Simple serial communication, legacy or with a USB->serial converter, remains a common interface for microcontrollers. The Bus Pirate uses it, the Arduino uses it, lots of hobby projects rely on a serial data link.
Most Microchip PIC microcontrollers have a UART, hardware that simplifies serial communications. The serial speed is set by programming the baud rate generator register (SPBGR, or similar). Here’s a couple tools we use to calculate the closest BRG value for a given baud rate and PIC crystal speed:
- An SPBRG Calculator spreadsheet
- PIC Baud rate calculator Windows application
- An online SPBRG calculator from piclist
Of course, you can also calculate it by hand, using the formulas in the datasheet.
Use osc 14.7456 and forget errors :-))))