Raspi Mini Laser Engraver

November 23, 2013 by Marsh 9 Comments

If you’ve got a lot of spare parts lying around, you may be able to cobble together your own laser engraver without too much trouble. We’ve already seen small engraver builds that use an Arduino, but [Jeremy] tipped us off to [Xiang Zhai’s] version, which provides an in-depth guide to building one with a Raspberry Pi.

[Xiang] began by opening up two spare DVD writeable drives, salvaging not only their laser diodes but the stepper motors and their accompanying hardware, as well as a handful of small magnets near each diode. To assemble the laser, he sourced an inexpensive laser diode module from eBay and used a vise to push the diode into the head of the housing. With the laser snugly in place and the appropriate connecting wires soldered on, [Xiang] whipped up a laser driver circuit, which the Raspi will later control. [Xiang] worked out the stepper motors’ configuration by following [Groover’s] engraver build-(we featured it a few years back)-attaching the plate that holds the material to be engraved onto one axis and the laser assembly to the other.

Check out [Xiang’s] project blog for details explaining the h-bridge circuits as well as the Python code for the Raspi. As always, if you’re attempting any build involving a laser, please use all necessary precautions! And if you need more information on using DVD burners for their diodes, check out this hack from earlier in the summer

Raspis And Arduinos For FM Broadcast Streaming

November 20, 2013 by Brian Benchoff 74 Comments

radio

The biggest Internet provider in Portugal needed a system to turn FM broadcast stations in Angola, Cabo Verde, and Mozambique into a web stream. Like every good project, the people in charge of the engineering turned to Hackaday staples – Raspberry Pis, Arduinos, and TP-Link routers, all stuffed into an awesome modular rackmount cabinet

Each module in this gigantic rackmount system includes an Arduino, a Raspberry Pi, a Silicon Labs Si4705 FM receiver chip, and a TI USB audio capture chip that allows the Pi to turn the audio out from the radio receiver into an audio stream. All the Pis are connected to a 24 port Ethernet switch and to a separate master Raspi that converts data received from each module into an icecast stream.

The engineering behind each module is pretty impressive – they’re all hot swappable, have remote shutdown capability, and have voltage divider on the backplane to detect where in the rack it’s placed. It’s a very cool piece of engineering and a very cool example of using off-the-shelf hardware to do something that could be much, much harder.

Raspberry Pi Smart TV

November 20, 2013 by James Hobson 25 Comments

[Tony] decided his “smart” LED TV wasn’t quite smart enough. So he stuffed a Raspberry Pi in it.

Upon opening the case of his 40″ Hisense Smart LED TV, he discovered that the logic board actually had two unused USB pads — what luck! He tapped off of them to get 5V @ 500mA to power the Pi… Later on he realized this wasn’t the ideal solution — when the TV turned off, it cut the Pi’s power too. So he pulled out his multimeter and probed the board, this time finding a 5V source that remained on while the unit was plugged in.

Next up was the placement of the Raspberry Pi. The included speakers on this particular TV weren’t that good, and since [Tony] uses a surround sound system anyway, he decided to make use of their space better. Cutting out the grill and removing the whole assembly left him with more than enough room to store the Pi and mount a 3D printed LAN and USB port cover!

He’s running Raspbmc which lends the TV tons of functionality. If you don’t mind voiding your warranty, this is a great hack!

Retropie Gaming Table

November 17, 2013 by James Hobson 4 Comments

rasp pi gaming table

[Jody] just finished the write up on this awesome coffee table he’s been working on. It’s an all-in-one gaming table that makes use of Retropie.

When they finally got rid of the kids’ train-play-set table, they needed something to replace it. Eager to use his new collection of tools (including a 3D printer and a laser cutter!), [Jody] decided to build this thing from scratch. He admits he isn’t a very skilled woodworker, but we think he did an excellent job!

The screen is an old laptop LCD that [Jody] took apart and refitted into the nice wood frame you see above. He’s added speakers with 3D printed grills, and the whole thing turns on and off when the screen is lifted, all thanks to a pantry door switch he installed. In the side compartments he has wireless keyboards, mice, and xBox 360 controllers to play the games with. He and his son have already put many hours into the classic Cave Story, first released back in 2004.

There’s a great build log on his site, so if you’re interested in making your own, check it out!

Google Glass? How About This Home-brew Solution?

November 17, 2013 by James Hobson 22 Comments

[Codeninja] has been sending us some great hacks over the years, and we’ve just learned that his attention has been on building wearable computers lately! He’s currently on his third iteration of a Google Glass-like prototype, which features a motorized element which allows for the retraction of the screen.

There’s not too much info on his blog about them, but we do know he’s using a Raspberry Pi, a few small servos, and a pico LCD screen. Most of the frame is 3D printed, and it also features a hidden camera, accelerometers, and a few environmental sensors.

He’s uploaded an animated gif of the mechanism that moves the display away from his eye, and it looks straight out of some science fiction movie — check it out after break!

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Battery Backup For RasPi Keeps Your Data Safe

November 17, 2013 by Marsh 17 Comments

We’ve all raised a clench fist in anger over lost data, and it’s usually the result of unjustified optimism and lack of planning. [George] shared his solution that prepares for the worst: a circuit that provides backup power to a RasPi and its hard drives. [George’s] Pi setup runs as both an Apple Time Machine server and a website backup server, and a power outage could corrupt the data stored on the Pi’s attached hard drives.

Rather than turn to commercial solutions, however, [George] wanted to take advantage of the Pi’s low power consumption and create an inexpensive custom circuit that would safely and automatically power down the devices upon loss of power. To detect a power failure, the build connects one of the Pi’s GPIOs to an opto-isolator, which—through a zener diode—connects to the 12V wall adapter: though [George] welcomes suggestions for alternative methods of safely identifying a mains power loss. The rest of the circuit serves as a trickle charger for the two attached 9V batteries and as a regulator to supply the correct voltage to the RasPi. Power MOSFETs connected to a GPIO handle the delayed power off.

You can view (and edit!) the circuit online here and find the relevant source code on [George’s] website. If you want to build your own RasPi file server, try cramming all the parts into an old optical drive enclosure.

Real-Life Raspi-Controlled Redstone Lamp

November 16, 2013 by Marsh 2 Comments

redstone-lamp

Minecraft fanatics keep finding impressive ways to bring 8-bit components into the real world, and [Chris Tompson’s] Redstone Lamp Replica is no exception. [Chris] wanted to extend his connection to the game world by not only replicating this block, but also by controlling its light-up effect when an in-game cube is lit.

The lamp is a product of the gang at Hive76, who worked together to develop a quick prototype using the Minecraft Python client pyCraft, an Arduino, a transistor and a temporary papercraft lamp mockup. Hive76 member [Kyle] pitched in to write the plugin for pyCraft, which listens for an on/off message and sets one of the RasPi’s GPIO pins accordingly. The hardware for the actual lamp was designed to smooth out the 8-bit quality into something a bit more precise. The result are laser-cut pieces of MDF with a zebra wood veneer laminated on top. The interior was finished off with amber cathedral glass and then the cube’s sides were glued together. The RasPi, PCB and LEDs fit inside, all snugly affixed together.

Swing over to the Hive76 project page for more details and links to the plugin, and see the video demonstration below. For another Minecraft-inspired real-life project, check out [Bill’s] take on the BatBox.

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