As I write this, Supercon 2023 is in full swing down in Pasadena — 80 degrees and sunny at the moment, as opposed to 50 and pouring rain where I am, not that I’m bitter. Luckily, though, we can all follow along with the proceedings thanks to the livestreams on the Hackaday channel, which of course will all be available once they’re edited in case you miss anything live. There are a ton of interesting talks coming up, so there’ll be a lot to catch up on when the dust settles. And that won’t be far from now; by the time this post publishes, Supercon will be all but over, which makes it the Thanksgiving dinner of cons — all that work and it’s over in just a few minutes.
With the popularity of Nixie clocks, we’d be forgiven for thinking that the glowing tubes are only good for applications with a stately pace of change. But we forget that before they became the must-have hobbyist accessory, Nixies were used in all kinds of scientific instruments, from frequency counters to precision multimeters. In such applications, update rates in the hundreds or thousands of Hertz aren’t uncommon, and the humble Nixie handled display refreshes with ease.
But what about refreshing a Nixie at 100 kHz? That was the question put to artisanal Nixie maker [Dalibor Farný] by a client who wanted a timer to calibrate high-speed cameras. It was a feat that [Dalibor] wasn’t sure his custom-made tubes could handle. The video below shows his efforts to find out.
If you ever wanted to know about the physics of gas-discharge displays like the Nixie, the fifteen minutes starting at about 5:13 will give you everything you need. That basic problem boils down to the half-life of excited neon, or how long it takes for half the population of excited molecules to return to the ground state. That, in turn, dictates how long a given cathode will continue to visibly glow after it’s turned off, which determines how many digits will appear illuminated at once.
To answer that, they engaged a company in Prague with a camera capable of a mind-blowing 900,000 frames per second. Even though they found a significant afterglow period for each cathode, even at 100 kHz it’s clear which digit is the one that’s currently illuminated. They also looked at the startup of digits in a cold Nixie versus one that’s warmed up, leading to some fascinating footage at around 26:30.
We appreciate [Dalibor]’s attention to detail, not only in the craftsmanship of his custom tubes but in making sure they’re going to do their job. He recently did a failure analysis on some of his high-end clocks that showed the same care for his product and his brand.
We all need an excuse to play Half-Life 2 sometimes. [Jeri Ellsworth] put together a My First Crowbar controller to throw a few headcrabs across the room. It’s pretty much Half-Life 2 for the Wii.
The build is very simple – just a tilt switch hot glued to the underside of a childs-size crowbar. Two leads go from the tilt switch to the contacts on a (PS3?) controller. All you need to do to attack is swing the crowbar wildly.
[Jeri] has us wondering what other awesome game controllers could be made. Of course we’ve been wanting a real-life Gravity Gun or Portal Gun for years now, but right now we’re thinking about a real Katamari. We might need more hot glue.
As far as building our own, we’re thinking about using one of the Cheap DIY tilt switches we saw the other day. It’s a simple build, and sure looks like a lot of fun.
We don’t know how we missed this when it first came out, but there is a hack out there that combines a .22 caliber pistol with the video game Half-life. Simple is best and that motto is in use here. A wall was built down range to use as a projection screen. Accelerometers mounted on the drywall report vibration data from the bullet strike which is used to triangulate its location. This targeting data is then sent to the game interface.
As you can see in the video after the break this works like a charm. The [Waterloo Labs] personnel that developed this are also responsible for that iPhone controlled car. The antics we witnessed in that project carry over to this one as they illustrate using the setup to play Half-life with a couple of shovels at 2:12 into the clip. Continue reading “Live Fire Half-life”