       switch (leftMode) {
         // left motor forward
         case FORWARD:
-          analogWrite(PIN_MOTOR_LEFT_A, 0);
-          analogWrite(PIN_MOTOR_LEFT_B, leftPWM);
+          analogWrite(PIN_MOTOR_LEFT_A, leftPWM);
+          analogWrite(PIN_MOTOR_LEFT_B, 0);
           break;
 
         // left motor brake

      switch (rightMode) {
        // right motor forward
        case FORWARD:
          analogWrite(PIN_MOTOR_RIGHT_A, 0);
          analogWrite(PIN_MOTOR_RIGHT_B, rightPWM);
          break;

        // right motor brake


        // right motor reverse
        case REVERSE:
          analogWrite(PIN_MOTOR_RIGHT_A, 0);
          analogWrite(PIN_MOTOR_RIGHT_B, rightPWM);
          break;
      }
    }
