce the correct RS232 signal levels.

hgmjr

 

Well my oscilloscope broke today. I have no idea how I am going to get a replacement.

But, I discarded the uart library and did the serial port manually and lo and behold: it worked!

I am never using the MCC18 libraries again. They always screw up.

Thanks for all your help.