Hacklet 24 – Raspberry Pi Projects

Experimenting with embedded Linux used to mean reformatting an old PC, or buying an expensive dev board. In February of 2012, the Raspberry Pi was released, and it has proven to be a game changing platform. According to the Raspberry Pi Foundation, over 3.8 million boards have been sold. 3.8 million translates into a lot of great projects. This week’s Hacklet focuses on some of the best Raspberry Pi projects on Hackaday.io!

rpfpvWe start with [richardginus] and the RpiFPV (aka Raspberry Pi First Person View) project. [Richardginus]  is trying to build a low latency WiFi streaming camera system for radio-controlled models using a Raspberry Pi and camera. He’s gotten the system down into a respectable 160 milliseconds on the bench, but in the field interference from the 2.4GHz R/C transmitter drives latency way up. To fix this, [Richardginus] is attempting to control the plane over the same WiFi link as the video stream. We’d also recommend checking out some of those “outdated” 72 MHz R/C systems on the used market.

piholgaNext up is [James McDuffie] and his RPi Holga. Inspired by [Peter’s] Holga camera project, [James] has stuffed a Raspberry Pi model A, a camera module, and a WiFi adapter into a Holga camera body. The result looks like a stock Holga.  We saw this camera up close at the Hackaday 10th Anniversary event, and it fooled us – we thought [James] was just a lomography buff. It was only after seeing his pictures that we realized there was a Pi hiding inside that white plastic body! Definitely check out [James’] instructions as he walks through everything from hardware mods to software installation.

cluster2No Raspberry Pi list would be complete without a cluster or two, so we have [Tobias W.] and his 3 Node Raspberry Pi Cluster. The Raspberry Pi makes for a cheap and efficient platform to experiment with cluster computing. [Tobias] did a bit more than just slap a few Pis on a board and call it a day though. He custom machined an aluminum plate to hold his 3 node cluster. This makes wire management a snap. The Pi’s communicate through a four port Ethernet hub and all run from a single power supply. He even added a key switch, just like on the “old iron” mainframes. [Tobias] has been a bit quiet lately, so if you run into him, tell him we’re looking for an update on that cluster!

pivenaFrom [Tim] comes the PIvena, a Raspberry Pi laptop which takes its styling cues from [Bunnie Huang’s] Novena computer.  Pivena is a bit smaller though, with a 7” HDMI LCD connected to the Pi. The case is made from laser cut wood and a few 3D printed parts. Everything else is just standard hardware. [Tim] kept the PIvena’s costs down by using a wooden kickstand to hold up the screen rather than Novena’s pneumatic spring system. The base plate of the PIvena includes a grid of mounting holes just like the Novena. There is also plenty of room for batteries to make this a truly portable machine.  The end result is a slick setup that would look great at any Hackerspace. We hope [Tim] creates an update to support the new Raspberry Pi B+ boards!

Our Raspberry Pi-based alarm clock is chiming the hour, so that’s about it for this episode of the Hacklet! As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Announcing The Trinket Everyday Carry Contest

Now that we’ve recovered from our Munich party and the awarding of The Hackaday Prize, we’re ready to announce our latest contest. We’ve been having a lot of fun with our Trinket Pro boards, both the 10th anniversary edition and the new Hackaday.io branded models.  While we were soldering, compiling, and downloading, a contest idea took root. Trinket Pro really excels when used in small projects, the kind which would fit in a pocket. To that end we’re holding the Trinket Everyday Carry Contest, a showcase for small, pocketable projects which are useful everyday. ‘Useful everyday’ is a bit of a broad term, and we intended it that way. Tools are useful of course , but so are jewelry pieces. It’s all in the eye of the builder and users. We’re sure our readers will take this and run with it, as they have with our previous contests.

There are some great prizes in store for the entrants, including a brand new Rigol DS1054Z  oscilloscope! The top 50 entrants will get custom Trinket Everyday Carry Contest T-shirts. Check out the contest page for a full list. 

submit-project-to-trinket-edcWe know you all love to procrastinate with your entries, so we’re going to be offering a few perks to those who enter early and update often. Each week, we’ll throw all the entrants who have published at least one project log full of details into a drawing for a special prize from The Hackaday Store. To be considered you must officially submit your project which is accomplished through a drop-down list on the left side of your project page.

Remember, the contest isn’t just about winning a scope, a meter, or any of the other prizes. It’s about creating new Open Hardware designs that nearly anyone can build. So grab those soldering irons, load up those copies of the Arduino IDE, AVR-GCC, or WinAVR, and get hacking!

You can view the all of the contest entries in this list.

Hacklet 23 – The Groove Tube

The transistor may rule the electronics world today, but before solid state moved in, vacuum state was king. Tubes, or valves if you’re from Europe, were the only way to fly. Every good hacker knew their triodes from their tetrodes and their pentodes. While technology has moved on, some hackers keep the past alive with tube based projects. This week on the Hacklet, we’re featuring some of the best tube projects on Hackaday.io!

SAMSUNGWe start with [256byteram] and Tube Television Tennis. [256byteram] is building an entire Pong style game from tubes, including a CRT to display the game. Displaying anything on a standard television means generating lots of timing signals. [256byteram] is doing this by using multivibrators to create one-shots and flip-flop circuits. Tube Television Tennis is still a work in progress, but [256byteram] already can display a paddle and move it around the screen in both X and Y. This project has already blown our minds!

tamp1From [Marcel] comes this great Low Voltage All-Tube Amplifier, which we featured on the blog earlier this year. [Marcel] does tubes without the danger of high voltage by using the ECL82 tube at 40 volts. The ECL82 incorporates both a triode pentode in one package, making it something of an integrated circuit. Power is provided by transformer while a PY88 tube handles rectifier duties, making this truly an all tube amp. A few passive components complete the design. We can’t wait to fire one up and hear some class A goodness while basking in the warm glow only a tube can create.

obsoleteTimeNo tube article would be complete without some nixies, and [opeRaptor] is here to provide them with Obsolete Time, a nixie tube clock! Obsolete Time uses IN-12 Russian nixie tubes, and goes for a minimalist design. Under the hood it’s all modern tech though, including a Bluetooth radio which allows the clock to be set via an Android app.

hybridHeadphone2[Brandon Foltz] is also getting into a vacuum state of mind as he takes Adventures in Hybrid Headphone Amps. [Brandon] is mixing the best of the old and new worlds by using a 6247 tube as the input stage to an LM386 single chip amplifier. This hybrid is still a work in progress, as [Brandon] is trying to clean up the sound from his LM386.

Hackaday.io update!

private-messageDid you know that we’re constantly upgrading Hackaday.io? We listen to your input on the feedback project, and we’re always adding new features to the site. If you haven’t noticed, you can now send private messages to other users. We’re sure this will help put users in contact with each other, so they can collaborate on even more projects! On the left side of each profile page there is a “Send a private message” button below the hacker’s avatar. You now have better indicators when you have messages or updates too! The private messages and feed icons at the top right of every .io page now have indicators to show how many messages or feed entries you have waiting. These are all based on live data, so they’ll update as you browse the site.

That’s all the time we have for this week’s Hacklet! As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Push Button, Receive Bacon.

Members of the Rabbit Hole hackerspace spent the last weekend competing in The Deconstruction, a 48 hour hackathon competition. The hackerspace’s theme was “Light it up!”, so members created some awesome projects involving light. The star of the show was their bacon cooking machine. The Rabbit hole made the “Push Button. Receive Bacon” meme real.

A broken laser printer was gutted for its drive train and fuser assembly. Laser printer fusers are essentially hot rollers. The rollers melt toner and fuse it with paper as it passes through the printer. The heat in this case comes from a lamp inside the roller. That lamp also puts out plenty of light, which fit perfectly with the team’s theme.

The Rabbit Hole members wasn’t done though, they also built a pocket-sized infinity mirror from an empty Altoids tin. The bottom of the tin was cut out, and a mirror glued in. A filter from a broken projector made a perfect half silver mirror, and some LEDs completed the project.

The members also built a fandom art piece, consisting of 25 fans connected together in a skull shape. The eye and nose fans were lighted. When the fans were plugged in, they kicked for a few seconds before spinning up. Once they did spin though – there was a mighty wind in the Rabbit Hole.

Click past the break for The Rabbit Hole’s Deconstruction video!

Continue reading “Push Button, Receive Bacon.”

Extreme Repair of an All-in-One PC

While browsing a local auction site, [Viktor] found himself bidding on a beat up Lenovo A600 all-in-one PC. He bid around $50 and won. Then came the hard part – actually making the thing work. The front glass was cracked, but the LCD was thankfully unharmed. The heat pipes looked like they had been attacked with monkey wrenches. The superIO chip’s pins were mangled, and worst of all, the MXM video card was dead.

The first order of business was to fix the superIO chip’s pins and a few nearby discrete components which had been knocked off their pads. Once that was done, [Viktor] was actually able to get the computer to boot into Linux from a USB flash drive. The next step was bringing up the display. [Viktor] only needed a coding station, so in addition to being dead, the video accelerator on the MXM wasn’t very useful to him. The Lenovo’s motherboard was designed to support video on an MXM card or internal video. Switching over meant changing some driver settings and moving a few components, including a rather large LVDS connector for the display itself. A difficult task, compounded by the fact that [Viktor’s] soldering tools were a pair of soldering guns that would be better suited to fixing the bodywork on a ’57 Chevy. He was able to fashion a hot wire setup of sorts, and moved the connector over. When he was done, only one tiny solder bridge remained!

The end result is a new coding battle station for [Viktor] and a computer which was a basket case is saved from the landfill. If you like this hack, check out [Viktor’s] low power PSU, or his 1 wire network!

Play Music on a High Voltage Keyboard

[Matt] works at a neon sign power supply company. When a vendor error left him with quite a few defective high voltage transformers, he couldn’t bring himself to toss them in the bin. [Matt] was able to fix the transformers well enough to work, and the idea for a high voltage keyboard began to brew. Unfortunately, the original transformers were not up to the task of creating a musical arc. At that point the project had taken on a life of its own. Matt grabbed some higher power transformers and started building.

The keyboard has 25  keys, each connected to an individual high voltage circuit with its own spark gap. The HV circuit is based upon a IR2153D self-oscillating half-bridge driver. (PDF link). The 2153D is modulated by a good old-fashioned 555 timer chip. No micros in this design, folks! The output of the IR2153D switches a pair of N-channel MOSFETS which drive the flyback transformers.

[Matt] created 25 copies of his circuit and built them up on individual PCBs. He assembled everything on a wooden board shaped roughly like a grand piano. The final project looks great – though [Matt] admittedly has no musical ability, so we can’t hear AC/DC flying out of those spark gaps just yet.

If you do want to hear sparks playing music, check out the OneTesla project we saw at MakerFaire NY 2013.

Continue reading “Play Music on a High Voltage Keyboard”

Bricked Raspberry Pi Displays History

[eN0Rm’s] Raspberry Pis are much more than just another brick in the wall. He’s used the popular embedded Linux platform to build several small rear projection screens in a brick wall (Imgur link). Brick shaped metal enclosures were mortared into the wall of the building. Each rear projection screen is illuminated by a DLP projector which sits inside the metal enclosure. The Raspberry Pis sit on a shelf below all this.  The bricks are in a building in the Aker Brygge section of Oslo, Norway, and show historical facts and short videos about the local area.

[eN0Rm] could have used a PC for this task, the price for a low-end PC with a few graphics cards probably wouldn’t have been much more expensive than several Raspberry Pi’s with cases. However, this system has to just work, and a PC would represent a single point of failure. Even if one Raspberry Pi goes down, the others will continue running.

The current installation is rather messy, but it’s just a test setup.  [eN0Rm] has already been taken to task for the lack of cable management in his Reddit thread.  As [eNoRm] says – first get it working, then make it pretty.