Hacker Reverse Engineers and Reuses Hue Light PCBs for Other Projects
Repurpose for your own purposes!
Instead of sending some retired IoT bulbs to electronics recycling, Chris Greening of the YouTube channel atomic14 took another approach. Greening tears down a Hue light, reverse engineers the PCBs, and repurposes them in an educational explanation video.
The video and associated blog post walkthrough Greening's reverse engineering process. The first step is getting the PCBs out of the light bulb enclosure. The most extensive hurdle in this step is the conformal coating on the board. Which, unfortunately, is strong enough that it caused some ICs to come off the PCB while removing that conformal layer!
Greening found three separate PCBs neatly packed inside the bulb: a power board, a control board, and an LED panel. The power board is a straightforward AC-to-DC converter circuit. After spending some quality time with a DMM's continuity mode and KiCad, Greening drew up a schematic of how the LEDs were connected. From there, the focus became the digital/control/RF board.
That board contains a microcontroller, an LDO, and a PCB-based antenna. Interestingly, even though some of the ICs were missing, the board still responded to WiFi commands and lit up (most of) the LEDs! Cleverly, Greening set the colors to a strong R, G, and B to determine which resistors controlled which LED color.
Once Greening knew what color signals controlled which colors, the next step was to replace the LED panel with some LEDs in a breadboard. It is incredible to see the skeletal remains of the Hue light control such simple hardware!
The video above explains each PCB and component. There are also demonstrations of each step of the reverse engineering process. You can also check out the atomic14 blog post for a write-up of this teardown and check out Greening's other equally impressive projects.