Back in the day, like gun games are a big deal. Duck Hunt, VirtuaCart, Pound to the Dead to name just a few. Unless you have an old school TV though, you just can't play these anymore. Until now at least, as far as I know nobody has tried tackling this before, but I've made a simple device that makes almost any like gun game playable again on modern TVs. But first, before we get onto that, it'd be useful to take a look at how like gun games work and why they don't work anymore. The key thing to understand about CRTs is that the video signal coming into the TV pretty much drove the beam that actually drew the picture directly. If the console was outputting the brightness of a particular pixel, then the TV would be displaying that pixel at that moment. Light gun games use this to detect what pixel they are pointing at. The light gun has a lens which acts a bit like a telescope, focusing the light of the pixel it's pointed at onto a sensor inside the gun. When you press the trigger, on most light gun games, the screen flashes white. When the TV starts displaying the white pixel, the gun is pointed at. The sensor detects the bright light and sends a signal back to the console. As the console knows what pixel it was currently outputting at the time, it now knows the pixel the light gun is pointed at. On new TVs, this is completely broken. The whole frame is normally read in, processed which adds even more delay, and then displayed almost at once. Therefore, when the light sensor detects the light and sends it back to the console, it's really much too late and the console has already assumed the shot was off screen. This is where my device comes in. The video signal coming out of the console gets split between the TV and my device. My device waits for a particular pixel, checks if it's bright and flashes the LED if it is. The LED gets inserted into the barrel of the gun, mimicking the flash light on a CRT TV. This removes all the delay introduced by TV because it's no longer involved. However, this doesn't solve the actual problem of knowing what pixel you are pointed at. Luckily for us though, Nintendo themselves already solved this for us. The Wii remotes, when combined with the centre bar, are very good at determining where they are pointing. With a small bit of calibration, we can get a one-to-one mapping between where the Wii mode is pointing and the parts of the screen we are aiming at. We just need to strap it to the side of the light gun. A Raspberry Pi reads the Wii mode data and sends it to an Arduino so it knows what pixel to inspect and when to flash the LED. With all that in place, here we are playing Duck Hunt, on a real nays with a Reels appa. Albeit a Reels appa with an LED held in the end of the barrel by Blutek and a Wii mode held onto the side with elastic bands. As my device is sitting between the console and the TV, we can also inject new data into the video signal. If we want, we can add a reticle to the display and play it Wii style. And because the way nays light gun games work, we can even change the difficulty. This is because consoles like the Nays and the Sega Math system weren't fast enough to make light gun games work as I showed earlier. They used a similar system that requires less precise timing. When you press the trigger, they first draw a completely black frame. This is an anti-cheap measure. Then each target is drawn as a white square. If the console receives a signal from the light gun within that frame, then it counts as a hit. So for nays and maths system games, we can alter the difficulty by changing the radius at which we check for light. But this is not just a solution for playing 8 bit games. More up-to-date systems are also supported. If sticking the LED onto the end of a Virtua gun, we get to enjoy some classic Virtua Cop on the Sega Saturn, one of my favourite all-time light gun games. Or if Virtua Cop isn't your bag, how about sticking it into a Dreamcast gun and playing some house to the dead too? So there it is, a Raspberry Pi to interface with a Wii mode. As we know, to sample at the right point in a frame, and a small bit of analog circuit tree to read the video signal, is all it's up to resurrect several generations of retro light gun games. If you want to know more, I'll post everything up on GitHub, like normal. I hope you enjoyed the video.