In the past few weeks, you've already learned how to make your bike light up at night with some DIY rim lights and handlebar lights. But how about something a little more functional? Instead of using those tedious hand signals (which drivers don't even understand), spruce up your ride with some do-it-yourself LED turn signals.
With a little electrical work, you can wire yourself up a sweet pair of LED turn signals that mount directly to the frame, just like Instructables user Adambowker98.
To build it, you'll need a power enclosure, 9V battery, battery snap, two 10 ohm resistors, and of course, some LEDs and an LED holder.
All in all, it involves nothing you couldn't get from a local electronics shop (or online), and the entire project is a fairly straightforward build. To make one of these turn signal boxes, hit up the full tutorial.
If you have more than one bicycle, it's probably better to make a more portable turn signal device, like this DIY turn signal jacket from Leah Buechley. You'll need some Arduino know-how and some sewing skills for this one.
The turn signals sewn into the jacket's back are activated by the buttons in the sleeves, and you'll be using conductive thread to connect the LEDs, LilyPad, power supply, and switches. It's even machine washable!
It's quite a bit more complicated than the box mount, but imagine how awesome you'll look cruising down the street. To make your own signal coat, check out the full tutorial.