Textmeter Tells Its Tale

One time-proven method to make a lesson memorable is to make it a story, but that is not easy if your core material is the repair log of a rotted out analog ammeter. Most folks don’t need a 300A meter on their drill press, so [Build Comics] converted it to a text display and describes the procedure like they are writing a comic book. He is using HDLO-3416 LED cluster arrays for that dated-but-legible industrial feel, and everything looks right at home in a box made from oak and steel. Even the USB cord even gets a facelift by running it inside a fabric shoelace. In our own lives, covering charging cables is a hack on its own because we don’t want to fumble with the wrong charger when it is time to sleep or drive. Glow-in-the-dark cord upgrades, anyone?

We don’t have a pre-operation picture of the subject, but the innards suggest that it comes from the bottom of an industrial scrap pile. There is a cross-hatch pattern on the front plate, which hinted at 3D printing, but if you look closely at the early images, you can see that it is original. There is a nodeMCU board to fetch the date information and control the four alphanumeric displays. Except for the red lights, all the new hardware hides behind wood or steel, so this old workhorse’s aesthetic lives on and has a story to share that is a delight to read.

If you enjoy reading [Build Comics] and their adventurous recollections, we forecast you’ll enjoy this weather display, or maybe it is time to check out their clock, but we want to plant the seed of literary build logs.

Distorted Text Says A Lot

Getting bounced to a website by scanning a QR code is no longer an exciting feat of technology, but what if you scanned the ingredient list on your granola bar and it went to the company’s page for that specific flavor, sans the matrix code?

Bright minds at the Columbia University in the City of New York have “perturbed” ordinary font characters so the average human eye won’t pick up the changes. Even ordinary OCR won’t miss a beat when it looks at a passage with a hidden message. After all, these “perturbed” glyphs are like a perfectly legible character viewed through a drop of water. When a camera is looking for these secret messages, those minor tweaks speak volumes.

The system is diabolically simple. Each character can be distorted according to an algorithm and a second variable. Changing that second variable is like twisting a distorted lens, or a water drop but the afterimage can be decoded and the variable extracted. This kind of encoding can survive a trip to the printer, unlike a purely digital hidden message.

Hidden messages like these are not limited to passing notes, metadata can be attached to any text and extracted when necessary. Literature could include notes without taking up page space so teachers could include helpful notes and a cell phone could be like an x-ray machine to see what the teacher wants to show. For example, you could define what “crypto” actually means.

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Hide Secret Messages In Plain Sight With Zero-Width Characters

Fingerprinting text is really very nifty; the ability to encode hidden data within a string of characters opens up a large number of opportunities. For example, someone within your team is leaking confidential information but you don’t know who. Simply send each team member some classified text with their name encoded in it. Wait for it to be leaked, then extract the name from the text — the classic canary trap.

Here’s a method that hides data in text using zero-width characters. Unlike various other ways of text fingerprinting, zero width characters are not removed if the formatting is stripped, making them nearly impossible to get rid of without re-typing the text or using a special tool. In fact you’ll have a hard time detecting them at all – even terminals and code editors won’t display them.

To make the process easy to perform, [Vedhavyas] created a command line utility to embed and extract a payload using any text. Each letter in the secret message is converted to binary, then encoded in zero-width characters. A zero-width-non-joiner character is used for 0, and a zero-width-space character for 1.

[Vedhavyas’] tool was inspired by a post by [Tom], who uses a javascript example (with online demo) to explain what’s going on. This lets you test out the claim that you can paste the text without losing the hidden data. Try pasting it into a text editor. We were able to copy it again from there and retrieve the data, but it didn’t survive being saved and cat’d to the command line.

Of course, to get your encoding game really tight, you should be looking at getting yourself an enigma wristwatch

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Landscape Lighting That Also Texts

Your local hardware store or garden supply center probably has everything you need to install landscape lighting all around your property. What’s a little less likely is coming out of that situation with fewer holes in your wallet than in your yard. And even then, it’s pretty much guaranteed that any off-the-shelf equipment won’t send you a text message when your landscape lighting isn’t working properly. [Mark]’s landscape lighting system does, though!

Powered by a Raspberry Pi, this landscape lighting system has every feature imaginable. It can turn the lighting on at sunset and turn it off at a set or random time later in the evening. There’s a web interface served from the Pi that allows further user control. The Raspberry Pi also monitors the lighting and can sense when one of the lights burns out. When one does, the Pi uses Twillo to send a text message notification.

There’s not many more features we can imagine packing into a setup like this. Of course, if you don’t have a spare Pi around you can probably manage to get the job done with an ESP8266, or even an old-fashioned Arduino.

The Stork Looks Different Than We Thought

What the Internet of Things really needs is more things, and the more ridiculous the better. At least, that’s the opinion of [Eric] who has created a tongue-in-cheek gadget to add to the growing list of connected devices. It’s a Bluetooth-enabled pregnancy test that automatically releases the results to the world. Feeling lucky?

The theory of operation is fairly straightforward. A Bluetooth low-energy module is integrated into the end of a digital pregnancy test. These tests have a set of photo detectors to read the chemical strip after the test is conducted. If the test is positive, the module sends a signal to a Raspberry Pi which tweets the results out for the world to see. It also has an option to send a text message to your mom right away!

[Eric]’s project to live-tweet a pregnancy test also resulted in a detailed teardown of a digital pregnancy test, so if you need any technical specifications for pregnancy tests (for whatever reason) his project site has a wealth of information. He does note that his device can be used on other similar devices with directly driven LCD screens, too. The fun doesn’t end there, though! Once the pregnancy is a little further along you’ll be able to get the baby on Twitter, too.

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Chatbox Wireless IM Client

[Utpal Solanki] wanted to do some text chatting from the comfort of the couch. He built this wireless chat client that he calls Chatbox using a microcontroller, a character LCD screen, and a keypad that he built himself.

The device communicates via an Infrared emitter and receiver. It pairs up with an Arduino using an IR shield that [Utpal] built. The handheld unit flashes a pair of white LEDs whenever it receives a message from the Arduino. You can then hit the Inbox button and scroll through to read what was received. To reply  just type on the keypad the same way you would with a cellphone, then hit the send button to shoot that message back to the Arduino.

On the computer side of things the messages are being relayed to and from the Arduino over a USB connection. Early on in the video demonstration (embedded after the break) [Utpal] shows his Chat Box program communicating via the handheld unit in the same way that other messenger programs work.

Looks to us like he’s built his own non-pink version of what the IM-ME was originally intended to do.

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