“I always liked the design of the Wii’s Nunchuck controller. But normally you can only use them if they’re physically wired to another device called the Wii Remote. However, with some hardware and software tinkering and time, it’s possible to turn a Nunchuck into a completely stand-alone wireless (PC) joystick. In this post, I’ll briefly go over how I achieved this, as well as share the open-source software and hardware resources I developed along the way.
When opening up a $4 Nunchuck-compatible knockoff, it’s easy to spot its two analog potentiometers, the two digital buttons, a MEMS accelerometer chip, and the tiny microprocessor hidden under a black blob. The microprocessor samples all these inputs, and sends out a digital version of this information over the cable that also supplies the device with power.
In order to convert this joystick into a wireless device, I used a Dremel to remove basically everything that wasn’t essential, leaving only the casing, a copperless PCB, the buttons and the potentiometers. Now, I could have chosen to reuse and repurpose more of the original electronics. But I wanted to optimize for battery life and capacity, and didn’t mind losing the accelerometer functionality and redoing the rest.”