Hacking A Reader For Medical Test Strips

December 13, 2013 by Brian Benchoff 7 Comments

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[Rahul] works at a startup that produces cutting edge diagnostic test cards. These simple cards can test for enzymes, antibodies, and diseases quickly and easily. For one test, this greatly speeds up the process of testing and diagnosis, but since these tests can now be administered en masse, health services the world over now have the problem of reading, categorizing, and logging thousands of these diagnostic test cards.

The normal solution to this problem is a dedicated card scanner, but these cost tens of thousands of dollars. At a 24-hour hackathon, [Rahul] decided to bring down the cost of the card scanners by whipping up his own, built from a CD drive and an Arduino.

The card [Rahul] used, an A1c card that tests for glucose bound to hemoglobin, has a few lines on the card that fluoresce with different intensify depending on the test results. This can be easily read with a photodiode connected to an Arduino. The mechanical part of the build consisted of an old CD drive with a 3D printed test strip adapter. Operation is very simple – just put the test strip in the test strip holder, press a button, and the results of the test are transmitted over Bluetooth.

Not only is [Rahul]’s build extremely simple, it’s also extremely useful and was enough to net him the ‘Most Innovative Project’ prize at the hackathon in his native Singapore.

Portable Musical Stairs

December 13, 2013 by James Hobson 8 Comments

[Amir] recently finished a pretty cool project — Portable Musical Stairs! He designed and built it so it could be temporarily installed in schools for musical therapy sessions with autistic children — a fun activity for all ages!

The system utilizes lasers and photo sensors that come with a built in digital output with a sensitivity potentiometer, which makes it super easy for the Arduino Leonardo to interpret. The reason they are using 2 by 4’s for the system is because of the width of the stairs. At 1.75m across, a laser misaligned by only 1 degree results in it being about 3cm off!

On the software end of things, the Arduino acts as a HID input to the computer to create the sounds. [Amir] has put together a free sound sampler on his website makeysoundy.com, and we must say, it’s pretty fun! You can assign notes to different keys, which makes it super easy to make a similar project to this!

Stick around after the break to see the stairs in action!

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Finally, An Animated GIF Light Painter

December 12, 2013 by Brian Benchoff 6 Comments

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Light painting, or taking a picture of a moving RGB LED strip with a very long exposure, is the application du jour of Arduinos, photography, and bright, glowey, colorful things. Hackaday alumnus [Phil Burgess] has come up with the best tutorial for light painting we’ve seen. It’s such a good setup, it can be used to create animated .gifs using multiple camera exposures.

The build uses an Arduino Uno, SD card shield, and Adafruit’s new NeoPixel strip with 144 RGB LEDs per meter. Despite a potentially huge mess of wires for this project, [Phil] kept everything very, very neat. He’s using an Altoids case for the ‘duino, an 8 AA-cell battery holder and 3A UBEC for the power, and a wooden frame made out of pine trim.

Part of the art of light painting involves a lot of luck, exponentially so if you’re trying to make a light painted animated .gif. To solve this problem, [Phil] came up with a very clever solution: using a rotary encoder attached to a bicycle. With the rotary encoder pressed up against the wheel of a bike, [Phil] can get a very precise measurement of where the light strip is along one dimension, to ensure the right pixels are lit up at the right time and in the right place.

It’s a wonderful build, and if Santa brings you some gift certificates to your favorite electronics retailer, we couldn’t think of a better way to bring animated .gifs into the real world.

8-Track Tapes As A Storage Medium

December 10, 2013 by Brian Benchoff 42 Comments

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Before [Woz] created the elegant Disk II interface for the Apple II, and before Commodore brute-forced the creation of the C64 5 1/4″ drive, just about every home computer used cassette tapes for storage. Cassette tapes, mind you, not 8-track tapes. [Alec] thought this was a gross oversight of late 1970s engineers, so he built a 8-track tape drive.

This actually isn’t the first instance of using 8-tracks to store data on a computer. The Compucolor 8001 had a dual external 8-track drive, and the Exidy Sorcerer had a tape drive built in to the ‘the keyboard is the computer’ form factor. It should be noted that nearly no one has heard about these two computers – the Compucolor sold about 25 units, for example – so we’ll just let that be a testament to the success of 8-track tape drives.

[Alec] installed an 8-track drive inside an old external SCSI hard drive enclosure. Inside is an Arduino that controls the track select, tape insertion and end of tape signals. Data is encoded with DTMF with an FSK encoding, just like the proper cassette data tapes of the early days.

On the computer side of things, [Alec] is using a simple UNIX-style, pipe-based I/O. By encoding four bits on each track, he’s able to put an entire byte on two stereo tracks. The read/write speed is terribly slow – from the video after the break, we’re assuming [Alec] is running his tape drive right around 100 bits/second – much slower than actually typing in data. This is probably a problem with the 40-year-old 8-track tape he’s using, but as a proof of concept it’s not too bad.

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The $40 X86 Arduino

December 9, 2013 by Brian Benchoff 87 Comments

Every week the Hackaday tip line receives an email about a new dev board. The current trend is towards ARM devices, and only once have we seen an x86-based device. Today that count went up to two. It’s called the 86Duino and stuffs an old Pentium II-class machine capable of running DOS, Windows, and Linux into the space of an Arduino,

The 86Duino Zero features, of course, an x86 Vortex86EX processor running at 300 MHz. This board also features 128 MB of RAM, 8MB of Flash and the usual compliment of Arduino pins in a Leonardo-compatible layout. Also on the SoC is a PCIE bus, Ethernet, a USB 2.0 host, and an SD card. There’s a lot of stuff on this board for such a small size.

Compared to the gigahertz-fast ARM boards around, the 86Duino isn’t really that fast, but that’s not the point. There’s obviously a market for extremely tiny x86 boards out there as evidenced by the Intel Galileo, and this board is $30 cheaper than the Intel offering.

There’s no video out on this board, so someone will have to figure out how to attach a graphics card to the PCIE connector before we build a miniaturized old school DOS gaming rig. Still it’s a very neat piece of hardware. If you need to have it now, here’s a vendor.

Thanks [sohaib] for sending this one in.

Arduino RFID Car Starter

December 8, 2013 by James Hobson 29 Comments

[Pierre] recently bought his first car and decided to make his own RFID electric starter for it!

An Arduino Nano controls two relays which in turn can turn the car on, start it, and turn it off. Instead of adding a button for “push to start” he opted for a 13.56MHz RFID module. Now when he passes his RFID badge across the dash, the car turns on — if it’s held there for over a second, the car starts. Another pass and it will turn off.

His eventual goal is to relocate this circuit closer to the wheel and use an NFC ring to start it! He’s done an amazing job hiding all the components under the trim in his car so far, you can’t tell anything is amiss! Check out the demonstration in the video after the break.

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Will Dance For Bitcoin

December 7, 2013 by Eric Evenchick 6 Comments

It seems that Bitcoin is all over the news nowadays, but the Bitcoin Bot is probably the first robot that will dance for Bitcoins.

[Ryan] at HeatSync Labs in Mesa, AZ, is a fan of the cryptocurrency, and decided to build something to accept it. He discovered that Coinbase, a popular hosted Bitcoin wallet service, has a callback API. This causes Coinbase to fetch a specified URL any time a wallet receives a transaction, and provides information on the transaction in the request. A Python script handles these requests and updates a running count of the BTC balance sent to the robot’s wallet.

On the hardware side, an Arduino with an Ethernet Shield checks the balance. If it has changed, it calls the dance function and the luau girl dances.

The robot sits in the window of the hackerspace, so anyone passing by can read about Bitcoin and make a donation. The source code is on Github, and a video follows after the break.

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