Raspberry Pi

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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” →

A Robot Controller With The Compute Module 5

August 6, 2025 by 16 Comments

The regular Raspberry Pi line is a flexible single-board computer, but sometimes you might find yourself wishing for a form factor that was better designed for installation into a greater whole. This is why the Compute Module variants exist. Indeed, leveraging that intention, [Hans Jørgen Grimstad] has used the powerful Compute Module 5 as the heart of his “Overlord” robot controller.

The Compute Module 5 offers a powerful quad-core 64-bit ARM chip running at 2.4 GHz, along with anywhere from 2 to 16GB of RAM. You can also get it with WiFi and Bluetooth built in onboard, and it comes with a wide range of I2C, SPI, UART, and GPIO pins to serve whatever ends you envision for them. It’s a whole lot of capability, but the magic is in what you do with it.

For [Hans], he saw this as a powerful basis for a robot controller. To that end, he built a PCB to accept the Compute Module 5, and outfit it with peripherals suited to robotics use. His carrier board equips it with an MCP2515 CAN controller and a TJA1051 CAN transceiver, ideal for communicating in a timely manner with sensors or motor controllers. It also has a 9-axis BNO055 IMU on board, capable of sensor fusion and 100Hz updates for fine sensing and control. The board is intended to be easy to use with hardware like Xiaomi Cybergear motors and Dynamixels servos. As a bonus, there is power circuitry on board to enable it to run off anything from 5 to 36V. While GPIOs aren’t exposed, [Hans] notes that you can even pair it with a second Pi if you want to use GPIOs or camera ports or do any other processing offboard.

If you’re looking for a place to start for serious robot development, the Overlord board has plenty of capability. We’ve explored the value of the Compute Module 5 before, too. Meanwhile, if you’re cooking up your own carrier boards, don’t hesitate to let the tipsline know!

A photo of the HAT with the LoRa module and relay visible on the top

LoRaSense Pi Hat Aims To Kick Start IoT Projects

August 5, 2025 by 9 Comments

[Avi Gupta] recently sent in their LoRaSense RGB Pi HAT project. This “HAT” (Hardware Attached to Top) is for any Raspberry Pi with 40-pin header. The core of the build is the custom printed circuit board which houses the components and interconnects. The components include an SHT31 temperature and humidity sensor, an SX1278 LoRa module, and a 10 amp 220 VAC relay. The interconnects include support for UART, I2C, SPI, and WS2812B RGB LED interfaces as well as a stackable header for daisy chaining HATs.

The attached components in combination support a wide range of use cases. Possible uses for this Raspberry Pi HAT include smart home systems, agricultural projects, industrial monitoring, smart greenhouse, remote weather stations, or alerting systems. You can detect weather conditions, send and receive information, switch mains powered loads, and use RGB LEDs for status and alerting.

If you’re interested in LoRa technology be sure to read about the Yagi antenna that sends LoRa signals farther.

Closeup of WOPR interface on Raspberry Pi

Rebooting WarGames‘ WOPR With A Pi And Gemini

July 30, 2025 by 4 Comments

WarGames fans, rejoice: [Nick Bild] has rebooted WOPR for real. In his latest hack, the Falcon, he recreates the iconic AI from the 1983 film using a Raspberry Pi 400, a vintage SP0256-AL2 speech chip from General Instrument, and Google’s Gemini LLM. A build to bring us back to the Reagan-era.

Where most stop at visual homage, this one simulates true interaction. The Python script acts as dungeon master for Gemini 2.5 Flash, guiding it to roleplay as the WOPR computer. Keypress sounds click-clack in synchrony with every input. Gemini replies are filtered into allophones, through GI-Pi, [Nick]’s own Python library. The SP0256 then gives it an eerily authentic robotic voice, straight out of 1983.

[Nick] himself is no unfamiliar name to Hackaday. Back in 2020, he hosted a Hack Chat where he talked us through getting from ideas to prototype builds. He practices what he preaches, since he carried out projects like a breadboard 6502 computer, home-automation controlling AI sunglasses, and more silly inventions, like dazzle-proof glasses.

So… shall we play a game? If you’ve ever longed to chat with an 80s military AI about thermonuclear war or tic-tac-toe without doubting you end the world in a blink, start on this build.

Continue reading “Rebooting WarGames‘ WOPR With A Pi And Gemini” →

Quasi-Quantifying Qubits For 100 Quid

July 14, 2025 by 3 Comments

As part of his multi-year project to build a quantum computer, hacakday.io poster [skywo1f] has shared with us his most recent accomplishment — a Nuclear Magnetic Resonance Spectrometer, which he built for less than $100.

The NMR spectrometer is designed to disturb protons, which naturally line up according to the Earth’s magnetic field, using an electric coil. Once disturbed, the protons nutate (a fancy physics word for wobble), and flip quantum spin states. [skywo1f]’s NMR device can detect these spin state changes, as he demonstrates with a series of control experiments designed to eliminate sources of false positives (which can be annoyingly prevalent in experimental physics). His newest experimental device includes a number of improvements over previous iterations, including proper shielding, quieter power topology, and better coil winding in the core of the device. Everything was assembled with cost in mind, while remaining sensitive enough to conduct experiments — the whole thing is even driven by a Raspberry Pi Pico.

Here at Hackaday, we love to see experiments that should be happening in million-dollar laboratories chugging along on kitchen tables, like this magnetohydrodynamic drive system or some good old-fashioned PCB etching. [skywo1f] doesn’t seem to be running any quantum calculations yet, but the NMR device is an important building block in one flavor of quantum computer, so we’re excited to see where he takes his work next.

Convert Any Book To A DIY Audiobook?

July 6, 2025 by 12 Comments

If the idea of reading a physical book sounds like hard work, [Nick Bild’s] latest project, the PageParrot, might be for you. While AI gets a lot of flak these days, one thing modern multimodal models do exceptionally well is image interpretation, and PageParrot demonstrates just how accessible that’s become.

[Nick] demonstrates quite clearly how little code is needed to get from those cryptic black and white glyphs to sounds the average human can understand, specifically a paltry 80 lines of Python. Admittedly, many of those lines are pulling in libraries, and some are just blank, so functionally speaking, it’s even shorter than that. Of course, the whole application is mostly glue code, stitching together other people’s hard work, but it’s still instructive and fun to play with.

The hardware required is a Raspberry Pi Zero 2 W, a camera (in this case, a USB webcam), and something to hold it above the book. Any Pi with the ability to connect to a camera should also work, however, with just a little configuration.

On the software side, [Nick] pulls in the CV2 library (which is the interface to OpenCV) to handle the camera interfacing, programming it to full HD resolution. Google’s GenAI is used to interface the Gemini 2.5 Flash LLM via an API endpoint. This takes a captured image and a trivial prompt, and returns the whole page of text, quick as a flash.

Finally, the script hands that text over to Piper, which turns that into a speech file in WAV format. This can then be played to an audio device with a call out to the console aplay tool. It’s all very simple at this level of abstraction.

Continue reading “Convert Any Book To A DIY Audiobook?” →

The door-unlocking mechanism, featuring a 3D printed bevel gear and NEMA 17 stepper.

Hack Swaps Keys For Gang Signs, Everyone Gets In

July 2, 2025 by 12 Comments

How many times do you have to forget your keys before you start hacking on the problem? For [Binh], the answer was 5 in the last month, and his hack was to make a gesture-based door unlocker. Which leads to the amusing image of [Binh] in a hallway throwing gang signs until he is let in.

The system itself is fairly simple in its execution: the existing deadbolt is actuated by a NEMA 17 stepper turning a 3D printed bevel gear. It runs 50 steps to lock or unlock, apparently, then the motor turns off, so it’s power-efficient and won’t burn down [Binh]’s room.

The software is equally simple; mediapipe is an ML library that can already do finger detection and be accessed via Python. Apparently gesture recognition is fairly unreliable, so [Binh] just has it counting the number of fingers flashed right now. In this case, it’s running on a Rasberry Pi 5 with a webcam for image input. The Pi connects via USB serial to an ESP32 that is connected to the stepper driver. [Binh] had another project ready to be taken apart that had the ESP32/stepper combo ready to go so this was the quickest option. As was mounting everything with double-sided tape, but that also plays into a design constraint: it’s not [Binh]’s door.

[Binh] is staying in a Hacker Hotel, and as you might imagine, there’s been more penetration testing on this than you might get elsewhere. It turns out it’s relatively straightforward to brute force (as you might expect, given it is only counting fingers), so [Binh] is planning on implementing some kind of 2FA. Perhaps a secret knock? Of course he could use his phone, but what’s the fun in that?

Whatever the second factor is, hopefully it’s something that cannot be forgotten in the room. If this project tickles your fancy, it’s open source on GitHub, and you can check it out in action and the build process in the video embedded below.

After offering thanks to [Binh] for the tip, the remaining words of this article will be spent requesting that you, the brilliant and learned hackaday audience, provide us with additional tips.

Continue reading “Hack Swaps Keys For Gang Signs, Everyone Gets In” →