You can what now?

The sensor bar isn't actually a sensor, just two IR blasters that the cameras on the wiimotes use for positioning.

You can use any two sources of infrared light instead!

The sensor bar is ACTUALLY not two IR blasters, but two sets of 5 commodity IR LEDs!

https://forums.dolphin-emu.org/Thread-making-a-diy-wiibar

Before I knew this I had someone pull out their lighter and point the remote at it when our sensor bar died. Took me a little bit to figure it out.

I blame Nintendo for calling their "2 lights bar" that doesn't have any sensor a "sensor bar".

If I were to place you on a team in my company, I'd more likely place you in engineering than marketing :)

It's a bar that the sensors need to find. It's not optimal but it's a fine use.

The sensor bar is passive - it's just two infrared diodes so the Wiimote can get an idea of its own position.

So you can replace it with candles as they emite infrared light as well!

I always thought it was hilariously similar to how to old NES zapper worked - the sensor was in the gun, it decided what you ‘hit’ based on what the sensor saw when the tv flashed. I think it was an early instance of me recognizing an engineering ‘hack’ - instead of the target reporting whether it had been hit, it was the gun reporting whether it thought it had hit the target.

the "sensor" is actually in the remote. The bar is just two infrared leds seperated by a known distance, that the infrared camera in the remote uses to figure out it's position.

I play a bit of flightsim and our head tracking works the same way. Camera receives IR LED position for head movement axis, program does the interpretation of movement.

There's a homebrew head tracking demo [0] for the wii that has you put a sensor bar on your head, and a wiimote on top of your TV. I messed around with it over a decade ago and found it very convincing.

0: https://www.wiibrew.org/wiki/Headtracking

Very convincing indeed. IMO it's almost as good as (if not better than) head mounted VR goggles. At least it doesn't cause motion sickness.

The person who came up with that idea, Johnny Lee¹, went on to work on the xbox and I believe was also involved in development of the Kinect.

1. https://www.youtube.com/@jcl5m

For fun, go look up Johnny Lee Wiimote candles. It showcases it fairly well.

Also man do I feel old - coming up on 15-20 years since that and I actually remember HN discussion about it from the earlier days.

Yeah I was amazed when I first bought a wireless sensor bar, and there was nothing to plug into the console!

Turns out all the smarts are in the controllers, the bar is just there to show a couple of fixed points for positioning.