LED ring

Jens Hauke designed this charlieplexed 20 LED blinker controlled by an ATTiny45 for the Hackaday Coin Cell Challenge:


LED Ring

This is a small blinky with 20 LEDs powered by one CR2032 coin cell
and with an ATTiny45 brain. The firmware is written in plain C and
compiled with the avr-gcc toolchain. The PCB is a two layer design made
with KiCad.
Space efficient daisychained LED placing with shared anode/cathode soldering pads.

Firmware and gerbers are available on GitHub:



Jens has shared the board on OSH Park:

LED 20 Ring ATTiny


Order from OSH Park

Here is a video of the LED in action:

LED ring

ATtiny45 motion sensing night light

DanR has shared this motion sensing night light board:


ATtiny45 motion sensing night light V1.2 D

This light is powered by an ATtiny45/85 which powers on the 14 LED lights when motion is sensed and it is in a dark room. The light sensor on the board will not allow the lights to come on if it is in a reasonably lit room.

It is fitted with a barrel plug for power, this model specifically with an L7805CV voltage regulator.

Order from OSH Park

ATtiny45 motion sensing night light