DIY Geiger Counter Is Sure To Generate Clicks

August 19, 2019 by Kristina Panos 19 Comments

On the outside, a Geiger counter seems like a complicated thing. And you might think a device that detects a dangerous, mostly invisible threat like radiation should be complicated. But they’re actually pretty simple. The Geiger-Muller tube does most of the work, which boils down to detecting brief moments of conductivity caused by chain reactions of charged particles in radioactive materials.

[Prabhat_] wanted to build a unique-looking Geiger counter, and we’d say that this slick, Star Trek-esque result succeeds. A well-organized display shows the effective dose rate, counts per minute, and cumulative dose, which can be displayed in either microsieverts or millirems. We dig the 3D printed case design, because we like to see form follow function.

The counter is powered by an 18650 cell that’s DC-to-DC boosted to 400+ volts. A NodeMCU processes the signal coming in from the G-M tube and expresses it in both clicks and LED blinks, both of which can be toggled on or off from the home screen. The alert threshold can be customized in the settings, which means the point at which green changes to red.

Click-click-click past the break for [prabhat_]’s great walk-through video, where he tests it with uranium ore and a thoriated gas lantern mantle.

If you want to take the opposite approach and get to clicking ASAP, well, fire up your hot glue gun and dump out your scrap bin.

Continue reading “DIY Geiger Counter Is Sure To Generate Clicks” →

Electric Vehicles On Ice

August 16, 2019 by Sharon Lin 10 Comments

This winter, a group of electric vehicle enthusiasts, including [Dane Kouttron], raced their homemade electric go-karts on the semi-frozen tundra nearby as part of their annual winter tradition. These vehicles are appropriately named Atomic Thing and Doom Sled, and need perfect weather conditions to really put them to the test. You want a glass-like race track but snowfall on ice freezes into an ice-mush intermediate that ends up being too viscous for high-speed ice vehicles. The trick is to watch for temperatures that remain well below zero without snow-like precipitation.

The group is from the community makerspace out of MIT known as MITERS and already have EV hacking experience. They retrofitted their VW Things vehicle (originally built for a high speed electric vehicle competition) to squeeze even more speed out of the design. Starting out with an 8-speed Shimano gearbox and a 7kW motor, they assembled a massive 24S 10P battery out of cylindrical A123 cells salvaged from a Prius A123 Hymotion program. This monster operates at 84V with a 22AH capacity, plenty for power for the team to fully utilize the motor’s potential.

The battery is ratchet strapped to the back of the Atomic Thing to provide more traction on the ice. It must feel just like riding on top of a different kind of rocket.

Original configuration of battery packs

Battery packs ratchet strapped

They tried using ice skates in the front of the Atomic Thing, but the steering was difficult to control over rough ice. Studded solid tires perform quite well, resulting in less jarring movement for the driver. Doom Sled is a contraption built from a frame of welded steel tube and a mountainboard truck with ice skate blades for steering. The motor — a Motenegy DC brush [ME909] — was salvaged from a lab cleanout, transferring power to the wheels through a chain and keyed shaft. The shaft-to-wheel torque was duly translated over two keyed hub adapters.

The crew fitted a seat from a longscooter and made a chain guard from aluminum u-channel to keep the flying chain away from the driver’s fingers. The final user interface includes a right-hand throttle and a left-hand “electric brake” (using resistors to remove the stored energy quickly to combat the enormous inertia produced by the vehicle).

Overall, ice racing was a success! You can see the racing conditions were just about perfect, with minimal ice mush on the lake. Any rough patches were definitely buffered smooth by the end of the day.

Continue reading “Electric Vehicles On Ice” →

Turning A Sony Into A Leica Through Extreme Camera Modding

August 16, 2019 by Jenny List 12 Comments

The quality of a photograph is a subjective measure depending upon a multitude of factors of which the calibre of the camera is only one. Yet a high quality camera remains an object of desire for many photographers as it says something about you and not just about the photos you take. [Neutral Gray] didn’t have a Leica handheld camera, but did have a Sony. What’s a hacker to do, save up to buy the more expensive brand? Instead he chose to remodel the Sony into a very passable imitation.

This is a Chinese language page but well worth reading. We can’t get a Google Translate link to work, but in Chrome browser, right clicking and selecting “translate” works. If you have a workaround for mobile and other browsers please leave a comment below.

The Sony A7R is hardly a cheap camera in the first place, well into the four-figure range, so it’s a brave person who embarks on its conversion to match the Leica’s flat-top aesthetic. The Sony was first completely dismantled and it was found that the electronic viewfinder could be removed without compromising the camera. In a bold move, its alloy housing was ground away, and replaced with a polished plate bearing a fake Leica branding.

Extensive remodelling of the hand grip with a custom carbon fibre part followed, with significantly intricate work to achieve an exceptionally high quality result. Careful choice of paint finish results in a camera that a non-expert would have difficulty knowing was anything but a genuine Leica, given that it is fitted with a retro-styled lens system.

We’re not so sure we’d like to brace Leica’s lawyers on this side of the world, but we can’t help admiring this camera. If you’re after a digital Leica though, you can of course have a go at the real thing.

Thanks [fvollmer] for the tip.

ESP8266 Controls TiVo Over The Network

August 11, 2019 by Tom Nardi 13 Comments

Remember the TiVo? The set-top DVR that was once so popular of a hacking target that Hackaday had a dedicated subdomain for it has today largely faded into obscurity as time-shifted viewing has given way to Internet streaming services like Netflix and Hulu. But make no mistake, while the TiVo may no longer be the centerpiece of the average home entertainment center, there’s a diehard group of antennaed aficionados that are still rocking (and hacking) them.

One such TiVotee is [Thomas McQueen], who recently discovered his TiVo-powered Virgin Media V6 DVR was listening for commands on the network. After finding some official documentation for the protocol and firing off a couple of test commands from his computer’s telnet client, he realized he had an opportunity to flex his microcontroller muscle and create a library that would allow controlling the set-top box with the ESP8266 or other network-capable MCU.

[Thomas] built his project on-top of the basic Arduino WiFi library, making every effort to make it as generalized as possible so it could work on a multitude of platforms and with various targets. He even made sure to give all his functions friendly names that won’t leave users scratching their head when they read through example code down the road. We’ve seen far too many software projects that were poorly documented or obtusely programmed, so it’s always good to see somebody putting some forethought into their code.

The library makes it easy to add TiVo control to your project, but [Thomas] went one step further and came up with an example application that provides a web interface on the ESP8266 or ESP32. Any device with a web browser, such as a smartphone, can connect to the UI and fire off commands to the TiVo. His next step is to combine his library with some code to talk to Amazon’s Alexa so he’ll be able to control playback with his voice.

We’ll hand it to these TiVo users, they’re a tenacious lot. Earlier in the year, we covered how one dedicated TiVo fan managed to brute-force the child lock on his DVR using the Arduino and an IR LED.

The GENIAC Lives Again

August 8, 2019 by Tom Nardi 31 Comments

[Mike Gardi] credits his professional successes in the world of software development on the fact that he had access to logic-based educational games of a sort that simply don’t exist anymore. Back in the 1960s, kids who were interested in electronics or the burgeoning world of computers couldn’t just pick up a microcontroller or Raspberry Pi. They had to build their “computers” themselves from a kit.

One of those kits was the GENIus Almost-automatic Computer (GENIAC), a product which today is rare enough to essentially be unobtainable. Using images and documentation he was able to collect online, [Mike] not only managed to create a functioning replica of the GENIAC, but he even took the liberty of fixing some of the issues with the original 60-odd year old design.

Fundamentally, the GENIAC is composed of rotary switches which feed into each other to perform rudimentary logical functions. With banks of incandescent bulbs serving as the output, users could watch how placing the switches in different positions would influence the result.

This might seem a little silly to modern audiences, but thanks to a well written manual that featured a collection of compelling projects, the GENIAC managed to get a lot of mileage out of a couple light bulbs and some wire. In fact, [Mike] says that the GENIAC is often considered one of the first examples of an interactive electronic narrative, as the carefully crafted stories from the manual allowed players to go on virtual adventures long before the average kid had ever heard of a “video game”. A video about how one of these stories, “The Uranium Shipment and the Space Pirates“, can be seen after the break. Even today it would be an interesting enough toy, but back in 1955 it would have been mind-blowing.

Construction of this replica will require access to a laser cutter so you can approximate the original’s drilled Masonite backing and rotors. From there, [Mike] has produced an array of 3D printable components which are attached to the board to serve as contacts, spacers, and various other pieces of bric-a-brac. Some of the parts he couldn’t find pictures of, so he was forced to come up with his own designs. But considering the finicky nature of the original, he thinks his printed parts may actually be better than what the toy shipped with.

If you like his work with GENIAC, be sure to check out the 3D printed replica of “The Amazing Dr. Nim” that [Mike] made last year, or his breathtaking recreation of the Minivac 601.

Continue reading “The GENIAC Lives Again” →

Arduino Traffic Light Sings The Song Of Its People

August 7, 2019 by Tom Nardi 29 Comments

Getting an old traffic light and wiring it up to do its thing inside your house isn’t exactly a new trick; it’s so common that it wouldn’t normally pass muster for these hallowed pages. Even using one up to show the real-time status of your build or system resource utilization would be pushing it at this point. To get our attention, your traffic light is going to need to have a unique hook.

So how did [Ronald Diaz] manage to get his project to stand out from the rest? Interestingly enough, it’s nothing you can see. His traffic light doesn’t just look the part, it also sounds like the real thing. With far more effort and attention to detail than you’d probably expect, he’s made it so his Australian pedestrian traffic light correctly mimics the complex chirping of the original.

Working from a video of the traffic light on YouTube, [Ronald] was able to extract and isolate the tones he was after. Performing spectral analysis on the audio sample, he was able to figure out the frequency and durations of the eleven individual tones which make up the complete pattern. From the 973 Hz tone that only lasts 25 ms to the continuous 500 Hz “woodpecker”, every element of the sound was meticulously recreated in his Arduino code.

The Arduino Pro Mini used to control the traffic light is not only responsible for playing the tones through a piezo speaker, but as you might expect, for firing off the relays which ultimately control the red and green lamps. With everything carefully orchestrated, [Ronald] can now get that authentic Australian side-of-the-road experience without having to leave the comfort of his own home.

If you’d rather your in-home traffic light be more useful than realistic, we’ve got plenty of prior art for you to check out. This traffic light that tells you how the value of Bitcoin is trending is a great example. Or maybe this one that can tell you if the Internet is down.

Continue reading “Arduino Traffic Light Sings The Song Of Its People” →

Sniffed Transformer Puts Wired Doorbell Online

August 6, 2019 by Tom Nardi 30 Comments

There’s certainly no shortage of “smart” gadgets out there that will provide you with a notification, or even a live audiovisual stream, whenever somebody is at your door. But as we’ve seen countless times before, not everyone is thrilled with the terms that most of these products operate under. Getting a notification on your phone when the pizza guy shows up shouldn’t require an email address, credit card number, or DNA sample.

For [Nick Touran], half the work was already done. There was already a traditional wired doorbell in his home, he just had to come up with a minimally invasive way to link it with Home Assistant. He reasoned that he could tap into the low-voltage side of the doorbell transformer and watch for the telltale fluctuations that would indicate the bell was doing its thing. The ESP8266 has an ADC to measure voltage and WiFi to connect to Home Assistant, so it seemed like the perfect bridge between old and new.

Of course, as with any worthwhile project, it ended up being a bit more complicated. Wired doorbells generally operate on 16-24 VAC, and [Nick] knew if he tried to put his Wemos D1 across the line he’d release the critical Magic Smoke. What he needed was a voltage divider circuit that would take low-voltage AC and drop it to an even lower DC voltage that the microcontroller could cope with.

The simple circuit [Nick] comes up with cuts the voltage way down and removes the negative component completely. So what was originally 18.75 VAC turned into a series of 60 Hz blips at 2.4 VDC; perfect for feeding into a microcontroller ADC. With a baseline to work from, he could then write some code that would watch for variations in this signal to determine when the bell was ringing.

Or at least, that was the idea. While the setup worked well enough on the bench, its performance in the real-world left something to be desired. If his house guest had a heavy hand, it worked great. But a quick tap of the doorbell button would tend to go undetected. After investigating the issue, [Nick] found that he needed to use some software trickery to ensure the ESP8266 was able to keep up with the speedy signal. Once he was able to reliably detect short and long button presses, the rest was just a simple matter of sending an MQTT message to his automation system.

Compared to the hoops we’ve seen other hackers have to jump through to smarten up their doorbells, we think [Nick] got off fairly easy. This project is also an excellent example of how learning about circuit design and passive components can still come in handy in the Arduino Era.

Continue reading “Sniffed Transformer Puts Wired Doorbell Online” →