ATX Raspi Is A Smart Power Source For Raspberry Pi

May 19, 2013 by 55 Comments

One aspect of the Raspberry Pi that has always challenged us is the power supply. It was a great idea to power the board from a standard micro-USB port because economy of scale makes phone chargers (even in the 1A range necessary for stable operation of the RPi) cheap and easy to acquire. The thing we miss is the ability to power the device on and off using the built-in hardware. The quandary has given rise to many different solutions, and the ATX Raspbi smart PSU is one of the better ones we’ve come across. It’s a nicely packaged take on the PIC-based version we saw earlier in the year.

The device is a small PCB that acts bridge between the micro-USB power supply and the RPi board. It offers several breakout headers, one of which is used for a power button. The button is monitored by a microcontroller that switches the on-board relay accordingly. But it won’t just kill the power when you want to shut down. It first signals one of the RPi GPIO pins, causing the OS to execute a shutdown script. It then monitors the RPi for the shutdown tasks to finish before cutting the power.

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Wireless Microcontroller/PC Interface For $3

May 19, 2013 by 48 Comments

uc

Sending data from a microcontroller to a PC usually requires some sort of serial connection, either through fiddly on-chip USB, FTDI chips, or expensive radio ICs. [Scott] didn’t want to deal with this when creating a network of wireless temperature sensors, so he hacked up a few cheap 433 MHz radio transmitters and receivers to transmit data to a PC for about $3.

After sensor data is collected on a microcontroller and sent over radio, there’s still the issue of getting it into a PC. For this, [Scott] piped the data into the microphone port of a cheap USB sound card. We’ve seen this trick before both in the world of microcontrollers and loading programs onto a Commodore 64 via a cassette interface.

Once the data is sent into the sound card, it’s decoded with a a small Python app. Given the range and quality of the RF transmitters and receivers  [Scott] says it’s not an extremely reliable way to send data to a PC. It is cheap, though, and if you need to read sensors wirelessly on a budget, it’s hard to do much better.

Check out [Scott]’s demo of his creation below.

[youtube=http://www.youtube.com/watch?v=GJHFldPwZvM&w=580]

Controlling A Terminal With Google Voice

May 19, 2013 by 17 Comments

sms

For how awesome Google Voice is, we’re surprised we haven’t seen this before. [Steve] is using Google Voice to run commands on just about any Linux box.

Google Voice doesn’t have an official API, and existing unofficial APIs weren’t up to snuff for [Steve]’s project. He ended up writing his own that checks his unread message inbox every minute and looks for new text messages beginning with the phrase, ‘Cmd’. If a series of checks pass – the text coming from a known phone number and a proper terminal command – the command runs and sends the a text back indicating success or failure.

While [Steve] probably won’t be playing nethack or Zork via SMS anytime soon, we can see this being very useful for a Raspi home automation task. Just send a text message and a properly configured Linux box can open your garage door, turn on the lights, or even start a webcam.

FPGA Plays Mario Like A Champ

May 19, 2013 by 7 Comments

fpga-controls-mario-bros

This isn’t an FPGA emulating Mario Bros., it’s an FPGA playing the game by analyzing the video and sending controller commands. It’s a final project for an engineering course. The ECE5760 Advanced FPGA course over at Cornell University that always provides entertainment for us every time the final projects are due.

Developed by team members [Jeremy Blum], [Jason Wright], and [Sima Mitra], the video parsing is a hack. To get things working they converted the NES’s 240p video signal to VGA. This resulted in a rolling frame show in the demo video. It also messes with the aspect ratio and causes a few other headaches but the FPGA still manages to interpret the image correctly.

Look closely at the screen capture above and you’ll see some stuff that shouldn’t be there. The team developed a set of tests used to determine obstacles in Mario’s way. The red lines signify blocks he will have to jump over. This also works for pits that he needs to avoid, with a different set of tests to detect moving enemies. Once it knows what to do the FPGA emulates the controller signals necessary, pushing them to the vintage gaming console to see him safely to the end of the first level.

We think this is more hard-core than some other autonomous Mario playing hacks just because it patches into the original console hardware instead of using an emulator.

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Robot Air Hockey Championship As A Final Project

May 18, 2013 by 17 Comments

clemson-air-hockey-robots

My final project is build a robot that plays air hockey? Where do I sign up? Apparently you get yourself a seat in ECE496 at Clemson University. They have been using the concept as a final project for at least a couple of years. [Abe Froman] was on the winning design team this year and he’s showing off his robot and some winning games it played.

His robot is in the foreground. It uses a right-angle PVC joint to hold the paddle. The fitting is attached to a rack and pinion that drives it forward and back. The entire assembly is mounted on a rotating rig. Take a look at some of its opponents that use more of a plotter-type arm. Those offerings have too much play in the joints which at times causes the thing to miss.

Chances are good that once you get a job you won’t be asked to do things for the company unless they are money makers. Sure, there are a few notable exceptions,  but since you’re playing to go to school we really appreciate the professors making the learning as enjoyable as possible before you have to get serious (and maybe even wear a tie!).

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Just Put Your Lips Together To Turn On A Lamp

May 18, 2013 by 14 Comments

whistler-lamp-control

The inlaid image is a controller board which [Limpkin] developed to add whistle control as a home automation option. It has an effective range of around fifteen feet and does a good job of detecting whistles from many different people. Here is one of the test subjects (captured with a hidden camera) whistling to the white LED lamp in order to switch it on.

The board is quite small. [Limpkin] holds it up in the beginning of his test video, which gives a good sense of scale. One end has a barrel jack through which the board gets power. The other end has a two conductor screw terminal which is used for switch your devices. An N-channel MOSFET protects the circuit when a heavy external load is connected. It is capable of driving a respectable 90 watts. If you’re looking to switch mains rated devices you’ll need to bring your own relay to the party.

Audio processing is handled by the Freescale ARM Cortex M4 chip at the center of the board. The Serial Wire Debug (SWD) clock and data pins are both broken out to solder pads so the thing is hackable. [Limpkin] posted the schematic, gerbers, and a code template. But he didn’t release the algorithms he uses for processing so if you want to make this at home you’ll need to figure that out for yourself. If you need help you should check out this whistle-based remote control.

http://www.youtube.com/watch?v=1eIxAMKNphw

Dermal Implants Means Strapless Watch

May 18, 2013 by 111 Comments

dermal

Google Glass is a year or so out, and even after that we’re still looking at about five years until we’re all upgraded at the behest of our robotic overlords. [justurn] simply can’t wait, so he decided to submit to the cybermen early with his Android-controlled wristwatch attached with dermal implants.

[justurn]’s got the inspiration for his project from this earlier Hackaday post involving dermal implants and an iPod nano. The iPod nano doesn’t have a whole lot of functionality, though, but the Sony SmartWatch does, and without the inevitable accusations of fanboyism.

To prep his arm for the hardware upgrade, [justurn] had four titanium dermal anchors placed in his wrist. After letting his anchors heal for a few months, [justurn] installed very strong neo magnets in the bases for his anchors and the clip for the SmartWatch’s strap.

The result is a magnetically mounted, Android-controlled watch semi-permanently attached to [justurn] at the wrist. We love it too.