Game Boy vs. Electronic Shelf Labels

SANYO DIGITAL CAMERAWhile they’re probably rare as hen’s teeth in the US, there have been a few major stores around the world that have started rolling out electronic shelf labels for every item in the store. These labels ensure every item on a shelf has the same price as what’s in the store’s computer, and they’re all controlled by an infrared transceiver hanging on the store’s ceiling. After studying one of these base stations, [furrtek] realized they’re wide open if you have the right equipment. The right equipment, it turns out, is a Game Boy Color.

The shelf labels in question are controlled by a base station with a decidedly non-standard carrier frequency and a proprietary protocol. IR driver chips found in phones are too slow to communicate with these labels, and old PDAs like Palm Pilots, Zauruses, and Pocket PCs only have an IrDA chip. There is one device that has an active development scene and an IR LED connected directly to a CPU pin, though, so [furrtek] started tinkering around with the hardware.

The Game Boy needed to be overclocked to get the right carrier frequency of 1.25 MHz. With a proof of concept already developed on a FPGA board, [furrtek] started coding for the Game Boy, developing an interface that allows him to change the ‘pages’ of these electronic labels, or display customized data on a particular label.

There’s also a much, much more facepalming implication of this build: these electronic labels’ firmware is able to be updated through IR. All [furrtek] needs is the development tools for the uC inside one of these labels.

There’s a great video [furrtek] put together going over this one. Check that out below.

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Using the Raspberry Pi To See Like A Bee

Bee

The Raspberry Pi board camera has a twin brother known as the NoIR camera, a camera without an infrared blocking filter that allows anyone to take some shots of scenes illuminated with ‘invisible’ IR light, investigate the health of plants, and some other cool stuff. The sensor in this camera isn’t just sensitive to IR light – it goes the other way as well, allowing some investigations into the UV spectrum, and showing us what bees and other insects see.

The only problem with examining the UV spectrum with a small camera is that relatively, the camera is much more sensitive to visible and IR than it is to UV. To peer into this strange world, [Oliver] needed a UV pass filter, a filter that only allows UV light through.

By placing the filter between the still life and the camera, [Oliver] was able to shine a deep UV light source and capture the image of a flower in UV. The image above and to the right isn’t what the camera picked up, though – bees cannot see red, so the green channel was shifted to the red, the blue channel to the green, and the UV image was placed where the blue channel once was.

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Black Mirror, Black Hole: Kill Your Television

don't waste your time TV screenWould you believe that some people think the internet is a time waster? Well, not at this particular address of course, but we can think of some other sites that are absolute rabbit holes without so much as a rousing game of croquet at the bottom. If you need help achieving what Tim Ferriss dubbed a Low Information Diet, there are browser extensions that will block your access to sites that keep you from getting things done. [Ivan’s girlfriend] has taken this time management tack seriously and even created a simple web page that states “Don’t Waste Your Time!” that will show if she tries to get to Facebook.

There’s one small problem with all this, and it’s been around for a long time. [Ivan’s girlfriend] still watches TV. Out of love and respect for her goals, he decided to prank her by blocking her TV viewing. In a delightful twist, the TV will display her own web page to her after 30 seconds.

They have digital and analog TVs, so he had to set up both in order to cover his bases. The digital TV is a monitor fed from a set-top box with HDMI out. As the STB can only be controlled via IR remote, [Ivan] used an HDMI switch to change from the STB input to a Raspi that will display the reprimanding web page and play Pink Floyd’s “Time“.

The analog TV took  slightly more doing. He put a Raspi on the AV input, but connected it from the inside so nothing looked suspicious. The Raspi checks the TV status every second and switches to the Pi once the TV is on. Same deal: judgmental web page, Pink Floyd. The beauty part is that both of [Ivan]’s setups also record her reaction; the digital TV uses a dash camera and the analog  uses an Android phone. Check out [Ivan]’s tour of the analog TV Pi after the break.

If you or [Ivan’s girlfriend] need even more time management help, there’s always the roll-your-own-Pomodoro timer.

 

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A Mini Op-Amp Based Line Following Robot

LineRobot

There’s no denying it. Super small robots are just cool. [Pinomelean] has posted an Instructable on how to create a mini line following robot using only analog circuitry. This would make a great demo project to show your friends and family what you’ve been up to.

Analog circuitry can be used instead of a microcontroller for many different applications, and this is one of them. The circuit consists of two op-amps that amplify the output of two phototransistors, which control each motor. This circuit is super simple yet very effective. The mechanical system is also quite cool and well thought out. To keep things simple, the motors drive the wheel treads, rather than directly through an axle. After the build was completed, the device needed to be calibrated by turning potentiometers that control the gain of each op-amp. Once everything is balanced, the robot runs great! See it in action after the break.

While not the smallest line follower we have seen, this robot is quite easy to reproduce. What little robots have you build lately? Send us a tip and let us know!

[via Embedded Lab]

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Modular Arduino Based Infrared Thermometer

IRTemperature

[Brian] started out with a clear and concise goal, “allow a regular human to associate an audible tone with a temperature from an infrared contactless thermometer.” With his latest project, the ESPeri.IRBud, he has achieved this goal.

One of our favorite parts of [Brian’s] post is his BOM. Being able to easily see that the IR temperature sensor costs $26 at DigiKey is unbelievably helpful to readers. This specific sensor was chosen because others have successfully interfaced it with the Arduino. Not having to reinvent the wheel is good thing! For the build, [Brian] decided to hook up the IR temperature sensor to a re-purposed flexible iPhone headset wire. Having used headphone sockets to connect to the sensor and speakers, the actual device is quite modular. Hearing this thing in action is quite cool, it almost sounds like old-school GameBoy music! Check it out after the break.

Have you used an IR temperature sensor in one of your projects? Let us know.

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LED Matrix Mask Will Scare Up Holiday Cheer

[Davide] sent us this fun LED matrix mask he built using an ATMega8 and 74LS595N shift registers. Each of the eyes is an 8×8 LED matrix, and the mouth is made from two 8x8s. [Davide] used a ULN2803A Darlington transistor array to drive the matrices.

When the user steps behind the mask, an IR sensor detects that a face is within range and activates the facial features. The code randomly runs the eye and mouth patterns. If the user starts speaking, a microphone element detects his voice and a separate speaking mouth pattern is executed.

The mask body and stand are découpaged with pages from Dylan Dog comics. [Davide] says he built the mask years ago, but decided to submit it to the 2013 Inverart Art Fair in Milan. As you can probably imagine, the mask has been a big hit with the kids so far. Stick around to see [Davide]’s Santa-fied demonstration after the jump. [Davide] didn’t give us any details on that sweet hat, unfortunately.

If you require a better degree of protection or more LEDs, check out this LED helmet.

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IR Theremin Speaks In Four Voices

infraredTheremin

At the end of every semester, we get a bunch of cool and well-documented student projects from Cornell’s ECE4760 class. [Scott] and [Alex]’s infrared theremin is no exception.

The classic theremin design employs each of the player’s hands as the grounded plate of a variable capacitor in an LC circuit. For the pitch antenna, this circuit is part of the oscillator. For the volume antenna, the hand capacitor detunes another oscillator, changing the attenuation in the amplifier.

[Scott] and [Alex] put a twist on the theremin by using two IR sensors to control volume and pitch. The sensors compute the location of each hand and output a voltage inversely proportional to its distance from the hand. An ATMega1284P converts the signal to an 8-bit binary number for processing. They built four voices into it that are accessible through the push-button switch. The different voices are created with wave combinations and modulation effects. In addition to Classic Theremin, you can play in pure sine, sawtooth, and FM modulation.

If you’re just not that into microcontrollers, you could build this digital IR theremin instead. If you find IR theremins soulless or plebeian, try this theremincello.

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