A French Minitel terminal becomes a Raspberry Pi-powered mini laptop.

Minitel Terminal Becomes Mini Laptop

October 8, 2021 by Kristina Panos 17 Comments

In 1980, France took a step into the future when the telecom companies introduced the Minitel system — a precursor to the Web where users could shop, buy train tickets, check stocks, and send and receive electronic mail through a small terminal. Minitel still had 10 million monthly connections in 2009, but the service was discontinued in 2012.

So, you can imagine how many Minitel terminals must be floating around at this point. [Gautchh] picked one up at a garage sale a while back and converted it into a battery-powered laptop for taking notes in class. Luckily for us, [Gautchh] recently open-sourced this project and has given us a wiring diagram, STLs, BOM, and a good look into the build process.

[Gautchh] started by gutting the Minitel, but saved the power button and the très chic power indicator that looks like a AA cell. The new 10.4″ LCD screen is held in place with four 3D-printed corner blocks and a bit of hot glue, and the original keyboard (which we’d love to clack on) is now wired up to an Arduino Pro Micro. The main brain — a Raspberry Pi 3B — is easily accessible through a handy little hatch in the back. Well, it looks like we’ve got a new ebay alert to set up.

In the mood for more AZERTY goodness? Check out this gallery of French computers, or a more traditional take on a Minitel with a Raspberry Pi.

Raspberry Pi Plots World Wide Earthquakes

October 5, 2021 by Dave Rowntree 9 Comments

What do you do when you stumble across a website posting real-time earthquake data? Well, if you’re [Craig Lindley] you write some code to format it nicely onto a display, put it in a box, and watch it whilst making dinner.

[Craig] started off with coding in Forth on the ESP32, using ESP32Forth, but admits it didn’t go so well, ditching the ESP32 for a Raspberry Pi 3 he had lying around, and after a brief detour via C++, he settled on a Python implementation using Pygame.

A case was 3D printed, which he says worked OK, but needs a little tuning to be perfect. There is no shortage of casing options for the Pi with the official 7″ display, [Craig] suggests that it probably wasn’t worth the effort to 3D print the case and if he was building it again would likely use a commercially available option which had a better fit.

When developing the code, and watching it work, he noted clusters of earthquakes around Hawaii, then he found out Kilauea had just gone up. Wow.

For a similar take, check out this other recent build using an ESP32 and the same data source.

CO2 laser cutting ceramic sheet under water film

Water Is The Secret Ingredient When Laser Cutting Ceramics To Make Circuits

October 2, 2021 by Dave Rowntree 21 Comments

[Ben Krasnow] over at Applied Science was experimenting with cutting inexpensive ceramic sheets with his cheap CO2 laser cutter when he found that (just as expected) the thermal shock of the CO2 beam would cause cracking and breaking of the workpiece. After much experimentation, he stumbled upon a simple solution: submersion under a thin layer of water was sufficient to remove excess heat, keeping thermal shock at bay, and eventually cutting the material. Some prior art was uncovered, which we believe is this PHD thesis (PDF) from Manchester University in the UK. This is a great read for anyone wanting to dig into this technique a little deeper.

The CO2 laser cutter is a very versatile tool, capable of cutting and etching a wide range of materials, many of natural origin, such as cardboard, leather and wood, as well as certain plastics and other synthetic materials. But, there are also materials that are generally a no-go, such as metals, ceramics and anything that does not absorb the laser wavelength adequately or is too reflective, so having another string in one’s bow is a good thing. After all, not everyone has access to a fibre laser.

After dispensing with the problem of how to cut ceramic, it got even more interesting. He proceeded to deposit conductive traces sufficiently robust to solder to. A mask was made from vinyl sheet and a squeegee used to deposit a thick layer of silver and glass particles 1 um or less in size. This was then sintered in a small kiln, which was controlled with a Raspberry Pi running PicoReFlow, and after a little bit of scrubbing, the surface resistance was a very usable 2 mΩ/square. Holes cut with the laser, together with some silver material being pushed through with the squeegee formed through holes with no additional effort. That’s pretty neat!

Some solder paste and parts were added to the demo board, and with an added flare for no real reason other than he could, reflowed by simply applying power direct to the board. A heater trace had been applied to the bottom surface, rendering the board capable of self-reflowing. Now that is cool!

Continue reading “Water Is The Secret Ingredient When Laser Cutting Ceramics To Make Circuits” →

Super 8 Camera Brought Back To Life

September 30, 2021 by Bryan Cockfield 32 Comments

The Super 8 camera, while a groundbreaking video recorder in its time, is borderline unusable now. Even if you can get film for it (and afford its often enormous price), it still only records on 8mm film which isn’t exactly the best quality of film around, not to mention that a good percentage of these cameras couldn’t even record audio. They were largely made obsolete by camcorders in the late ’80s and early ’90s, although some are still used for niche artistic purposes. If you’d rather not foot the bill for the film, though, you can still put one of these to work with the help of a Raspberry Pi.

[befinitiv] has a knack for repurposing antique analog equipment like this while preserving its aesthetic. While the bulk of the space inside of this camera would normally be used for housing film, this makes a perfect spot to place a Raspberry Pi Zero, a rechargeable battery, and a power converter circuit all in a 3D printed enclosure that snaps into the camera just as a film roll would have. It uses the Pi camera module but still makes use of the camera’s built in optics which include a zoom function. [befinitiv] also incorporated the original record button so that from the outside this looks like a completely unmodified Super 8 camera.

The camera can connect to a WiFi network and can stream live video to a computer, or it can record video files to an internal SD card. As a bonus, thanks to the power converter circuit, it is also capable of charging a cell phone. [befinitiv] notes that many of the aesthetic properties of 8 mm film seem to be preserved when using this method, and he has several theories as to why but no definitive answer. If you’d like to take a look at some of his other projects like this, check out this analog camera that is now able to take digital pictures. Continue reading “Super 8 Camera Brought Back To Life” →

A conventiongoer plays Pokemon on a working Color Game Boy costume.

Convention Plays Pokemon On Giant Color Game Boy Costume

September 29, 2021 by Kristina Panos 2 Comments

Standard cosplay is fun and all, but what is there for admirers to do but look you up and down and nitpick the details? Interactive cosplay, now that’s where it’s at. [Jaryd Giesen] knows this, and managed to pull together a working color Game Boy costume in a few days.

The original plan was to use a small projector on an arm, like one of those worm lights that helped you see the screen, but [Jaryd] ended up getting a secondhand monitor and strapping it to his chest. Then he took the rest of the build from there. Things are pretty simple underneath all that cardboard: there’s a Raspberry Pi running the RetroPie emulator, a Pico to handle the inputs, and two batteries — one beefy 12,000 mAH battery for the monitor, and a regular power pack for the Pi and the Pico.

As you’ll see in the build and demo video after the break, nearly 100 people stopped to push [Jaryd]’s buttons. They didn’t get very far in the game, but it sure looks like they had fun trying.

Since we’re still in a pandemic, you may want to consider incorporating a mask into your Halloween costume this year. Just a thought.

Continue reading “Convention Plays Pokemon On Giant Color Game Boy Costume” →

Put A Landscape Scanner On Your Bike And Ride

September 27, 2021 by Lewin Day 33 Comments

Google have a fleet of cars travelling the roads of the world taking images for their online StreetView service. You could do much the same thing pedalling on two wheels, with the help of this landscape scanner from [Celian_31].

The basic concept is simple. A powerbank on the bike runs a Raspberry Pi, kitted out with its typical Pi Camera within a 3D-printed housing. A reed switch on the bike’s frame detects pulses from a magnet attached to the valve stem of one tire, and this is used to trigger the taking of photos at regular intervals with the aid of a Python script. Further scripts are then used to knit all the photos taken on a ride together into one contiguous image.

It’s unlikely you’ll recreate Google’s entire StreetView in this fashion. You’d probably want a spherical camera anyway. However, if you wish to undertake regular static surveillance of your local area in an inconspicuous fashion, this would be a great way to do it while also staying in shape. If you do that, please don’t tell us as it would be a major violation of operational security. We’d love to hear about any other projects, though! Video after the break.

Continue reading “Put A Landscape Scanner On Your Bike And Ride” →

A Raspberry Pi-based COVID Green Pass validator verifies a QR code on a phone.

COVID Green Pass Validator With Raspberry Pi

September 25, 2021 by Kristina Panos No comments

It seems like every nation is dealing with the plague a little differently. In June, the EU instated a COVID Green Pass which comes in the form of a paper or digital QR code. It was designed to grease the wheels of travel throughout Europe and allow access to nursing homes. As of early August, the Green Pass is now required of those 12 and older in Italy to gain access to bars and restaurants, museums, theaters, etc. — anywhere people gather in sizeable groups. The Green Pass shows that you’ve either been vaccinated, have had COVID and recovered, or you have tested negative, and there are different half-lives for each condition: nine months for vaccinated, six for recovered, and just forty-eight hours for a negative test.

[Luca Dentella] has built a Green Pass validator using a Raspberry Pi and a Raspi camera. Actual validation must be done through the official app, so this project is merely for educational purposes. Here’s how it works: the user data including their status and the date/time of pass issuance are encoded into a JSON file, then into CBOR, then it is digitally signed for authenticity. After that, the information is zipped up into a base-45 string, which gets represented as a QR code on your phone. Fortunately, [Luca] found the Minister of Health’s GitHub, which does the hard work of re-inflating the JSON object.

[Luca]’s Pi camera reads in the QR and does complete validation using two apps — a camera client written in Python that finds QRs and sends them to the validation server, written in Node.js. The validation server does formal verification including verifying the signature and the business rules (e.g. has it been more than 48 hours since Karen tested negative?) Fail any of these and the red LED lights up; pass them all and you get the green light. Demo video is after the break.

Are you Canadian? Then check this out, eh?

Continue reading “COVID Green Pass Validator With Raspberry Pi” →