One of the common modules used in making Simple Bots is the Blink Module. This involves photocoupling an LED to a bike safety light. When the safety light turns on, the motor turns on and when the light turns off, the motor turns off. On account of this, the motor reacts to the different blink patterns of the safety light and that is, obviously, why it is called a blink module. This module allows you to add a little bit of predictable unpredictability to your bot and is a lot of fun. Add this module to just about any bot for interesting results.

Step 1: Go Get Stuff

You will need:

- A bike safety light
- Simple Light Switch
- 1/2" shrink tubing

Step 2: Remove and Mark

Make a mark on the bike light's clear cover directly atop the center LED.

Remove the cover.

Step 3: Drill

Drill a 3/16" hole in the spot that you marked.

Step 4: Glue

Place the shrink tube over the center LED and insert the photo sensor down into the shrink tube such that the sensor is directly facing the LED.

This is a little unorthodox, but rather than heating the shrink tube with a heat gun and then gluing it, simply hot glue it in place. Aside from holding everything in place, the heat from the hot glue will also compress the shrink tube.

Step 5: Cover

Place the cover back onto the bike light such that the leads from the light sensor are sticking out of the hole you drilled.

The module is now ready to go.