PixMob units are wearable LED devices intended for crowds of attendees at events like concerts. These devices allow synchronized LED effects throughout the crowd. [yeokm1] did a teardown of one obtained from a preview for the 2019 Singapore National Day Parade (NDP), and in the process learned about the devices and their infrastructure.

PixMob hardware has been known to change over time. This version has two RGB LEDs (an earlier version had only one), an unmarked EEPROM, an unmarked microcontroller (suspected to be the Abov MC81F4104), and an IR receiver module. Two CR1632 coin cells in series power the device. [yeokm1] has made the schematic and other source files available on the teardown’s GitHub repository for anyone interested in a closer look.
One interesting thing that [yeokm1] discovered during the event was the apparent source of the infrared emitter controlling the devices. Knowing what to look for and reasoning that such an emitter would be mounted with a good view of the crowd, [yeokm1] suspected that the IR transmitter was mounted on a lighting tower. Viewing the tower through a smartphone’s camera revealed a purplish glow not visible to the naked eye, which is exactly the way one would expect an IR emitter to look.
Sadly, there wasn’t any opportunity to record or otherwise analyze the IR signals for later analysis but it’s possible that the IR protocol might be made public at some point. After all, running custom code on an earlier PixMob board was made possible in part by asking the right people for help.





The build is one that should be achievable by anyone with basic dressmaking skills. White and lavender tutus are combined to form the base of the skirt, with a lace outer layer sewn on to create an attractive silhouette for the lights. A USB battery pack is hidden in a pocket in the back to power the show. A WS2812B LED strip is then attached to the skirt, and hidden behind an additional layer of white faux-fur to help diffuse the light.


The wings are a leathercraft project, consisting of a harness worn around the torso. This serves as the mounting point for the fiber optics, as well as the RGB Critter flashlight used to drive the lightshow. Leather parts are lasercut to the right shape, making it easy to create the delicate feather shapes in the design. The pieces are then dyed appropriately and sewn together into the final shape. Bundles of optical fibers are then wound through the harness, sprouting from either shoulder of the wearer. EVA foam is used to help create the right shape for the wings, allowing the different layers to remain separated to create more visual depth.