Quote Originally Posted by amindzo View Post
Hi,i want to connect two pic microcontrollers (PIC16F873A and PIC16F877A) with serial communication (with serin and serout instructions).there is a long distance between them (40 meter at least).i want to connect them with twist pair shield cable as a connecting cable. maybe we have some errors in transmission,which checksum Algorithm you suggest? what about CRC?
Here are some common methods. Easiest is to sum all of the data into a byte, ignoring the overflow. Another is to xor all of the data. If it is important, you can do both.