Pomodoro technique is a useful time management technique. There have been written a lot about pomodoro technique ever since it was published by Francesco Cirillo in the late 1980-s.
The technique recommends using a mechanical timer for measuring time. There are several reasons for using a mechanical timer: ticking timer reminds about pomodoro in progress and presumably boosts focus.
Conventional kitchen timers are very nice, but they are not particularly convenient for office environment. They are ticking, and their ringing is too loud and very difficult to adjust. There are many apps for pomodoro technique timer, but I’ve always wanted something that satisfies my requirements and has a physical button rather than a virtual one. I tried retrofitting existing timers and toys. It turned out to be easier to build an electronic timer. It also looks very techy.
You can find the eagle project files here. I used oshpark community order for PCBs. You can order this PCB here The firmware is available here I used sparkfun USBtiny ISP to program it.
The timer has five binary positions for displaying remaining minutes. It also has LEDs for busy and available mode. You can tell your colleagues that if the light is red then you are busy. The timer goes off with an audible beep. The whole system is designed the way that you can use arduino IDE to compile the firmware and program the device.
A general view of the timer.