Through the motor, try to convert electrical energy into mechanical energy…

1.Hook up a servo

Hook up a servo and make it move using pwm.

// Chapter 5 - Motor Control
// Controlling Speed
// By Cornel Amariei for Packt Publishing

// Include the Servo library
#include <Servo.h> 

// Declare the Servo pin
int servoPin = 3;
// Create a servo object
Servo Servo1;

void setup() {
  // We need to attach the servo to the used pin number
  Servo1.attach(servoPin);
}

void loop(){
  // Make servo go to 0 degrees
  Servo1.write(0);
  delay(1000);
  // Make servo go to 45 degrees
  Servo1.write(90);
  delay(1000);
  // Make servo go to 90 degrees
  Servo1.write(360);
  delay(1000);
}

2.Hook up a motor

Motor can convert the signal into mechanical power, help us drive the external mechanical device.

const int switchPin = 2;
const int motorPin = 9;
int switchState = 0;
void setup() {
  pinMode(motorPin, OUTPUT);
  pinMode(switchPin, INPUT);
}
void loop(){
  switchState = digitalRead(switchPin);
  if(switchState == HIGH) {
    digitalWrite(motorPin, HIGH);
  }
  else {
    digitalWrite(motorPin, LOW);
  }
}

3.Hook up an MPR121

Create a circuit I control with a touch sensor.

The touch sensor is so sensitive that it detects different values, like operating a touch screen to output values.