Peer network using graphing calculators

These calculators are networked together, able to pass information and play games on a multi-screen playing field. All of this is thanks to [Christopher Mitchell's] work on a package called CalcNet. This networking software takes advantage of [Christopher's] shell and GUI for TI calculators called Doors CS. To demonstrate the high reliability and throughput of his network he wrote NetPong, a multi-calculator version of the popular game that you can watch in a clip after the break.
This is definitely an instance where asking ‘why?’ is the wrong question. We’re more interested in the how, a question you can answer for yourself by reading the whitepapers he provided in both of the links above. [Christopher] knows what he’s doing, he proved that with his face-recognizing augmented reality.

DIY Breathalyzer may be the hit of the party

Okay, this may not be saving any lives, but it makes for a fun novelty at your next rager. Most Breathalyzers aim to keep you from driving when you’ve had too many. The Squidalyzer encourages party-goers to drink more and more by treating a high blood-alcohol-content with great fanfare. An Arduino, a gas sensor, and Processing all come together for this hack. A television interface tells you when to blow into a cup which houses the sensor, and gives a reading of what it measures. Blow higher than the last guy and you’ll break the record. Watch the demo after the break to see the fun [Geoff] had with it. And remember, friends don’t let friends solder drunk.

External RAM for an ATmega128

Those who are familiar with Atmel’s line of 8-bit AVR microcontrollers should already know that some of them have support for external RAM. But have you ever actually used this feature? We haven’t. Now you can learn how it’s done by reading through this guide. It touches on all of the hardware, but doesn’t dwell on it. Instead, you’ll get the background you need on how to write to, read from, and test an external module like the one sticking up in the image above. The test routine shows how to make sure everything’s working correctly with your memory mapping before you begin developing firmware around this increased capacity.
[Thanks Spman]

SD activity indicator for Wii

[DeadlyFoez] wanted to know when the SD card in his Nintendo Wii was in use. He built and indicator LED using a PICAXE 08M and added it next to the SD slot. He uses one pin of the microcontroller to monitor the voltage on one pin of the SD card slot. That pin has a specific value when the card is idle, which rises when it’s in use. He didn’t share the details of which pin he’s sampling, or what the magic number from his source code actually represents. But the concept should be enough of a start if you want to do this one yourself. Watch it go blink-ity-blink in the clip after the break.

Home built knitting machine

Wow, we knew it wouldn’t be too long before we would see a fully automated home built knitting machine show up. We recently posted a hack where people were emulating the keyboard input of a commercial knitting machine, and that was pretty awesome, but we knew we would be seeing some hacked together machines soon. [corex37] hasn’t let us down with this beast. It is mainly composed of old printer parts, a couple servos, and a Picaxe 18-x microcontroller. It seems to do a good job right now, but lets hope he keeps going. It would be cool to see it able to change colors like the other one.
[via Make]

The Heinz Automato

[Bill Fienup] and [Barry Kudrowitz]‘s robots, The Automatos, have been leaving a sticky path of destruction all over the internet. Their sole purpose: to crap ketchup. They accomplish this feat by dumping a CO2 cartridge into a ketchup bottle at the push of a button, leading to some pretty awesome results.  While the details are a little sparse it appears that they are using RC cars for the base and a small air gun CO2 cartridge to push the ketchup. The latest version aka the Atuomato 4 appears to be multi-actuated and can shoot more than once for maximum ketchup proliferation. See some videos of it in action after the break.