Building Zombie Index Controllers

Valve’s Index Controllers, also known as Knuckles are quite possibly the most interesting input devices when it comes to XR. Since they attach to user’s hands, they don’t need to be held – resulting in the natural, relaxed, open hand being the default gesture.

Their ability to read and translate the movements of individual fingers can be rivaled only by direct hand tracking – but they don’t suffer from the lag that optical hand image processing introduces.

Also – they are the best way to play Half-Life Alyx and I still did not finish it.

I got my Knuckles a long time ago – shipped to me during Valve’s hardware beta. They are virtually the same kit as retail units.

As I picked them up for the first time in a year and realized the batteries were dead. Not dead as in discharged. Dead-dead. The controllers worked and tracked great while plugged, but would not hold the charge. The second I’d unplug them they turned into paperweights.

I am uncertain if it’s a fluke, a problem with a devkit or a wider spread issue, but I did not like the idea of throwing them away. Despite costing nearly $300 for a pair, I simply hated the idea of generating e-waste and throwing away devices due to one component’s failure.

Since developer versions of the controllers were not covered by warranty, RMA was not an option. I found a user-made guide to battery replacement on iFixit, but it seemed a bit too complex for my repair skills.

Since the controllers worked when plugged, I just needed something to plug them into. I found these small portable phone battery banks on Amazon and got one for each controller.

The rest was a matter of some Velcro straps and repurposing the tightening strap already on the controller.

Added weight is not ideal, but I approach it as if exercising with light dumbbells. The battery banks don’t interfere with tracking and stay out of my hands’ range of motion.

Total budget, just over $30, tenth of the cost of new controllers – and no e-waste generated.

Just you wait, Jeff. Alyx is coming for you.