When you're cycling or riding a motorcycle, proper signaling to the people around you is essential to making sure that they -- and you -- get home safely. We've shown you a number of bike signal projects before, but this DIY brake light backpack is a little easier to build.
The video above from the fine folks at Adafruit Industries walks you through the process from start to finish; hit the link below for the the full guide if you're interested in making one for yourself. You'll need a Flora accelerometer, a battery pack, a wireless module to control the lights, and the LEDS to make this project work (all of the parts are available at the project page).
The accelerometer automatically senses when you're braking and will activate your brake lights as you're slowing down. Te wireless module lets you toggle the left or right signals whenever you're getting ready to turn. The LEDs are bright and easily seen at night.
Flora Brake Light Backpack [Adafruit]