Circuit card: $2.00
BOM Digikey $5.60
WS2812B: $3.25 (Normally a quarter a piece on e-bay)
Ornament_WS2812 – Drawings and BOM
This ornament was a fun little project. This LED’s are normally driven with 60mA of current each. Since I am supplying the power with a couple of coin batteries we had to play a few tricks. First of all, only two of the LED’s are lit at any one time. I tried to use only one, but there was too much flicker. Second, all the LED’s are driven at 1/16 of the normal current, which is a little under 4mA.
The ornament is turned on by pressing the push button, and then at the end of the sequence it automatically turns itself off. The programming is done on a PIC processor in assembly language. To make the sequencing easier, there is a color pallet of just eight colors. The video above shows the sequencing for the lights.