Another Switch Mode Regulator Swap For The Raspberry Pi

July 7, 2012 by Mike Szczys 32 Comments

[Karl Lunt] is working to slim the Raspberry Pi current draw as much as possible. The first step in his journey was to replace the linear voltage regulator with this switch mode version. It’s a step-down voltage regulator circuit with a tiny footprint and a matching price tag (about $10) made by Pololu. It’s small enough to be mounted in the empty space between the LCD ribbon connector and the main processor.

The project was based on the hack we saw at the end of June. But we give much more credit to [Karl] for removing the old part in a safer way. He clipped the two small leads on the bottom of the old part, then used a beefy iron to sufficiently heat the large pad before removing the body of it. With the old part out of the way it’s just a matter of connecting the three wires in the right configuration.

This cut consumption by about 50 mA. He’s hoping to do more by removing the on-board LEDs. His goal is a draw of under 250 mA in order to make it last a reasonable amount of time when running from batteries.

OpenGL On The Raspi

July 6, 2012 by Brian Benchoff 8 Comments

Perhaps we’ve been concentrating too much on the hardware side of the Raspberry Pi. Sure, connecting the Raspi to the outside world through GPIO pins is cool, but let’s not forget we’re dealing with a full-fledged Linux box here. [chris] is doing his best to keep us in check with by bringing the power of OpenGL graphics to the Raspberry Pi.

Previously, OpenGL ES was only available for xorg but [chris] successfully added support for Raspbian. There’s a great physics demo [chris] put together showing off 128 spheres and cubes bouncing around a plane.

Right now, [chris] is looking for people to contribute samples and tutorials for making accelerated 3D graphics on the Raspi. You can grab all the code over at [chris]’ Git and contact him over on the Raspberry Pi forums if you’d like to help out.

As with any graphics demo, check out the videos after the break.

Continue reading “OpenGL On The Raspi” →

Acrylic RPi Case You Can Make Without A CNC Machine

July 6, 2012 by Mike Szczys 15 Comments

[Simon Inns] is showing off the Raspberry Pi case which he built out of acrylic. It provides a lot more protection than a flimsy film case, but it is also a little bit more involved to fabricate. No, this doesn’t need to be laser cut, but to get the nice edges [Simon] used a band saw which many don’t already have in their shop. Ask around, or poke your head in at the local Hackerspace. It only takes a few minutes to cut out the parts.

It sounds like either 8mm or 6mm acrylic will work for this project. Aluminum pipe serves as a spacer to keep the two main sheets in place. The RPi board itself is held in position by a few well-place acrylic chunks super glued in place. You can see the entire build process, including rounding cut edges with a torch, in his video embedded after the break.

Continue reading “Acrylic RPi Case You Can Make Without A CNC Machine” →

Raspberry Pi Prototyping Boards Available At Adafruit

July 5, 2012 by Brian Benchoff 24 Comments

If you’re one of the lucky few with a Raspberry Pi, adafruit has two things you might be interested in if you’re into GPIO hacking.

First up is the Pi Cobbler kit. It’s a 2×13 ribbon cable with a breakout PCB ready to attach to a solderless breadboard; perfect for playing around with (or cobbling together… get it?) the GPIO pins on your Raspi.

Next up is the Pi Plate kit that comes complete with enough perfboard space, screw terminals, and female headers to kill a yak. All the GPIO, I2C, and SPI pins are broken out on the Pi Plate, making it very easy to prototype a semi-permanent Raspi circuit.

They might be just prototyping boards now, but we expect these Pi Plates to quickly evolve into a truly useful device with the addition of a few level shifters, port expanders and a few ADCs and DAC thrown in for good measure. If you’re still on the fence and thinking about buying a Raspi, I ordered one last week from element14 and now have an expected ship date of November 5th. These things must be really popular.

Flimsy Pi Case Still Provides A Level Of Protection

July 5, 2012 by Mike Szczys 14 Comments

This flimsy case isn’t going to protect your Raspberry Pi if you knock it off the workbench. It will provide a level of protection against shorting out from contact with metal objects, or from liquids spilled in the near vicinity. [CGPatterson] ended up making this case from a single sheet of transparency film.

The project is basically papercraft. He started with the dimensions published on the Raspberry Pi FAQ, which turned out to be wrong. Not having a caliper available to help with the precision of the measurements, he grabbed his ruler and did the best he could. The first two cases were a poor fit, but as you can see the third is like a glove. Luckily you don’t have to go through this same trial and error as he release the design. Both A4 and US Letter sized PDFs are available for download. Print them out on the transparency, cut along the lines, apply transparent double-sided tape to the tabs and you’re in business. If you wish to alter the design he has also posted the SVG source he made in Inkscape.

This is certainly a good option for those of us without the ability to produce laser cut parts.

Interfacing SNES Controllers With Your Raspberry Pi

July 5, 2012 by Mike Szczys 12 Comments

This lovely set of wires lets [Florian] connect stock Super Nintendo controllers to his Raspberry Pi. The IDC connector in the upper left plugs into the GPIO header on the RPi rather than going the route of using an intermediary USB converter.

The setup lets you connect two controllers at once, so you’ll have no trouble going head-to-head on Mario Kart as seen in the clip after the break. The ports themselves were pulled from a pair of SNES extension cables. Since button signals are pushed to the console via a shift register there’s just five wires needed for each (voltage, ground, data, clock, and latch). As far was we know the Raspberry Pi pins are not 5V tolerant so you probably want to add some level conversion to this circuit if you build it yourself.

[Florian] wrote a C program which shifts in data from the controllers and converts it to HID keyboard inputs. This should make it extremely flexible when it comes to emulator setup, and using the technique for different styles of controllers should also be pretty easy.

Continue reading “Interfacing SNES Controllers With Your Raspberry Pi” →

Ti Chronos Watch Controls Raspberry Pi

July 3, 2012 by Mike Szczys 9 Comments

[Mike Field] was working on interfacing his TI Chronos eZ430 watch with the Raspberry Pi. As things were going pretty well, he took a side-trip from his intended hack and implemented watch-based control for an RPi audio player.

It really comes as no surprise that this is possible, and even easy. After all, the RPi board has native USB capability for hosting the watch‘s RF dongle, and it’s running Linux which we know already works well with the Chronos platform. But we still love the thought of having automation controls strapped to our wrist!

mpg321 is the audio playback program used for this hack. It plays MP3 files using ALSA for sound, which does have a few hiccups on the RPi. [Mike] found workarounds and included them in the C program he uses to gather everything into one nice code package. Control depends on keypresses sent from the watch (meant for use with PowerPoint) which are translated by his code and pushed to the audio/mp3 programs.