Using Nuclear Decay As Random Number Generator Source For An MCU

November 13, 2023 by Maya Posch 1 Comment

Although there are many ways to get a random number generator (RNG) set up on a microcontroller, it’s hard to argue with the sheer randomness of the various kinds of radiation zipping all around us from nuclear decay events. For [gbonacini] the purchase of a Geiger counter first in 2022 was the reason to tinker with using these as the source for an RNG, which simply runs a counter until a Geiger counter event occurs that ‘selects’ a number and the counter is reset to zero.

With the next version of this system the hardware and layout has changed somewhat, using a commercial handheld Geiger counter (GMC-320+) and its audio output as a generic input for any MCU. The (pulsed) audio signal is amplified with an opamp (left unspecified) that connects to a GPIO pin of the MCU (RP2040-based Pico W). Here the same algorithm is used to create a continuous queue of randomly picked numbers, which can also be queried via the WiFi interface with a custom protocol, essentially making it a network-connected RNG that could be used by other network-connected appliances.

C++ source is provided for the Pico W example, but it should be easy enough to adapt to other platforms. The GMC-320+ is also among the more affordable Geiger counters out there, even if it’s somewhat bulky to pair with just a single MCU, making a more basic Geiger counter module better for a permanent installation. Either way you should get pretty good RNG this way without splurging on exotic hardware.

Thanks to [navigator] for the tip.

Hackaday Links: May 7, 2023

May 7, 2023 by Dan Maloney 39 Comments

More fallout for SpaceX this week after their Starship launch attempt, but of the legal kind rather than concrete and rebar. A handful of environmental groups filed the suit, alleging that the launch generated “intense heat, noise, and light that adversely affects surrounding habitat areas and communities, which included designated critical habitat for federally protected species as well as National Wildlife Refuge and State Park lands,” in addition to “scatter[ing] debris and ash over a large area.”

Specifics of this energetic launch aside, we always wondered about the choice of Boca Chica for a launch facility. Yes, it has all the obvious advantages, like a large body of water directly to the east and being at a relatively low latitude. But the whole area is a wildlife sanctuary, and from what we understand there are still people living pretty close to the launch facility. Then again, you could pretty much say the same thing about the Cape Canaveral and Cape Kennedy complex, which probably couldn’t be built today. Amazing how a Space Race will grease the wheels of progress.

Continue reading “Hackaday Links: May 7, 2023” →

Nuke Your Own Uranium Glass Castings In The Microwave

April 26, 2023 by Dan Maloney 20 Comments

Fair warning: if you’re going to try to mold uranium glass in a microwave kiln, you might want to not later use the oven for preparing food. Just a thought.

Granted, uranium glass isn’t as dangerous as it might sound. Especially considering its creepy green glow, which almost seems to be somehow self-powered. The uranium glass used by [gigabecquerel] for this project is only about 1% U₃O₈, and isn’t really that radioactive. But radioactive or not, melting glass inside a microwave can be problematic, and appropriate precautions should be taken. This would include making the raw material for the project, called frit, which was accomplished by smacking a few bits of uranium glass with a hammer. We’d recommend a respirator and some good ventilation for this step.

The powdered uranium glass then goes into a graphite-coated plaster mold, which was made from a silicone mold, which in turn came from a 3D print. The charged mold then goes into a microwave kiln, which is essentially an insulating chamber that contains a silicon carbide crucible inside a standard microwave oven. Although it seems like [gigabecquerel] used a commercially available kiln, we recently saw a DIY metal-melting microwave forge that would probably do the trick.

The actual casting process is pretty simple — it’s really just ten minutes in the microwave on high until the frit gets hot enough to liquefy and flow into the mold. The results were pretty good; the glass medallion picked up the detail in the mold, but also the crack that developed in the plaster. [gigabecquerel] thinks that a mold milled from solid graphite would work better, but he doesn’t have the facilities for that. If anyone tries this out, we’d love to hear about it.

Congratulations Low-Power Winners

April 13, 2023 by Elliot Williams 13 Comments

Congratulations to the winners of the 2023 Hackaday.io Low Power Contest! We challenged you to show us how much you could do with how little, and you did not disappoint. Our judges have put their heads together, and thanks to Digi-Key, our contest sponsor, the top three entries will be taking home a $150 gift certificate for yet more hacking supplies.

We saw a great diversity of ideas here, all on the low-power theme. So without further ado…

The Prize Winners

[Christoph]’s Ultra Low Power RF-Sensor arose out of necessity. Having just repaired a shower drain, he couldn’t be sure that it wouldn’t start leaking again at some point in the future, but couldn’t go ripping up the floor under the shower tray every week to check. He needed a remote moisture sensor that would do the job for a long time with no intervention.

This superb solution combines an Atmel ATmega328P, an HDC1080 humidity sensor, a 433 MHz radio transmitter, and an RTC to keep power consumption super-low when everything else is shut down. Idling at 600 nA total most of the time, taking a reading every 15 minutes, this device should last for 12 years, and it’s been installed and running for five so far, so we’d say that it’s already proven itself very worthy of taking home the prize here.

[BleakyTex]’s Compact, low-power Geiger counter is absolutely the lowest power Geiger counter we’ve ever seen and maybe also the cutest. With the ambitious goal of running up to two years on two tiny LR44 batteries and a proven runtime of about six months by now, this is the radiation detector you can take with you every day, should you need to. The key is a custom HV section that’s designed for efficiency and the screen – even today, it’s still hard to beat the low power consumption of the humble LCD screen. All this, and it still makes those satisfying clicks when it’s enabled. [BleakyTex] says he might make a kit from this, and we absolutely hope he does!

[mircemk]’s Microwatt Pulse Motor took one of our suggestions in the announcement of the contest and ran with it. This eight-pole handmade electric motor doesn’t actually do anything other than spin, but it does that when hooked up to a literal potato. Pulling around 40 mA at 600 mV, it can easily run on solar power with enough power left over to charge up a battery for when the sun doesn’t shine. All of this is made with extremely simple circuitry and parts scavenged from old relays with a sewing needle held up by a magnet for the bearing. This is pure ingenuity and a sweet low-power demo.

Continue reading “Congratulations Low-Power Winners” →

Hackaday Podcast 192: Supercon Was Awesome, How To Grind ICs And Make Your Own Telescope

November 11, 2022 by Tom Nardi 1 Comment

This week, Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi are still flying high on their post-Supercon buzz (and are a bit jet lagged) this week. We’ll start with some of the highlights from our long-awaited Pasadena meetup, and talk a bit about the winner of this year’s Hackaday Prize. Talk will then shift over to shaved down NES chips, radioactive Dungeons and Dragons gameplay, an impressive 3D printed telescope being developed by the community, and the end of the Slingbox. Stick around for a double dose of Dan Maloney, as we go over his twin treatises on dosimetry and the search for extraterrestrial life.

Download it, burn it on a floppy, and you’ll have it forever!

Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Continue reading “Hackaday Podcast 192: Supercon Was Awesome, How To Grind ICs And Make Your Own Telescope” →

Detecting Radiation For Fun And Profit

November 9, 2022 by Al Williams 19 Comments

It used to be that every well-stocked doomsday bunker had a Geiger counter. These days, you don’t have to have a big tube-based meter. You can inexpensively get a compact digital instrument to handle your radiation detection needs. [DiodeGoneWild] reviews and tears down such a unit from FNIRSI. The case looks like several other similar instruments we’ve seen lately, so presumably, someone is mass-producing these handheld meter cases. You can see the video, below. The meter reads the absolute radioactivity and can also measure cumulative exposure.

After measuring a few common radioactive items, we get to the teardown. Inside, of course, is an ordinary tube. A few screws reveal a typical rechargeable battery, a fairly simple PCB with a microcontroller and battery backup for the real-time clock. A lot of the board is involved in multiplying voltage up to the several hundred volts required for the Geiger tube.

The other side of the PCB has only buttons, a vibration motor, and, of course, the LCD. We don’t know how you might test the relative accuracy other than comparing it to a known-good meter. The bare tube was, of course, more sensitive without the plastic cover, but that could be calibrated out, too.

A Geiger counter doesn’t have to have a lot of parts. Either way, a surprising number of things will set them off.

Continue reading “Detecting Radiation For Fun And Profit” →

Roll The Radioactive Dice For Truly Random D&D Play

November 2, 2022 by Dan Maloney 22 Comments

When you have a bunch of people gathered around a table for a “Dungeons & Dragons” session, you have to expect that things are not always going to go smoothly. After all, people who willingly create and immerse themselves in an alternate reality where one bad roll of the dice can lead to the virtual death of a character they’ve spent months or years with can be traumatic. And with that trauma comes the search for the guilty — it’s the dice! It’s always the dice!

Eliminating that excuse, or at least making it statistically implausible, is the idea behind this radioactively random dice roller. It comes to us from [Science Shack] and uses radioactive decay to generate truly random numbers, as opposed to the pseudorandom number generators baked into most microcontrollers. The design is based on [AlphaPhoenix]’s muon-powered RNG, but with a significant twist: rather than depending on background radiation, [Science Shack] brought the power of uranium to the party.

They obtained a sample of autunite, a weird-looking phosphate mineral that contains a decent amount of uranium, perfect for stimulating the Geiger counter built into the dice roller. Autunite also has the advantage of looking very cool under UV light, taking on a ghostly “fuel rod glow,” in the [Homer Simpson] sense. The decay-powered RNG at the heart of this build is used to simulate throws of every standard D&D die, from a D4 to a D100. The laser-cut hardboard case holds all the controls and displays, and also has some strategically placed openings to gaze upon its glowing guts.

We really like the design, but we have to quibble with the handling of the uranium ore; true, the specific activity of autunite is probably pretty low, but it seems like at least some gloves would have been in order.

Continue reading “Roll The Radioactive Dice For Truly Random D&D Play” →