Assignment 09

Arduino controlled Silly String shooter


Due Wednesday, October 31: Use a 9V battery to create a standalone (i.e. not connected to the computer) Halloween prop. It can be part of a costume, or a modification of a commercially available decoration (if you wish). It should be spoooky!

Shoot a video of the object in action; post it on YouTube and embed it in a blog post with the category Assignment-09.

  • It should have at least one input: buttons, potentiometer, sensors….
  • It should have some kind of output: LEDs and/or servo, etc. etc.
  • It should work without a computer attached. Program the Arduino, unplug the USB and plug the 9V cable. You can press the tiny reset button to restart the program.
  • You can use alligator clips or wire extensions to separate Arduino + board from sensors and actuators.
  • You can check the examples in the manual, like the DC motor…
  • LEDs themselves are not that exciting, but you can use all sorts of objects to diffuse their light ping-pong balls, balloons, pumpkins…

Code Example:
Light sensor controlled twitchy servo. Servo twitches randomly when it gets dark.

#include <Servo.h> 
Servo servo1;
int pos1 = 0;
int period = 500;
int sensorValue = 0;
unsigned long lastDidItTime = 0;

void setup() { 
  servo1.attach(3);  // attaches the servo on pin 3 to the servo object 

void loop() {
  sensorValue = analogRead(A0);
  unsigned long presentTime = millis();
  if(sensorValue < 90){  // if it's dark...
    unsigned long elapsedAmount = presentTime - lastDidItTime;
    if (elapsedAmount > period){  // do something spooky
      pos1 = random (0, 180); 
      lastDidItTime = presentTime;

Posted in