Motor speed not same, car not moving forward properly

General
1

I was trying the move by code in 2. Move by Code — SunFounder 3in1 Kit documentation the car is turning as both motor not rotating at same speed. Any solution for this?

2
  1. Please make sure your wiring is completely correct yet.
  2. Suggest you provide the problem video to us, easy to analyze and solve the problem.
  3. Please send us your clear wiring diagram.
3

Wiring is correct and its moving as expected. The only issue is rotation speed of motor is a little different which is causing the car to move to one direction. Similar issues are discussed in How to make two motors have really equal speed? - #3 by Abhishek_G - Robotics - Arduino Forum
Now in the example 7. Follow Your Hand — SunFounder 3in1 Kit documentation forward move for both motor is using same speed 150

void moveForward(int speed) {
analogWrite(A_1B, 0);
analogWrite(A_1A, speed);
analogWrite(B_1B, speed);
analogWrite(B_1A, 0);
}

If I change that to 140 for motor A, it improved a little. Is there any other options to get same speed?

void moveForward(int speed) {
analogWrite(A_1B, 0);
analogWrite(A_1A, 140);
analogWrite(B_1B, 150);
analogWrite(B_1A, 0);
}

4

I’m very sorry, there is currently no way to resolve this issue.