LN298 does not work forwards but it does work backwards

Projects General Guidance
1

I use an Arduino Mega, with a LN298 motor controller

I have 4 engines.

My problem is that an engine does not work when it should go forward, but, curiously, it does work when it should go backward. That is, it is not a connection problem, change the LN298 board and the problem continues, change the arduino pin and the problem continues, I think it is because of the code, I don't know, but it is something very basic, high and low.

My code is the following:

#include <Wire.h>


// Motor A
int ENA = 13;
int IN1 = 12;
int IN2 = 11;
// Motor B
int IN3 = 10;
int IN4 = 9;
int ENB = 8;
// Motor A1
int ENA1 = 7;
int IN11 = 6;
int IN21 = 5;
// Motor B1
int IN31 = 4;
int IN41 = 3;
int ENB1 = 2;

const byte numChars = 32;
char receivedChars[numChars];
boolean newData = false;

void setup() {

  Serial.begin(115200);
  Serial.setTimeout(0);

  // Indicaciones para el control
  Serial.println("Velocidad 255 max. - 128 medio - 0 min.");
  Serial.println("Adelante - 1");
  Serial.println("Atrás - 2");
  Serial.println("Derecha adelante - 3");
  Serial.println("Izquierda adelante - 4");
  Serial.println("Derecha atrás - 5");
  Serial.println("Izquierda atrás - 6");
  Serial.println("Parar - 7");
  Serial.println("Servo 1 - 8");
  Serial.println("Servo 2 - 9");
  Serial.println("Voltage - a");
  Serial.println("Gyro, Accel - b");

  // Declaramos todos los pines para los motores 0
  pinMode (ENA, OUTPUT);
  pinMode (ENB, OUTPUT);
  pinMode (IN1, OUTPUT);
  pinMode (IN2, OUTPUT);
  pinMode (IN3, OUTPUT);
  pinMode (IN4, OUTPUT);
  // Declaramos todos los pines para los motores 1
  pinMode (ENA1, OUTPUT);
  pinMode (ENB1, OUTPUT);
  pinMode (IN11, OUTPUT);
  pinMode (IN21, OUTPUT);
  pinMode (IN31, OUTPUT);
  pinMode (IN41, OUTPUT);


}

void loop() {
  recvWithEndMarker();
  arduinoControl();
}

void recvWithEndMarker() {
  static byte ndx = 0;
  char endMarker = '\n';
  char rc;
  while (Serial.available() > 0 && newData == false) {
    rc = Serial.read();
    if (rc != endMarker) {
      receivedChars[ndx] = rc;
      ndx++;
      if (ndx >= numChars) {
        ndx = numChars - 1;
      }
    }
    else {
      receivedChars[ndx] = '\0';
      ndx = 0;
      newData = true;
    }
  }
}

void arduinoControl() {
  if (newData == true) {
    
    // Adelante
    if (receivedChars[0] == '1') {
      Serial.println("Adelante");
      Serial.println(atoi(&receivedChars[2]));

      //Direccion motor A
      digitalWrite (IN1, HIGH);
      digitalWrite (IN2, LOW);
      analogWrite (ENA, atoi(&receivedChars[2])); //Velocidad motor A

      //Direccion motor B
      digitalWrite (IN3, HIGH);
      digitalWrite (IN4, LOW);
      analogWrite (ENB, atoi(&receivedChars[2])); //Velocidad motor B
      
      //Direccion motor A 1
      digitalWrite (IN11, LOW);
      digitalWrite (IN21, HIGH);
      analogWrite (ENA1, atoi(&receivedChars[2])); //Velocidad motor A 1
 
      //Direccion motor B 1
      digitalWrite (IN31, LOW);
      digitalWrite (IN41, HIGH);
      analogWrite (ENB1, atoi(&receivedChars[2])); //Velocidad motor B 1
      
    }

    // Atrás
    else if (receivedChars[0] == '2') {
      Serial.println("Atrás");
      Serial.println(atoi(&receivedChars[2]));

      //Direccion motor A
      digitalWrite (IN1, LOW);
      digitalWrite (IN2, HIGH);
      analogWrite (ENA, atoi(&receivedChars[2])); //Velocidad motor A

      //Direccion motor B
      digitalWrite (IN3, LOW);
      digitalWrite (IN4, HIGH);
      analogWrite (ENB, atoi(&receivedChars[2])); //Velocidad motor B
      
      //Direccion motor A 1
      digitalWrite (IN11, HIGH);
      digitalWrite (IN21, LOW);
      analogWrite (ENA1, atoi(&receivedChars[2])); //Velocidad motor A 1

      //Direccion motor B 1
      digitalWrite (IN31, HIGH);
      digitalWrite (IN41, LOW);
      analogWrite (ENB1, atoi(&receivedChars[2])); //Velocidad motor B 1
      
    }


    // Parar
    else if (receivedChars[0] == '7') {
      Serial.println("Parar");
      Serial.println(atoi(&receivedChars[2]));

      //Direccion motor A
      digitalWrite (IN1, LOW);
      digitalWrite (IN2, LOW);
      analogWrite (ENA, 0); //Velocidad motor A

      //Direccion motor B
      digitalWrite (IN3, LOW);
      digitalWrite (IN4, LOW);
      analogWrite (ENB, 0); //Velocidad motor B
      
      //Direccion motor A1
      digitalWrite (IN11, LOW);
      digitalWrite (IN21, LOW);
      analogWrite (ENA1, 0); //Velocidad motor A1

      //Direccion motor B1
      digitalWrite (IN31, LOW);
      digitalWrite (IN41, LOW);
      analogWrite (ENB1, 0); //Velocidad motor B1
    }

    newData = false;
  }
}

The problem is in:

 //Direccion motor B
      digitalWrite (IN3, HIGH);
      digitalWrite (IN4, LOW);
      analogWrite (ENB, atoi(&receivedChars[2])); //Velocidad motor B
2

Please post the schematics. Don't use Fritzing.

2 Likes
3

Hi
change the motor.

4

Hi,
Can i suggest you write some simple code to make your motor run back and forwards, to see if you have the correct sequence to control the motor?

If you wrote this code in stages, at what stage did you not have proper control?

Tom... :grinning: :+1: :coffee: :australia:

1 Like
5

Is it possible to only use digital signals to control a motor? Because with ESP32 I am having problems with analog signals. It only works in one direction.

6

This topic was automatically closed 180 days after the last reply. New replies are no longer allowed.