Runner and Arduino enthusiast Nikodem Bartnik has created a DIY 100m sprint timer which is placed at the finish line and signals the start of timing via an audible bleep from its integrated speaker.

This hack was built for [Hlesliebole]’s Nikon D3100, but he says it should work with any DSLR and remote shutter. This initial build uses an LED as a stand-in for the remote shutter that he ordered.

The Arduino microcontroller takes over from there and executes your code on the Arduino. During upload, if your Arduino has an RX (Receive) LED built-in, you should see it flash rapidly as it ...

Like pretty much all of us, [Andy Schwarz] loves RGB LEDs. Specifically he likes to put them on RC vehicles, such as navigation lights on airplanes or flashers and headlights on cars. He found hims… ...