What is it?

NumiClock Mini is a single numitron display style clock with lipo battery backup as well as a small supercap backup.

The main Micro is an ATMEGA328 running at 1mhz, fw uses interrupts and timers to allow for low power sleep mode to conserve battery power.

Two pin uart interface for debugging custom fw.

Firmware and board is open source and fully hackable.

Why did you make it?

Hackaday square inch contest, plus I wanted a small numitron style clock.

What makes it special?

It's tiny! The board is one square inch. The tube just stands above the board itself. Support for 3v lipo battery backup with on board usb charging. Mini supercap backup if the lipo should fail or loose power.

Voltage or'ing system switches over before power is lost to save rtc contents.

User interface via two small buttons. Built in menu system to set time, set alarm, display temp with time, don't display temp, show time only when user button is pressed. And more features to come.

old demo video