Serial uart communication issues I know this isnt specific but could you suggest some causes for the following issue:

Mega2560 sends values to Raspi 3 and Raspi 3 receives prints them accordingly (arduino also prints out the values it sends). However, at every occasional instances, garbage data is printed on Raspi terminal while the right data is still printed on the serial monitor for Arduino for a baudrate of 115200 for both.

Any helpful suggestions would be appreciated
This answer will also be not so specific, but you can try:


Check all wiring (use a multimeter/analyzer)
Reduce the data rate
Find out if there is a pattern whenever garbage is created (depending on values?)
Check (if possible) for errors (overrun/parity)
Play with the parity setting/stop bits to see if it makes a difference