Read QR Codes Without A Computer

January 22, 2024 by Al Williams 21 Comments

Did you ever watch Star Wars and wondered how people understood what R2D2 was saying? Maybe [Luke Skywalker] would enjoy learning to decode QR Codes by hand, too. While it might not be very practical, it would be a good party trick — assuming, like us, you party with nerds.

You can start by scanning a code, or the site will create one according to your specifications or generate one randomly. It then takes the selected code and shows you how it is put together. Fun fact: 21×21 “modules” (QR-speak for pixels) is the size of a version 1 QR code. Each version increases the size by four modules.

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Building A 60s Toy The Way It Should Have Been

February 2, 2021 by Dan Maloney 24 Comments

The original Hasbro “Think-a-Tron”, a toy from the dawn of the computer revolution, was billed with the slogan, “It thinks! It answers! It remembers!” It, of course, did only one of these things, but that didn’t stop the marketers of the day from crushing the hopes and dreams of budding computer scientists and their eager parents just to make a few bucks. It’s not like we’re bitter or anything — just saying.

In an effort to right past wrongs, [Michael Gardi] rebuilt the 1960s “thinking machine” toy with modern components. The original may not have lived up to the hype, but at least did a decent job of evoking the room-filling computers of the day is a plastic cabinet with a dot-matrix-like display. The toy uses “punch-cards” with printed trivia questions that are inserted into the machine to be answered. A disk with punched holes spins between a light bulb and the display lenses, while a clever linkage mechanism reads the position of a notch in the edge of the card and stops the wheel to display the letter of the correct answer.

[Michael]’s update to the Think-aTron incorporates what would have qualified as extraterrestrial technology had it appeared in the 1960s. A 35-LED matrix with a 3D-printed diffuser and case form the display, with trivia questions and their answer as a QR code standing in for the punch-cards.He also added a pair of user consoles, so players can lock-in and answer before an ESP32-Cam reads the QR code and displays the answer on the LED matrix, after playing some suitable “thinking music” through a speaker.

As usual with [Michael]’s retrocomputing recreations, the level of detail here is fantastic. We especially like the custom buttons; controls like these seem to be one of his specialties judging by his slide switches and his motorized rotary switch.

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A QR Code, Step By Step

November 5, 2018 by Jenny List 22 Comments

We should all be familiar with QR codes, those blocky printed patterns containing encoded text, URLs, or other data. A few years ago they were subject to their own cloud of hype, but now they have settled down in their niche of providing a handy route for a smartphone owner to reach a website without having to type an address.

Have you ever wondered how they work? There are plenty of dry technical guides out there, but if they’re not your thing you might find [Nayuki]’s step-by-step guide to be of interest. It explains the encoding and error checking bit generation process before starting on the familiar three-squares pattern and timing bars of the QR code itself. The really interesting part comes with its explanation of overlays, a set of repeating patterns that are added to the final data segment, and how the pattern used is chosen to minimise penalties due to large blocks of the same colour in the final piece. The chances are most of us will never have to create a QR code from scratch, but it is this type of fascinating technical general knowledge that makes guides like this such an interesting read.

QR codes have appeared in quite a few projects here over the years, but the one we find particularly amusing is this project to hack them by changing one QR into another.

Via Hacker News.

E Pluribus Unix, QR-Style

June 28, 2016 by Elliot Williams 9 Comments

It’s been a long time since we’ve logged into a UNIX mainframe (other than our laptop) but one of our fond memories is the daily fortune: small, quirky, sometimes cryptic sayings that would pop up on the login screen if your system administrator had any sense of humor.

Apparently, we’re not alone. [Alastair] made his own fortune clock which gives you a new “fortune” every second instead of every login. There’s a catch, of course. It’s a QR clock — the fortune is encoded in a QR code instead of being displayed in human-readable form. You have to take a picture of the tiny OLED screen to know what it says. (Watch it sending him Shakespeare sonnets in the video below.)

You probably know QR codes are good for conveying URLs, but their use as general-purpose text containers is underappreciated in our book, so we’re glad to see this example. Now, we’ve seen QR clocks before (here, and here), and this version does have the disadvantage that you can actually tell what time it is. But we’re grateful for the trip down memory lane.

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QR Clock Is Unreadable By Humans And Computers Alike

October 29, 2012 by Brian Benchoff 44 Comments

The clock is a perfect technology. For just a few dollars, you can buy a digital wristwatch and chronometer able to keep extremely accurate time for years without winding a spring or replacing a battery. Anything ‘improvement’ on the design of a clock only makes it harder to read, a feature exploited by the very 1337 binary clocks we see from time to time. [Ch00f] decided it was time to give way to the march of progress and build a completely unreadable clock. He came up with a QR code clock that is unreadable by humans and cellphones alike.

The hardware is built around nine 8×8 LED matrix panels resulting in a 24 x 24 pixel display, perfect for displaying a 21 pixel square QR code. The LED drivers are a standard multiplexed affair, but this project really shines in the firmware department.

The microcontroller [Ch00f] used – an ATMega328 – is far too small to store the 1440 QR codes for every minute of the day. No, this project would have to dynamically generate QR codes on the fly, not exactly an easy problem.

After looking over the official QR code standard, [Ch00f] wrote a rather large program that turns alphanumeric sequences into QR code. This runs on the microcontroller every minute, generating a new QR code for every minute of the day.

It’s nigh impossible for a human to read a QR code, but [Ch00f] figured he could make his project even less useful. By multiplexing the LEDs at a very low duty cycle [Ch00f] made it impossible for a camera to capture the entire QR code, even though the pattern of pixels is still visible to the human eye. A fabulously useless build that really steps up the game for unreadable clocks.

Video after the break.

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Hackit: Consumer RFID

March 2, 2009 by Nick Caiello 29 Comments

Touchatag

RFID seems to have invaded every part of our lives. Sure, the technology has been primarily used in government and industry, but that doesn’t mean that it doesn’t have consumer applications. Recently, we posted about [max’s] RFID dorm room lock, that he built to provide a safe, convenient way to access his room. A while back, we talked about an RFID spatially aware address book that used a combination of rfid tags and post-it notes to control the NFC enabled Nokia 3220 cell phone. Both of these projects highlight unique applications where RFID is used. We bash on RFID from time to time, mostly due to its security (or lack there of). That said, there is an interesting consumer solution out there for people who want to voluntarily use RFID called Touchatag (formerly known as Tikitag). The cool thing about Touchatag is that it uses a combination of RFID and QR (2-D barcode) tags to trigger applications on the Touchatag website. The starter kit, which includes 10 tags and a USB RFID reader, goes for about $40; a decent price considering the hacking potential for the RFID reader. In addition to using the reader, you can also use any NFC enabled phone to read the tags. While NFC enabled phones are currently few and far between, the technology will likely be implemented in many of the new phones released in the coming year.

We’re curious, what do you think is next for consumer RFID? What kind of innovative project ideas do you have?