No data received through serial bus

I currently am trying to have the openmv camera gather data and send to my arduino end using the uart serial. I think on the openmv side everything looks correct but I’m probably missing something on the arduino end. Nothing is being printed in the serial monitor, this is my code:

void setup(){
void loop(){
if (Serial1.available()){
byte byteRead =;

Arduino code is right, could be wire connections or the OpenMV Cam code.

Please note, what you posted is not enough for anyone to actually help you. Nor… should you be doing multiprocessor interfacing and don’t have deep experience debugging and have access to a logic analyzer.

Could it be my pins? I have the P5 and P4 OpenMV pins connected to TX1 18 and RX1 19 Arduino Mega pins respectively.

I also have a wire that goes ground to ground.

I actually just changed my pins so that they use UART 3, so TX3 14 with P4, and RX3 15 with P5. Still, my serial monitor does not display any data.

RX has to go to TX and TX to RX. Did you do this?

Uh i don’t really know. is P4 RX or TX?

P4 is TX, P5 is RX.