Raspi Ambilight Integrated In A 19″ Rack Packs Lots Of Peripherals

August 2, 2014 by Mathieu Stephan 6 Comments

Ambilight systems create light effects around your monitor that correspond to the video content you’re playing. [Sébastien] just build his (French translated to English, original here) and embedded all the elements in a 19 inch rack he bought from Farnell.

As most ambilight systems we’ve covered over the years the HDMI signal is first split in two, one being sent to his monitor while the other is converted into a S-Video signal. The latter is then captured with a STK1160 stick connected to a Raspberry Pi. A python script using the OpenCV library is in charge of extracting the frames pixels and figuring out what colors should be sent to the SPI connected LPD8806 LEDs. A nice web interface also allows to drive the LEDs from any platform connected to his local network. Finally, a standard HD44780 LCD and an infrared receiver are connected to the raspberry, allowing [Sébastien] to control and monitor his platform. Funny thing: he also had to use two relays to power cycle his HDMI splitter and converter as they often crash. You can check out a demonstration video from a previous revision after the break.

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A Real Raspberry Pi Clone (Not ‘Inspired By’)

July 30, 2014 by Brian Benchoff 63 Comments

odroid A few years ago, Broadcom had a pretty nice chip – the BCM2835 – that could do 1080 video, had fairly powerful graphics performance, run a *nix at a good click, and was fairly cheap. A Broadcom employee thought, “why don’t we build an educational computer with this” and the Raspberry Pi was born. Since then, Broadcom has kept that chip to themselves, funneling all of them into what has become a very vibrant platform for education, tinkering, and any other project that could use a small Linux board. Recently, Broadcom has started to sell the BCM2835 to anyone who has the cash and from the looks of it, real Raspberry Pi clones are starting to make their way into the marketplace.

Other Raspberry Pi clone boards out there like the Banana Pi and the HummingBoard don’t use the same BCM2835 found in the Raspi and the new Odroid. The new board also has the same 26 pin GPIO expansion socket, and runs the same binaries as the Raspberry P;. It is a clone in every sense, with a slightly different form factor geared towards very tiny, portable, and battery-powered use cases.

Unlike the official Raspberry Pi Compute Module, the Odroid isn’t meant to be used as a system on module, shoved into any product that needs a fast-ish ARM core without needing engineers to actually design a circuit with an ARM. The Odroid is a cut-down, extremely minimalist version of the Raspi, perfect for any project where space is at a premium.

There are a few interesting features included on the Odroid: there’s an on-board battery connector, a real-time clock on the board, and more of the BCM2835 GPIOs are exposed (although not the same ones as the upgraded RPi Model B+). There’s no Ethernet, but odds are if you’re building something that’s battery-powered, you won’t need that anyway.

As far as price goes, you can pick one of these Odroids up for $30 USD, with $9 shipping from South Korea. That’s pretty comparable to the price of a real Raspberry Pi, but if the features in the Odroid are worth it to you, it might be a worthwhile clone.

ASTROGUN Is Like Asteroids On Steroids

July 27, 2014 by Rick Osgood 50 Comments

Astrogun

As the Jerusalem mini Makerfaire approached, [Avishay] had to come up with something to build. His final project is something he calls ASTROGUN. The ASTROGUN is a sort of augmented reality game that has the player attempting to blast quickly approaching asteroids before being hit.

It’s definitely reminiscent of the arcade classic, Asteroids. The primary difference is that the player has no space ship and does not move through space. Instead, the player has a first person view and can rotate 360 degrees and look up and down. The radar screen in the corner will give you a rough idea of where the asteroids are coming from. Then it’s up to you to actually locate them and blast them into oblivion before they destroy you.

The game is built around a Raspberry Pi computer. This acts as the brains of the operation. The Pi interfaces with an MPU-9150 inertial measurement unit (IMU). You commonly see IMU’s used in drones to help them keep their orientation. In this case, [Avishay] is using it to track the motion and orientation of the blaster. He claims nine degrees of freedom with this setup.

The Pi generates the graphics and sends the output to a small, high-brightness LCD screen. The screen is mounted perpendicular to the player’s view so the screen is facing “up”. There is a small piece of beam splitting glass mounted above the display at approximately a 45 degree angle. This is a special kind of glass that is partially reflective and partially translucent. The result is that the player sees the real-world background coming through the glass, with the digital graphics overlaid on top of that. It’s similar to some heads-up display technologies.

All of the electronics fit either inside or mounted around a toy gun. The display system was attached with a custom-made fiberglass mount. The code appears to be available via Github. Be sure to watch the video of the system in action below. Continue reading “ASTROGUN Is Like Asteroids On Steroids” →

Adding GPIOs To The Raspberry Pi With The Camera Interface

July 24, 2014 by Brian Benchoff 9 Comments

GPIOs

The Raspberry Pi Model B+ was just released, and now everyone who picks one of those up has a few more GPIO pins to play around with. For the millions of people with the two-year-old version of the Pi, we’re still stuck with the same old, same old: 17 GPIOs on the big header, and that’s about it as far as toggling pins goes.

The Broadcom SoC on the Pi has far more GPIO pins than are broken out on the large header, and a few of those go to the CSI camera interface. These GPIOs can be broken out with a few flat cables (Portuguese, Google Translatrix), giving you four more GPIOs, and this technique can also be used with the new, expanded Model B+.

The CSI camera connector has two I²C lines that go directly to the camera, controllable in Linux as GPIO0 and GPIO1. There are two more GPIO connectors on the CSI connector controllable as GPIO5 and GPIO21. By carefully slicing and soldering wires to a flat cable, these GPIO lines can be broken out onto a breadboard.

There’s a video below demonstrating these GPIO lines being used to control a few LEDs. Of course, anything that is possible with a normal Raspi GPIO is possible with the CSI connector GPIO lines.

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Smart Hat Puts Your Head In The Game

July 22, 2014 by Will Sweatman 8 Comments

man wearing a diy head mounted display

[Arvind] has dropped his hat in the game of head mounted displays. With Google Glass pushing $1,500, it’s only natural for hackers to make a cheaper alternative. [Avind’s] $80 version might not be pretty, but it gets the job done.

Using a Raspberry Pi loaded with speech recognition software, a webcam, 2.5 inch LCD display and a handful of other parts, [Arvind’s] hat mounted display allows him to view email, Google Maps, videos or just about anything he wants.

An aspheric loupe magnifier lens lets him see the display even though it sits around 5cm from his eye. No outside light is allowed in. Only the guts of the webcam were used to give him the video and microphone. We’ve seen other head mounted displays before, and this one adds to the growing collection. Be sure to check out [Arvinds] site for a tutorial on how to build your own, and catch a video of it in action after the break.

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I’m Sorry Dave, I’m Afraid I Can’t Do That

July 20, 2014 by James Hobson 51 Comments

HAL9000 Personal Computer

“Let me put it this way, Mr Amer. The 9000 series is the most reliable computer ever made. No 9000 computer has ever made a mistake or distorted information. We are all, by any practical definition of the words, foolproof and incapable of error. “

With that in mind, who wouldn’t want a HAL 9000 personal computer at home? For his latest project, [Eduardo Zola] brings us a very realistic Raspberry Pi powered HAL 9000, complete with an all seeing eye.

In case you’re not familiar (boo!) HAL 9000 is a character from 2001: a Space Odyssey. His name is an acronym for a Heuristically programmed ALgorithmic sentient computer who is responsible for controlling the Discovery One spacecraft, and well, he goes crazy.

[Eduardo] has built this replica out of wood, a bit of paint, a Raspberry Pi, a speaker, webcam and a beautiful red all-seeing-eye, lit with LEDs. It’s a rather fitting entry to our Hackaday Prize contest.

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Building The Slimmest Raspi

July 17, 2014 by Brian Benchoff 28 Comments

slim_pi

[Colin], AKA [Domipheus], was working on a project to monitor a thermostat with a wall mounted Raspberry Pi and a touchscreen. Simple enough, but the Pi has a problem: The plugs are all around the perimeter of the board, and with a TFT touch screen shield, it’s a bit too thick to be wall mounted. What followed is a hack in the purest sense: [Domipheus] removed and relocated components on the Pi until the entire Pi/display stack was just a hair over 10mm tall.

A Raspberry Pi Model A was used for this build, meaning the Ethernet jack was gone, and there was only a single USB port to deal with. Still, the highest components – the RCA and audio jacks – were too tall and needed to be removed; they weren’t going to be used anyway.

After these components were gone, [Domipheus] turned his attention to the next tallest parts on the board: fuses, caps, and the HDMI port. For fear of damaging the surrounding components when removing the HDMI connector the right way, this part was simply hacked off. The large tantalum cap near the USB power connector was removed (it’s just a filter cap) and the large protection diode was moved elsewhere.

Slimming down a Pi is no good without a display, and for that [Domipheus] used this touchscreen thing from Adafruit. Things got a little complicated when the project required the ability to remove the LCD, but you can do amazing things with a DIP socket and a file.

The end result is a Raspberry Pi with touchscreen display that’s just a smidgen thicker than a CD case. It’ll fit right up against a wall in its repurposed enclosure, and the end result looks very professional.

[Thanks Luke via reddit]