You might think that a nuclear explosion is not something you need a detector for, but clearly not everyone agrees. [Bigcrimping] has not only built one, the BhangmeterV2, but he has its output publicly posted at hasanukegoneoff.com, in case you can’t go through your day without checking if someone has nuked Wiltshire.
The Bhangmeter is based on an off-the-shelf “nuclear event detector”, the HSN-1000L by Power Device Corporation.
Interfacing to the HSN-1000L is very easy: you give it power, and it gives you a pin that stays HIGH unless it detects the characteristic gamma ray pulse of a nuclear event. The gamma ray pulse occurs at the beginning of a “nuclear event” precedes the EMP by some microseconds, and the blast wave by perhaps many seconds, so the HSN-1000 series seems be aimed at triggering an automatic shutdown that might help preserve electronics in the event of a nuclear exchange.
[Bigcrimping] has wired the HSN-1000L to a Raspberry Pi Pico 2 W to create the BhangmeterV2. In the event of a nuclear explosion, it will log the time the nuclear event detector’s pin goes low, and the JSON log is pushed to the cloud, hopefully to a remote server that won’t be vaporized or bricked-by-EMP along with the BhangmeterV2. Since it is only detecting the gamma ray pulse, the BhangmeterV2 is only sensitive to nuclear events within line-of-sight, which is really not where you want to be relative to a nuclear event. Perhaps V3 will include other detection methods– maybe even a 3D-printed neutrino detector?
If you survive the blast this project is designed to detect, you might need a radiation detector to deal with the fallout. For identifying exactly what radionuclide contamination is present, you might want a gamma-ray spectrometer.
It’s a sad comment on the modern world that this hack feels both cold-war vintage and relevant again today. Thanks to [Tom] for the tip; if you have any projects you want to share, we’d love to hear from you whether they’d help us survive nuclear war or not.
Mock testing is good, but when you’re testing for Disaster Recovery purposes it really is worth while running the best test you can do.
Now, where do you get a small nuke…
The Best Korea – where Supreme Leader compensates for his erectile inadequacy with massive transporter erector launchers flaunting equally massive phallic-shaped rockets. They are supposed to be fitted with small nukes.
Actually filled with people who beat him at Tic-Tac-Toe.
You make it yourself, with plutonium the Libyan terrorists brought you. It’s not just for DeLoreans, ya know!
Or you could ask Jurek Owsiak about enriched uranium. Gun-type bomb is pretty simple and reliable (just ask Hiroshima residents!) When doing bulk purchase he could probably offer you the stuff at discount prices.
Seriously, here’s a bit of vitrified uranium with Jurek’s autograph: https://www.youtube.com/watch?v=5dFX_HWqmTM
Apparently, it sold for $18k.
Jeff has a few of them.
That’s really cool, but how can we find out that it actually works…. Can anyone point us to a source for home-sized thermonuclear devices that we could use to test the sensor?
I thought I had one once, but it turned out that the crazy-haired guy I sourced it from had given me a case full of used pinball machine parts instead. Tried to remonstrate with him in the Twin Pines shopping mall parking lot a few nights later, and, well…
You mean the Lone Pine Mall?
You win the internet, today.
The first rule of personal collections of thermonuclear devices is: ‘Don’t talk about personal collections of thermonuclear devices.’
If there are endless alternate realities, then we all have a personal collection of thermonuclear devices. Somewhere in some reality. :)
“You, at the back of the classroom! Is that a thermonuclear device you’re hiding under your desk? Well, mister, I hope you brought enough for everyone…” 😂
THERMOnuclear?
No.
This is not a hydrogen bomb.
Inner voice…’don’t ask about cobalt bombs…don’t ask…’
Snarky inner voice…’I do have enough for EVERYONE.’
press that test button monthly…
That’s exactly what it’s used for. Keeps the aircraft flying so the crew can drop the bomb before they die.
The idea that there was enough demand for a “nuclear event detector” that someone actually tooled up to make commercial chips…… is not a comforting thought.
Welcome to the 1950s, 60s, 70s, and 80s. Also, the 2020s, because we don’t learn.
It’s a common feature of radiation resistant military equipment. The situations where it would be used are very not comfortable.
Ok, so my only question is where did they get a radiation hardened raspberry pi Pico 2 W. Or is it protected with graded-Z shielding. Or is it inside a large lead, I was going to say box or chest but it would probably need to be a, building to attenuate the intensity enough to keep on working. The SoC is made with a 28 nm process, for some reason I suspect that a 6502 with fewer transistors and made with a 8000 nm process may survive more intense radiation for longer.
They should reach out to Ben Eater and maybe “The Society for Radiological Protection”
They should indeed have used a pico 1 and not a 2.
The relative speeds of the gamma which the HSN-1000L detects and the speed of the blast wave differ sufficiently over a couple of miles that it should have enough time to detect and upload before the blast hits.
Silicon on insulator technologies are best suited for radiation. I think the RCA1802 had a version built that way.
This is an interesting gizmo.. Seems like if it detects something that would be of zero use to biologicals. If it is set off, you are done. But as they mentioned, it might detect something just barely soon enough to shunt some power and protect something from EMP. I’d love to learn more about how that works. I can build a Faraday cage and I know that nuke-hardened electronics are made, but I would love to learn specifics.
However I am still on team nothing ever happens; this is all for academic interest only
Curious what exactly this signal is called….
Doomsday*?
Not_dead_yet?
Maybe just “nBang!”
The datasheet for the Maxwell Technologies HSN-1000 says that pin 2 is NED (active low Nuclear Event Detection signal).
Detection threshold is 10^5 rads/s. So, a LD50 dose in an eyeblink, a prompt kill in less than a second.
If this triggers and you’re anywhere nearby, you’re probably already dead. You just might not know it yet. The only thing that might save you is if the exposure time is less than a millisecond.
If wikipedia is accurate, the highest energy pulse in nuclear detonation lasts less than a microsecond.
The most useless device ever. If I had one and it went off, I’m already dead, and so is everyone else I care about.
I’ve had enough of system support to last at least one lifetime. I’m certainly not interested in a post-mortem support task to keep anything else running for you lot.
I use it to send a command to power up my Aleph in case I’m caught in a nuclear blast.
So, uh, what happened to the BhangmeterV1?
A better question I think is what will be in V3
I’d use this as a dead man’s switch, once triggered, it would send all the angry emails in my drafts folder, or upload the Epstein files to the internet.
Don’t forget to delete the browser history :-)
Connect it up to a conveyor to automatically bring in the tomato plants?
Pointless on the nuclear war angle, but I wonder if it’s sensitive enough to be useful in creating a hobbyist network to detect these:
May 21, 2025
When lightning strikes: Gamma-ray burst unleashed by lightning collision
https://phys.org/news/2025-05-lightning-gamma-ray-unleashed-collision.html
I simply leave an unlit candle by the windowsill. If the candle lights by itself, then a nuke probably went off nearby. It’s also useful for detecting housefires.