A lot of “productivity hackers” have tried the ever-famous Pomodoro Technique. A method of focusing on a task for a given amount of time (25-30 minutes) and taking a break before repeating the cycle. I’ve enjoyed using this technique and decided to make a small dedicated hardware timer as my pomodoro clock. This is significantly more work than using a dollar-store egg timer or a phone timer, but making things is fun, and I’m happy with how my custom 3D printed shell turned out!
The Design…
The design is quite simple. The heart is an ATtiny1604 micro-controller. The button resets the timer to the full 30 minute countdown. As time counts down, the red indicator LEDs disappear until time’s up, at which point the 4 brighter alerting LEDs begin flashing. I chose not to add a buzzer, as I wanted to use this in a workplace environment with people around.
I decided against using a small OLED or numeric display because I initially intended for this project to be very low power, utilizing a CR2032 coin cell. The version pictured however, uses 5V from a USB cable to operate in perpetuity. This was a fun project and the small PCB allows me to re-purpose my extra blanks as little pseudo-development boards for the ATtiny!