I produce a weekly web-series hosted by the electronics enthusiast Ben Heck. Every week we create new episodes to inspire the engineer and hobbyist community. Usually I stay behind the scenes, but in this episode of The Ben Heck Show, Ben and I work together to create a DIY bike turn signal system.
This is meant as a proof of concept and the basic idea of the turn signals can be modified to look however you like. It doesn't even have to be on a backpack - you could create a system for on the bike and place the switches on the handlebars. Heat up those soldering irons and see what you come up with!