There was a time in the history of electronics where everyone was obsessed with making things smaller. Products were often released in a “mini” or “micro” variation, and while miniaturization is still a big factor in electronics, it takes a lot to stand out in a world where everything has been reduced to incredibly small sizes.
The ThunderPack 18650, however, proves that makers can still push the envelope. What we have here is an ARM development board that hugs the side of an 18650 Lithium cell. The STM32F11 microcontroller is broken out to a USB port (for programming via the bootloader), with headers for 4 high-power PWM outputs for driving LEDs and 12 GPIOs in a package that fits into your pocket.
There is a power management system that is used to recharge the battery. But you do need to make sure that you choose the style of 18650 that includes built-in protection for low-voltage over-current protection. Jeremy Gillick Labs offers the option of included a battery when purchasing the board.
Jeremy decided to take on this challenge after years of wiring together portable LED controllers that were often fragile and unstable. I would say he’s managed to elevate the concept considerably here.