The strategy with this debounce method is not simply to use a single ISR for the button input, but to activate a second timer-based ISR ... has included some example Arduino code for others ...

Droplet and StackAR, developed by MIT’s Media Lab, allow users to set timers or program an Arduino using light-based communication. By pressing the tool against a screen, flashes of light can ...

[Scott-28] recently sent in a particularly well-documented project that turned an antique rotary phone into a digital kitchen timer using an internal Arduino. While we’re not sure practical is a ...

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.