Putting QR codes in copper

April 12, 2012 By Leave a Comment

Former Hackaday contributor [mikeysklar] has been trying to etch a QR code into a sheet of copper. Although his phone can’t read the CuR codes he’s made so far, he’s still made an impressive piece of milled copper.

The biggest problem [mikey] ran into is getting Inkscape to generate proper cnc tool paths instead of just tracing a bitmap image. He’s got the CNC part of his build under control, but he still can’t find a QR code reader that will register his work.

We’re no stranger to QR codes here at Hack a Day, and it’s very possible the only thing that could be stopping [mikey]’s QR code from being read by a phone is the contrast of the image. We’re thinking a little bit of printer’s ink forced into the non-copper part of the PCB would make the QR code register. Since [mikey] already has a very nice negative etching of his QR code, he could easily use his new board as a printing plate, making infinite paper copies of his copper-based QR code.

If you’ve got any ideas on how [mikey] can get his QR code working, post them in the comments.

Filed Under: cnc hacks Tagged With: , , ,

Accelerometer-based game control using an iOS device courtesy of HTML5

March 26, 2012 By Leave a Comment

This game of Space Invaders is played by tilting your iPhone to the left or right. It’s a demonstration of HTML5 used to link devices in-browser. The only setup that’s required is for the base device to load up a webpage, then the control device scans a QR code (or just types in a link) to connect with the game. You can give it a try right now if you want.

It only works with iOS devices but we believe that’s because mobile Safari has the ability to poll accelerometer data and other browsers do not. If this was using on-screen buttons rather than the tilt controls it would work on any device that implements HTML5. The connection is facilitated by Node.js and Socket.IO. The QR code that is generated by the host machine’s page includes a unique ID which allows the control device to link with it. Once loaded, commands from the controller are sent via Socket.IO to the node on the host machine.

As with this HTML5-based sensor data application, we think this method is important because it allows control without the need for a standalone application. We’re hoping to see a lot of this in embedded projects in the future. By serving data to a smart phone or other device you remove to need for a physical user interface in your projects, which means you can make great things while spending less.

[via Reddit]

Filed Under: cellphones hacks, iphone hacks Tagged With: , , , ,

RFID playlists plus a QR code concept

March 15, 2012 By Leave a Comment

Here’s another audio playback hack that uses physical tokens to choose what you’re listening to. It uses Touchatag RFID hardware to control iTunes. The concept is very similar to the standalone Arduino jukebox we saw on Wednesday except this one interfaces with your computer and the tags select entire albums instead of just one song. A shell script processes the incoming tag ID from the reader, populates a playlist with all the tracks from the associated album, then executes an AppleScript to launch that playlist. Check out the short demo after the break.

But what really caught our eye is the QR-code reader concept which [Janis] hopes to implement at some point in the future. The computer side of things doesn’t need to be changed, but we love the challenge of putting together an FPGA-based camera to recognize and decode the QR image. Looks like a perfect use for that $10 camera module and it’s FPGA driver!

[Read more…]

Filed Under: digital audio hacks Tagged With: , , , ,