Year: 2011

FT-2232 Bridges Python And I2C/SPI

November 14, 2011 by 9 Comments

You might already have the hardware on hand to easily interface I2C and SPI devices with Python scripts on your computer. The board seen above is an FT-2232 breakout board. These chips are often used to facilitate JTAG programming via USB, but they have other features that might be useful to you as well. The chip has a Multi-Protocol Synchronous Serial Engine (MPSSE) which can speak the I2C and SPI protocols, you just need to know how to active them in your code.

[Craig] makes this easy with his MPSSE Python wrapper. Simply install his module, and you’ll be able to import all the commands you need. He demonstrates reading the data out of a 1 MB SPI flash memory chip. This could be used for a lot more, including debugging peripherals à la the Bus Pirate, or reprogramming chips to add to your projects (we’re thinking font arrays and sprites for displays, or look-up tables).

If you’re not aware, these FTDI chips were the go-to for USB support for a long time. We’ve got a guide for bit-banging using this hardware. Lately more chips have become available with USB hardware built-in. They’re quite useful and cost-effective, especially with the availability of open-source stacks like the LUFA project.

There’s A Lot Packed Into This BeagleBoard Controlled Rover

November 14, 2011 by 7 Comments

That black box is hiding all kinds of goodies that make this rover a hacking playground. [Andrey] built the device around a BeagleBoard, which offers the processing power and modules that he needed to make the rest of it work.

The control unit shrinks the pilot down to the rover’s size, using a cockpit that has a steering wheel and other controls, and a monitor playing the stream from the camera on the front of the bot. It has a WiFi adapter which allows control via the Internet. The camera, which can be rotated thanks to its servo mounting, feeds the video to the BeagleBoard where it is compressed using the h264 codec (more about that and the cockpit here) to lighten the streaming load. You’ll also find an ultrasonic rangefinder on the front for obstacle avoidance, and a magnetic compass for orientation information. Finally, a GPS bolsters that data, allowing you to plot your adventures on the map.

It’s great, but it will cost you. Material estimates are North of five hundred Euros!

Taking GPS Where No Man Has Gone Before

November 14, 2011 by 24 Comments

[Willem] has a friend that wanted to take a GPS datalogger up an unclimbed mountain the wilds of Kyrgyzstan. The GPS logger built for the expedition made it to the summit of Eggmendueluek, but it didn’t work the whole way up. Since the logger came back to London, [Willem] was able to do a complete teardown and failure analysis.

The data logger was built around a Jeenode with a GPS unit and MicroSD card reader added on. A few breakout boards were made and two of these bad boys were ensconced in water and dust proof enclosures. Powered by four AA batteries, the data loggers were able to handle the rigorous testing of being thrown down a staircase and also the harsh temperatures of London. Things changed in the wilds of Kyrgyzstan, though.

The data retrieved from the mountaineering expedition wasn’t the greatest – a few wires came loose after being thrown into the back of a Russian truck and jostled around. The AA batteries only powered the data loggers for three days, compared to the 12 day battery life in London. There are a few improvements needed for the next trip – some thermal insulation and not using solid core wire – but not that [Willem] has figured out the bugs he’s ready for his friend’s next expedition.

The International Obfuscated C Code Contest Is Back

November 14, 2011 by 13 Comments

The International Obfuscated C Code Contest is back. The stated goals of the IOCCC are to, “Write the most obscure C program, show the importance of programming style (by doing the opposite), stress the preprocessor to the breaking point, and illustrate some subtleties of the C language.” If you think you’re up to the task of abusing your compiler, check out the rules and guidelines for the contest.

There’s nothing quite like having the code for a flight simulator look like a plane, or calculating pi by measuring the area of C code. The submissions to the IOCCC are classic hacks; very clever things that shouldn’t work, but do despite themselves.

There hasn’t been an IOCCC competition since 2006, and no one knows if it will be around next year. We’ve already seen a few potential entries for this year, like piping chars into /dev/audio to generate a song and hyperlinks all the way down. If you’ve got something you’re working on, feel free to send it in.

via /.

Insane Macro Photography Rig

November 14, 2011 by 11 Comments

[fotoopa] just put up a Flikr build log of his 3D macro photography rig he uses to take pictures of insects in flight. Outside Hollywood or National Geographic, we’ve never seen a crazier photography rig.

[fotoopa]’s build is based around two cameras – a Nikon D200 and D300. These cameras are pointed towards the subject insect with two mirrors allowing for a nice stereo separation for 3D images. Of course, the trouble is snapping the picture when an insect flies in front of the rig.

For shutter control, [fotoopa] used two IR laser pointers pointed where the two cameras converge. A photodiode in a lens above the rig detects this IR dot and triggers the shutters. To speed up the horribly slow 50ms shutters on the Nikons, a high-speed shutter was added so the image is captured within 3ms.

[fotoopa]’s 2011 rig took things down a notch; this year he’s only working with one camera. Even though he didn’t get any 3D images this year, the skill in making such an awesome rig is impressive.

via (diyphotraphy.net)

Half-tone CNC With Man-powered Z Axis

November 14, 2011 by 10 Comments

We think this is an intriguing take on half-tone art. It’s a CNC machine that uses an Arduino and two stepper motors to draw on a paper-covered drum. But you’re not just going to set it and forget it. To simplify the device, the Z-axis is not mechanized, but requires the dexterous opposing digit of a person to actuate.

The first prototype used a frame cut from plywood, but the developers moved to some attractive laser-cut Lexan for the final version. The rotating drum was inspired by observing the off-set printing process. It greatly simplifies the build when compared to a flat CNC bed. But including a Z-axis solution that could account for differently sized dots really opens a can of worms. Because of this, the choice was made not to automate that task, but to leave it up to the user. A clickable Sharpie does the marking. When the pen is in place, you click the plunger to hold the felt tip against the paper until a dot of the appropriate size has leeched onto the paper.

It’s not a bad solution to the problem. Especially if you don’t have the high-end milling equipment necessary to do this on a piece of plywood.

[Thanks Dron]

Spaduino Heats Up A Used Hot-tub

November 14, 2011 by 38 Comments

[Ryan] and the roomies decided that a hot tub was just what they needed to spice up the place. They hit Craig’s List and found one for the right price. After acquisition and setup they were pleased to find that the jets and pump worked great. But you’re not going to want to stick as much as your big toe into this ice-cold cryogenics experiment. Some poking around in the control system exposed the dead relays which are responsible for switching the heater. Instead of swapping the parts, [Ryan] began building a control system that will replace the twenty-year-old original.

The heating element still works, but it’s rated at 5.5 kW and here’s no way to automatically switch it on and off. [Ryan] found a 60 Amp solid state relay which can handle the load, and plays nicely with his Arduino. Initial tests got the tub up and running again. Obviously you want the tub to maintain temperature and so a thermistor was added to take readings from the heater core. There’s also a potentiometer to adjust the temperature, and an LCD screen to show the current settings. But [Ryan] hopes to add more features over time, like incorporating jet control, and adding wireless communications via an Xbee module.