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

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.

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Suggested Schematic Standards

We often think that if a piece of software had the level of documentation you usually see for hardware, you wouldn’t think much of it. Sure, there are exceptions. Some hardware is beautifully documented, and poorly documented software is everywhere. [Graham Sutherland’s] been reviewing schematics and put together some notes on what makes a clean schematic.

Like coding standards, some of these are a bit subjective, but we thought it was all good advice. Of course, we’ve also violated some of them when we are in a hurry to get to a simulation.

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2025 One Hertz Challenge: Educational Tool Becomes 10 Stopwatches

Around the globe, some classrooms are using fancy digital handheld devices to let people answer questions. One such example of this hardware is the Smart Response PE. These devices are largely useless outside the classroom, so [Ray Burne] decided to hack one for our 2025 One Hertz Challenge.

The Smart Response PE device is similar in shape and size to an old-school candybar cellphone. It runs on a Texas Instruments CC2533 microcontroller, which drives a simple black-and-white LCD. User interface is via a numeric keypad and a few extra control buttons on the front panel. Thanks to Github user [serisman], there are readily available development tools for this hardware. [Ray] notes it provides a straightforward Arduino-like programming experience.

[Ray] decided to modify the hardware to act as a stopwatch. But not just one stopwatch—ten stopwatches at once! Pressing a number from 0 to 9 will activate that given timer, and it will start ticking up on the LCD screen. One can pause the screen updates to get a temporary laptime reading by pressing the enter key. Meanwhile, pressing the Home button will reset the screen and all timers at once. [Ray] also explains on the project page how to add a real power switch to the device, and how to modify the programming pins for easy access.

It’s a fun build, and one that could prove useful if you regularly find yourself having to time ten of something at once. Maybe eggs? In any case, it’s certainly easier than juggling ten separate stopwatches at once! Meanwhile, if you’re hacking your own obscure hardware finds, don’t hesitate to notify the tipsline!

A before and after with the plank of wood shown and the resulting chair also shown.

Liberating A Collapsible Chair From A Single Piece Of Wood

Over on his YouTube channel our hacker [GrandpaAmu] liberates a collapsible chair from a single piece of wood.

With the assistance of an extra pair of hands, but without any power tools in sight, this old master marks up a piece of wood and then cuts a collapsible chair out of it. He uses various types of saw, chisels, a manual drill, and various other hand tools. His workspace is a humble plank with a large clamp attached. At the end he does use a powered hot air gun to heat the finish he uses to coat the final product.

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2025 One Hertz Challenge: An Arduino-Based Heart Rate Sensor

How fast does your heart beat? It’s a tough question to answer, because our heart rate changes all the time depending on what we’re doing and how our body is behaving. However, [Ludwin] noted that resting heart rates often settle somewhere near 60 bpm on average. Thus, they entered a heart rate sensor to our 2025 One Hertz Challenge!

The build is based around a Wemos D1 mini, a ESP8266 development board. It’s hooked up to a MAX30102 heart beat sensor, which uses pulse oximetry to determine heart rate with a photosensor and LEDs. Basically, it’s possible to determine the oxygenation of blood by measuring its absorbance of red and infrared wavelengths, usually done by passing light through a finger. Meanwhile, by measuring the change in absorption of light in the finger as blood flows with the beat of the heat, it’s also possible to measure a person’s pulse rate.

The Wemos D1 takes the reading from the MAX30102, and displays it on a small OLED display. It reports heart rate in both beats per minute and in Hertz. if you can happen to get your heartrate to exactly 60 beats per minute, it will be beating at precisely 1 Hertz. Perhaps, then, it’s the person using Ludwin’s build that is actually eligible for the One Hertz Challenge, since they’re the one doing something once per second?

In any case, it shows just how easy it is to pick up biometric data these days. You only need a capable microcontroller and some off-the-shelf sensors, and you’re up and running.

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Gentle Processing Makes Better Rubber That Cracks Less

Rubber! It starts out as a goopy material harvested from special trees, and is then processed into a resilient, flexible material used for innumerable important purposes. In the vast majority of applications, rubber is prized for its elasticity, which eventually goes away with repeated stress cycles, exposure to heat, and time. When a rubber part starts to show cracks, it’s generally time to replace it.

Researchers at Harvard have now found a way to potentially increase rubber’s ability to withstand cracking. The paper, published in Nature Sustainability, outlines how the material can be treated to provide far greater durability and toughness.

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Hackaday Podcast Episode 333: Nightmare Whiffletrees, 18650 Safety, And A Telephone Twofer

This week, Hackaday’s Elliot Williams and Kristina Panos met up over the tubes to bring you the latest news, mystery sound, and of course, a big bunch of hacks from the previous week.

In Hackaday news, get your Supercon 2025 tickets while they’re hot! Also, the One Hertz Challenge ticks on, but time is running out. You have until Tuesday, August 19th to show us what you’ve got, so head over to Hackaday.IO and get started now. Finally, its the end of eternal September as AOL discontinues dial-up service after all these years.

On What’s That Sound, Kristina got sort of close, but this is neither horseshoes nor hand grenades. Can you get it? If so, you could win a limited edition Hackaday Podcast t-shirt!

After that, it’s on to the hacks and such, beginning with a talking robot that uses typewriter tech to move its mouth. We take a look at hacking printed circuit boards to create casing and instrument panels for a PDP-1 replica. Then we explore a fluid simulation business card, witness a caliper shootout, and marvel at one file in six formats. Finally, it’s a telephone twofer as we discuss the non-hack-ability of the average smart phone, and learn about what was arguably the first podcast.

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!

Download in DRM-free MP3 and savor at your leisure.

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