So I am working on an experimental rover. It has 4 DC motors for the 4 wheels and a dedicated Arduino mega shield circuit for controlling the navigation of the rover only. I am using BTS7960 motor drivers for driving the motors. The Arduino is connected to the motor driver through an optocoupler isolating the two parts. There is no encoder involved and we used a radio receiver only. Both the Arduino and the motors are powered with separate power sources.
At first I used a power bank circuit which uses LiPo batteries to power the Arduino mega using the USB. But the Arduino randomly resets itself (checked using an oscilloscope for further confirmation). We also used a buck module at a higher voltage level (7V) using the barrel connector to power the Arduino. Still the problem persists. But when we used a Raspberry pi 4 to power the Arduino, the problem is solved. We have tested with this configuration for a long time and did not face any issues like that. But any other configuration the problem shows again. But using a raspberry pi is not really a viable option for us in the long term. Also we still cannot narrow down the problem nor find any solution.
Also I would like to add that we experienced EMI from the motors which was interfering with our receiver but we managed to solve that. Maybe that EMI is also contributing to these random resets but still we cant understand why powering the Arduino with a raspberry does not show the problem. There is another circuit for controlling a 5 DOF arm which also consists of DC motors for some parts but it does not randomly resets itself even when powering the Arduino with the power bank circuit.