Programming the Continuous Motor Circuit with a Potentiomete

 /*
  *  Jung Min Yean
  *  Learning HBridge Motor Control
  *  04/23/2019
  */

const int MotorPin = 9;
const int MC1 = 3; //Motor Control 1 direction
const int MC2 = 2; //Motor Control other direction
const int PotPin = A0;

int val = 0; // for storing the reading from the Pot.
int velocity = 0; //For stroing the desired velocity (from 0 - 255)

void setup()
{
  pinMode(MotorPin, OUTPUT);
  pinMode(MC1, OUTPUT);
  pinMode(MC2, OUTPUT);
  pinMode(PotPin, INPUT);
  brake(); // Initialize w/ motor stopped
}

void loop()
{
  val = analogRead(PotPin);

  // go forward
  if (val > 550)
  {
    velocity = map(val, 550, 1023, 0, 255);
    forward(velocity);
  }

  // go backward
  else if (val < 500)
  {
    velocity = map(val, 500, 0, 0, 255);
    backward(velocity);
  }
  // brake is needed between 500 - 550 to change direction
  else
  {
    brake();
  }
}

// Motor goes forward at given Motor rate (from 0 - 255)
void forward(int rate)
{
  digitalWrite(MotorPin, LOW);
  digitalWrite(MC1, HIGH);
  digitalWrite(MC2, LOW);
  analogWrite(MotorPin, rate);
}

// Motor goes backward at given Motor rate (from 0 - 255)
void backward(int rate)
{
  digitalWrite(MotorPin, LOW);
  digitalWrite(MC1, LOW);
  digitalWrite(MC2, HIGH);
  analogWrite(MotorPin, rate);
}

void brake()
{
  digitalWrite(MotorPin, LOW);
  digitalWrite(MC1, LOW);
  digitalWrite(MC2, LOW);
  analogWrite(MotorPin, HIGH);
}