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.

The creative adventures with ATtiny series microcontroller are awesome if you know how to play them. ATtinys — especially the ATtiny85s — are all around us, and by using one, we can shrink the size of ...