DC Motor PWM control with a potentiometer and L298N

In this video I show you a simple example of controlling a DC motor by using an Arduino and a L298N dual H-bridge circuit. By transforming the values of the potentiometer to values on the PWM output you can control the speed of you DC motor.

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Wiring diagram

The L298N is used only in 1 direction mode in this particular example. The demo only shows the PWM control through reading the value of a potentiometer.

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Arduino source code

int potPin = 0;                    // select the input pin for the potentiometer (A0)
int val = 0;                       // variable to store the value coming from the sensor
char receivedCommand;              // character for controlling the serial program
//---------------Motor
const int pinA = 8;               //Enable (Power)
const int enA = 5;                //Enable (PWM) '~'
//-------------------
bool runningEnabled = false;
bool newData = false;
 
 
void setup()
{
  pinMode(pinA, OUTPUT);
  pinMode(enA, OUTPUT);
  Serial.begin(9600);  
  Serial.println("DC-MOT-POT");
}
 
void loop()
{
readSerialPort();  
readPotmeter();
}
 
void readSerialPort()
{
  if (Serial.available() > 0) //is there a data on the serial?
     {
        receivedCommand = Serial.read();
        newData = true; //if we received a new command we set this bool to true
     }
     
     if (newData == true)
     {
          if(receivedCommand == 's') //Start
            {
              runningEnabled = true; //start = enable running
            }
         
          if(receivedCommand == 'n')//Stop
            {
              runningEnabled = false; //shut down everything
              digitalWrite(pinA, LOW);
            }
      }
        newData = false;  //reset newData to false so we can receive new command
 
}
 
void readPotmeter()
{
  if(runningEnabled == true) //is running is enabled?
  {
    val = analogRead(potPin);    // read the value from the pot (A0)
    val = map(val, 0, 1023, 0, 255); //map 0-1023 to 0-255 ; |-----------| ---> |------|
    analogWrite(enA, val); //write PWM (pin ~5)
    digitalWrite(pinA, HIGH); //enable power
    Serial.println(val); //print on serial
  }
  else
  { //do nothing, disable power if it was enabled previously
    runningEnabled = false;
    digitalWrite(pinA, LOW);
  }
}

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