Electronic + Coding 1

Vibrator Schematic + Code

DataSheet Transistor
DataSheet PowerConverter
int signalPin = 3;  // PWM Pin
int strength = 0;

void setup()
{
  // init the pwm pin as output
  pinMode(signalPin, OUTPUT);
}

void loop()
{
  analogWrite(signalPin, strength++);
  delay(20);

  if(strength > 255)
    strength = 0;
}