Thunder Pack Is a Locally-Powered Arm-Based Board for Wearables

18650s freak me out. They can easily be damaged and turned into a fire bomb. This one, attached to you. Beware! But anyway...

Wearable technology is ever-evolving to become smaller, more flexible, and self-contained with its own power supply. The rule of thumb seems to be "the smaller, the better," and senior web developer Jeremy Gillick has managed to design the Thunder Pack — a tiny, Arm-based platform that's battery-powered and fits in your pocket. The idea for the device came about when he got tired of wiring the same components (Arduino, charging controller, and battery) continuously for wearable lighting projects.

Gillick explains, "I wanted something compact, rugged, and could pump out enough current for a lot of blinkenlights without any additional parts. What I've ended up with is this little beast with 4 onboard PWM MOSFETs, each driving up to 2.3A per channel!!! Develop your project faster with onboard LEDs attached to each PWM output — so you can play without wiring anything up."

The Thunder Pack is designed around an STM32F411 running CircuitPython, along with MCP73831 power management IC and an NCR18650B 3400mAh battery. It also packs four onboard PWM MOSFETs (driving up to 2.3A per channel), a USB port, charger, LEDs for status/debugging, a pair of buttons (one on/off, one programmable), and a total of 12 GPIOs.

It's interesting to note Gillick began this project before COVID-19 became a pandemic, and had plans to attend the Open Hardware Summit in NYC, which was subsequently canceled. That said, he did manage to place PCB orders back in mid-February, and although they arrived a month later, it allowed him to finish the Thunder Pack. Those interested in recreating his build can head to his project page, but bear in mind, if you order PCBs and other hardware, it may take weeks or even months to receive them.