Failed spiral

For this lab, I wanted to create an optical illusion through the movement of the DC motor. I stuck a round shaped piece of stiff paper and tried out several designs. What I wanted was an outward moving spiral and I think my design is right because I can kind of see it when the motor is turning off but otherwise, the motor spins too fast for the effect to be visible to the naked eye. I settled with a design which too demonstrates how perception works and what we see may not be what is.


  • Arduino Uno
  • breadboard
  • 1 DC motor
  • 1 Transistor
  • 1 Diode
  • 1 resistors (one 1KΩ)
  • 1 potentiometer
  • battery pack
  • two AA batteries
  • jumper wires

Arduino Code

* one pot fades one motor and LED

int potPin = A0; // select the input pin for the potentiometer
int motorPin = 9; // select the pin for the Motor
int val; // variable to store the value coming from the sensor
void setup() {
pinMode (potPin, OUTPUT);
void loop() {
val = analogRead(potPin); // read the value from the sensor, between 0 – 1024
analogWrite(motorPin, val/4); // analogWrite can be between 0-255

Leave a Reply