Raspberry Pi

1898 Articles

The Decisioninator Decides Dinner, Saves Marriage

September 5, 2025 by 14 Comments

For something non-explosive, this might be the most American project we’ve featured in a while. [Makerinator]’s domestic bliss was apparently threatened by the question “what shall we have for dinner”– that’s probably pretty universal. Deciding that the solution was automation is probably universal to software devs and associated personalities the world over. That the project, aptly called “The Decisioninator” apes a popular game-show mechanic to randomly select a fast-food restaurant? Only people with 100-octanes of freedom running through their veins can truly appreciate its genius.

In form factor, it’s a tiny slot machine which [Makerinator] fabbed up on his laser cutter. The lovely “paintjob” was actually a print out with dye-sublimation ink that was transferred to plywood before laser cutting.  Mounted to this are illuminated arcade buttons and a small ISP display. The interface is simplicity itself: the big button spins a virtual “wheel” on the display (with sound effects inspired by The Price is Right) to tell the family what deliciously unhealthy slop they’ll be consuming, while the other button changes decision modes. Of course you can pick more than just dinner with The Decisioninator. You need only decide what spinners to program. Which, uh, that might be a problem.

Luckily [Makerinator] was able to come up with a few modes without recursively creating a The Decisioninator-inator. He’s got the whole thing running on a Pi4, which, with its 1980s supercomputer performance, is hilariously overpowered for the role it plays (in true American fashion). He’s coded the whole thing in the Flame Engine, which is a game engine built on the Flutter UI toolkit by American technology giant Google.

What’s more American than tech giants and fast food? A propane powered plasma cannon, for one thing; or maybe mental gymnastics to translate into freedom units, for another.

Thanks to [Makerinator] for the tip.

One Camera Mule To Rule Them All

September 3, 2025 by 4 Comments

A mule isn’t just a four-legged hybrid created of a union betwixt Donkey and Horse; in our circles, it’s much more likely to mean a testbed device you hang various bits of hardware off in order to evaluate. [Jenny List]’s 7″ touchscreen camera enclosure is just such a mule.

In this case, the hardware to be evaluated is camera modules– she’s starting out with the official RPi HQ camera, but the modular nature of the construction means it’s easy to swap modules for evaluation. The camera modules live on 3D printed front plates held to the similarly-printed body with self-tapping screws.

Any Pi will do, though depending on the camera module you may need one of the newer versions. [Jenny] has got Pi4 inside, which ought to handle anything. For control and preview, [Jenny] is using an old first-gen 7″ touchscreen from the Raspberry Pi foundation. Those were nice little screens back in the day, and they still serve well now.

There’s no provision for a battery because [Jenny] doesn’t need one– this isn’t a working camera, after all, it’s just a test mule for the sensors. Having it tethered to a wall wart or power bank is no problem in this application. All files are on GitHub under a CC4.0 license– not just STLs, either, proper CAD files that you can actually make your own. (SCAD files in this case, but who doesn’t love OpenSCAD?) That means if you love the look of this thing and want to squeeze in a battery or add a tripod mount, you can! It’s no shock that our own [Jenny List] would follow best-practice for open source hardware, but it’s so few people do that it’s worth calling out when we see it.

Thanks to [Jenny] for the tip, and don’t forget that the tip line is open to everyone, and everyone is equally welcome to toot their own horn.

A hand holding a One ROM with a Commodore 64 in the background

One ROM: The Latest Incarnation Of The Software Defined ROM

September 3, 2025 by 25 Comments

Retrocomputers need ROMs, but they’re just so read only. Enter the latest incarnation of [Piers]’s One ROM to rule them all, now built with a RP2350, because the newest version is 5V capable. This can replace the failing ROMs in your old Commodore gear with this sweet design on a two-layer PCB, using a cheap microcontroller.

[Piers] wanted to use the RP2350 from the beginning but there simply wasn’t space on the board for the 23 level shifters which would have been required. But now that the A4 stepping adds 5 V tolerance [Piers] has been able to reformulate his design.

The C64 in the demo has three different ROMs: the basic ROM, kernel ROM, and character ROM. A single One ROM can emulate all three. The firmware is performance critical, it needs to convert requests on the address pins to results on the data bus just as fast as it can and [Piers] employs a number of tricks to meet these requirements.

The PCB layout for the RP2350 required extensive changes from the larger STM32 in the previous version. Because the RP2350 uses large power and ground pads underneath the IC this area, which was originally used to drop vias to the other side of the board, was no longer available for signal routing. And of course [Piers] is constrained by the size of the board needing to fit in the original form factor used by the C64.

The One ROM code is available over on GitHub, and the accompanying video from [Piers] is an interesting look into the design process and how tradeoffs and compromises and hacks are made in order to meet functional requirements.

Continue reading “One ROM: The Latest Incarnation Of The Software Defined ROM” →

Pi Port Protection PCB

August 25, 2025 by 16 Comments

We’re used to interfaces such as I2C and one-wire as easy ways to hook up sensors and other peripherals to microcontrollers. While they’re fine within the confines of a small project, they do have a few limitations. [Vinnie] ran straight into those limitations while using a Raspberry Pi with agricultural sensors. The interfaces needed to work over long cable runs, and to be protected from ESD due to lightning strikes. The solution? A custom Pi interface board packing differential drivers and protection circuits aplenty.

The I2C connection is isolated using an ISO1541 bus isolator from TI, feeding a PCA9615DP differential I2C bus driver from NXP. 1-wire is handled by a Dallas DS2482S 1-wire bus master and an ESD protection diode network. Even the 5-volt power supply is delivered through an isolated module.

Whether or not you need this Raspberry Pi board, this is still an interesting project for anyone working with these interfaces. If you’re interested, we’ve looked at differential I2C in the past.

The PC In Your Pico

August 18, 2025 by 33 Comments

We’re all used to emulating older computers here, and we’ve seen plenty of projects that take a cheap microcontroller and use it to emulate a classic home computer or gaming platform. They’re fun, but serve mostly as a way to relive old toys.

As microcontrollers become faster though it’s inevitable that the machines they can emulate become more powerful too, so we’re moving into the realm of emulating productivity machines from years past. An example is [Ilya Maslennikov]’s pico-286, which as its name suggests, is a 286 PC emulator for the Raspberry Pi Pico.

It has an impressive set of sound and video card emulations, can drive either a VGA or an HDMI monitor, and uses a PS/2 keyboard and mouse. If DOS games are your thing it should provide what you want, but it’s caught our eye because there was a time when a 286 DOS PC was a productivity machine. There’s a huge library of still-useful software for DOS, and thus the prospect of a handheld DOS PC still has some appeal. We’d love to see someone put this in a badge.

MS-DOS may no longer be for sale, but there are several ways to land an open-source DOS in 2025. FreeDOS is something of a powerhouse.

It’s A Pi, But It’s Not Quite A Raspberry Pi

August 17, 2025 by 17 Comments

When is a Raspberry Pi not a Raspberry Pi? Perhaps when it’s a Pi Pico-shaped board with an RP3A0 SoC from a Raspberry Pi Zero 2, made by [jonny12375].

Back in the early days of the Raspberry Pi, there was a offering from the Korean manufacturer Odroid, which wasn’t merely a similar machine with a different SoC, but a full clone in a smaller form factor featuring the same BCM2385 chip as the original. It was electrically and software-wise identically to the real thing, which we suspect didn’t go down very well with the Pi folks in Cambridge. The supply of Broadcom chips dried up, and ever since then the only way to get a real Pi has been from the official source. That’s not quite the end of the unofficial Pi story though, because a few hardy experimenters have made Pi clones like this one using chips desoldered from the real thing.

It’s the fruit of a reverse-engineering project to find the chip’s pinout, and it’s a proof of concept board rather than the intended final target of the work. The process involved painstakingly sanding down each layer of a Zero 2 board to reveal the traces and vias. The current board has a few quirks but it boots, making this an impressive piece of work on all counts. We’re looking forward to seeing whatever the final project will be.

If you’re hungry for more Pi-derived goodness, we’ve also seen one using the part form a Pi 3.

A black and white device sits on a beige table. A white rotary knob projects out near the base of it's rectangular shape nearest the camera. Near it is a black rectangular section of the enclosure with six white dots protruding through holes to form a braille display. A ribbon cable snakes out of the top of the enclosure and over the furthest edge of the device, presumably connecting to a camera on the other side of the device.

This Polaroid-esque OCR Machine Turns Text To Braille In The Wild

August 15, 2025 by 2 Comments

One of the practical upsides of improved computer vision systems and machine learning has been the ability of computers to translate text from one language or format to another. [Jchen] used this to develop Braille Vision which can turn inaccessible text into braille on the go.

Using a headless Raspberry Pi 4 or 5 running Tesseract OCR, the device has a microswitch shutter to take a picture of a poster or other object. The device processes any text it finds and gives the user an audible cue when it is finished. A rotary knob on the back of the device then moves the braille display pad through each character. When the end of the message is reached, it then cycles back to the beginning.

Development involved breadboarding an Arduino hooked up to some MOSFETs to drive the solenoids for the braille display until the system worked well enough to solder together with wires and perfboard. Everything is housed in a 3D printed shell that appears similar in size to an old Polaroid instant camera.

We’ve seen a vibrating braille output prototype for smartphones, how blind makers are using 3D printing, and are wondering what ever happened with “tixel” displays? If you’re new to braille, try 3D printing your own trainer out of TPU.

Continue reading “This Polaroid-esque OCR Machine Turns Text To Braille In The Wild” →