Based on a discussion at Hackaday Europe 2024 the idea was born to build a 7-minute timer for the Sunday lightning talks. Based on this, a brainstorming resulted in the following list of features:
- 7-minutes countdown timer
- Blinky
- Visible for speaker and audience
- Easy to read
- Alarm (1 minute left)
Initial idea was to use a 7-segment display on four sides, but later a custom 5x7 matrix was designed to be more flexible with the animations and functions. The timer was designed in Fusion 360.

Full function is shown in this video (12x faster):
The timer is powered by a USB powerbank, mounted to the inner structure. There is a service opening at the top to access the controller, reset button and USB cable for charging.

The timer was successfully used for the Sunday lightning talks at Hackaday Europe 2025.