Quote Originally Posted by Charles Linquis View Post
115Kbaud with a 4MHz XTAL is tough. Because the divisor has to be an integer, you can get only within 3.55% of the exact baud rate. That error is probably a bit too much. Look at the datasheet table 18-3.

20Mhz works much better. That gives you a 1.36% error. Small enough to work well.
In this case, set BRGH = 1 and SPBRG = 10
what about 16Mhz XTAL