This is a simple Pomodoro style timer I made using a Proto Shield, an Arduino clone, a NeoPixel 24 LED ring clone, and various bits and pieces from my parts drawer.
The single button is wired to pin 3 of the Arduino using a simple RC debounce circuit featured some time ago on Hackaday. It's probably not needed, but what the hell.
The LED ring is wired to pin 6 (like it is in every NeoPixel code example I've seen so far). As suggested a few places, I have a 470 ohm resistor in series with the data pin, and a electrolytic capacitor across VCC and GND. Like the debounce circuit, these are also probably not needed.
- Long button presses (> 500ms) will turn the device on and off. This also resets the timer.
- Short button presses will add 1 minute to the current timer.
- Each pomodoro consists of 25 minutes of work (red color) followed by a short 5 minute pause (yellow color).
- Every fourth pause is a longer one of 25 minutes (green color).
- Between each pomodoro, the device will briefly flash which number is (blue color). 1 quarter of the ring = 1 pomodoro.