I though the problem was the motors or wheels but I realize the problem is the motor driver because when I change the wires, the another motor run first.
In my case, the motor connected to OUT 1 start one second before the another motor and my robot cannot runs straight.
I hope someone can help me with this problem. I don’t think the driver will be broken because it is new but I am not sure if there are any other electronic stuff can affect the performance of the motors.
I connected two 6vDC Pololu Metal Gearmotor (max current:6A ) to the output terminals powered by rechargeable battery of 7V. In the another side, I connect the INA,INB and PWM1,2, the 2 GND’s and +5 to the microcontroller according to one post that I checked before in this forum.
I hope someone can help me to solve this problem