The tree-of-life can represent different meanings, but in this earring, it is a symbol of failure :) Let me explain myself! The wearable consists of 18 RGB LED's and is controlled by an ATtiny1616. A lot of traces were required to control these LEDs individually which are routed in the shape of a tree. The design is inspired by the freeform circuit that I designed two years ago: Freeform tree-of-life on Hackaday

This is the second attempt of the tree-of-life PCB wearable. This first one worked great! The RGB's were able to show any color possible resulting in a beautiful rainbow around the tree. Unfortunately, I made a big mistake with the battery holders. I made the clip ground instead of V+ ....

So, this is the second design! I fixed the battery footprint and now I can power these from little hearing aid batteries. But, the push button was relying on the battery clips to pull to ground, but since the clips are not longer ground, I had to add a wire from the push button to ground (connected to the capacitor).

But that is not all, it gets worse! On this new design the RGB LED's are mounted incorrectly, and as a result only the green LEDs can be controlled individually, while the blue and red LEDs can only be turned on simultaneous. See the video below for the results.

Detailed information

Power is delivered by the two size 13 zinc-air coin cell batteries. These batteries are commonly used in hearing aid, and widely available. On the back of the earring is a push button which can be used to change settings. 13 different modes are available:

• SINGLE CW mode
• SINGLE BOTH DIRECTIONS mode
• SINGLE CCW mode
• SINGLE SPLIT mode
• SINGLE-OUT mode
• DOUBLE CW mode
• DOUBLE SPLIT mode
• DOUBLE CCW mode
• TRIPLE CW mode
• TRIPLE SPLIT mode
• TRIPLE CCW mode
• SEXTUPLE CW mode
• SEXTUPLE SPLIT mode

Specifications

Size: 23mm (7/8"), 43mm from top of hanger

Weight with batteries: 3.8 gram (0.13 oz)

Micro-Controller: ATtiny1616

Batteries: 2x size 13 zinc-air hearing aid batteries

Battery life: ~60 hours