dc water pump speed control using arduino

dc-water-pump-speed-control.ino

/**
 * receive command from serial and contorl motor speed by setting pwm duty
 */
// motor A Control pins (output 1,ouptut 2)
#define IN1 5
#define IN2 6
#define ENA 3

void setup() {
  pinMode(IN1,OUTPUT);
  pinMode(IN2,OUTPUT);
  pinMode(ENA,OUTPUT);
  // put the motor in forward direction
  digitalWrite(IN1,HIGH);
  digitalWrite(IN2,LOW);
  // set default speed
  analogWrite(ENA,100);
  Serial.begin(115200);
}

void loop() {
  if (Serial.available()) {
        String inputString = Serial.readStringUntil('\n');
        if(inputString.startsWith(":")){
          String sliderValueStr = inputString.substring(1); // extract the angle
          int sliderValue = strtol(sliderValueStr.c_str(), NULL, 10); // convert str to int
          Serial.print("Received angle set cmd ");
          Serial.println(sliderValue);
          analogWrite(ENA,map(sliderValue, 0, 180, 0, 255));
        }
    }
}