Ghost Projector

by littleBits

Published on April 23, 2014

'Come with us', two small ghostly figures beckon. As you draw closer you hear a rattling sound. The figures suddenly quadruple in size and appear very close to you. Run away!!!

Perfect your haunted house on Halloween with this spooky and surprising project.

How To Make It


Let's start by building the circuit. Connect these Bits Modules in the following order: power + motion trigger + wire + bright LED + wire + vibration motor + inverter + pulse + wire + bright LED.

Note: the motion trigger is very sensitive. It senses your movement in up to a 10ft radius. You may want to try and decrease the sensitivity by trying some of these Motion Trigger Tips & Tricks (http://littlebits.cc/fridays-tips-tricks-the-motion-trigger)


Understand the circuit! You will notice that the second half of the circuit (after the inverter) is on when you turn the power on. This is because the inverter sends out the opposite message from what it receives. So, when the motion trigger in the first half of the circuit is not activated, the second half of the circuit is receiving an "on" signal (the second bright led will be pulsing). However, when you make a movement, you activate the motion trigger which sends an "on" signal to the first LED and vibration motor. When this happens, the inverter sends an "off" signal to the latter half of the circuit.


Print out (or draw) 2 spooky images on transparency paper. Then play around with placing the images in front of the bright LEDS and facing them towards a light colored wall. You will notice that the image on the transparency paper is now projected onto the wall.


Play with angles. We positioned our images so that when they switch from one image to the other, they shine in the same place. When the first half of our circuit is "on", we see the first image, and when the second half of the circuit is "on", the second image shines in the same place that the first had been.


Build a box to house your circuit and transparencies (We used cardboard for our box). Keep in mind the angles you established to get your images shining in the correct spot.


Cut out holes in the box for the motion trigger and power switch. The top of the motion trigger should be poking out of the bottom of the box so that it senses people when they walk under it.


Mount the modules inside the box with tape or Gluedots. Tape the transparencies to the outside of the box. You will want to add a divider down through the center of the box in order to focus the lights on their corresponding images.


Place your box in a strategic place. We hung ours from the ceiling using fishing line.


Get ready to spook your friends! From a distance, a quiet blinking image is seen, but as an unsuspecting victim approaches, the other spooky image suddenly pops up accompanied by an eerie rattling sound. This project has an element of surprise that would be perfect in any haunted house!

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