The Cheapest Crystal Oven

July 5, 2014 by Brian Benchoff 33 Comments

The crystals you’ll find attached to microcontrollers or RTCs are usually accurate to 100 parts per million at most, but that still means if you’re using one of these crystals as a clock’s time base, you could lose or gain a second per day. For more accuracy without an atomic clock, a good solution is an oven controlled crystal oscillator – basically, a temperature controlled crystal. It’s not hard to build one, and as [Roman] demonstrates, can be built with a transistor and a few resistors.

The heating element for this OCXO are just a few resistors placed right on the can of a crystal. A thermistor senses the heat, and with more negative feedback than the Hackaday comments section, takes care of regulating the crystal’s temperature. A trimpot is used for calibrating the temperature, but once everything is working that can be replaced with a fixed resistor.

This deadbugged circuitry is then potted in five minute epoxy. That’s a bit unconventional as far as thermal management goes, but the results speak for themselves: [Roman] can get a clock with this circuit accurate to a few seconds per year.

HammerPong Game Takes Pong To New Heights

July 5, 2014 by Will Sweatman 13 Comments

large scoreboard with lots of flashy lights

[Jason] is back at it again with another new twist on the technically sophisticated and advanced game of Pong. Fashioned in a ‘Chuck E. Cheese’ style platform, the two players stand side by side each other with large foam hammers. A wack sends the 32 bit ARM powered dot skyward and then back down to the other player, where another wack will send the dot back whence it came. A brightly lit scoreboard keeps track of how many dots slip by.

[Jason] is a veteran of pong inspired games, but putting the HammerPong game together brought with it some new challenges. After being unable to squeeze a few MDF panels into his car, and fighting off flies, yard debris and pet dander that were trying to attach themselves to his freshly painted artwork, [Jason] managed to get his project completed.

The HammerPong is powered by an Arduino Due that controls six WS2812 LED strips and runs the background code. Various latches, shift registers and power transistors control the lights and scoreboard. Be sure to check out the linked project for more detail, and take a look at the video demonstration after the break.

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A GSM Base Station With Software Defined Radio

July 5, 2014 by Brian Benchoff 40 Comments

gsm If you’re wondering how to get a better signal on your cellphone, or just want to set up your own private cell network, this one is for you. It’s a GSM base station made with a BeagleBone Black and a not too expensive software defined radio board.

The key component of this build is obviously the software defined radio. [Julian] is using a USRP B200 radio for this project. It’s not cheap, but it is a very nice piece of hardware capable of doing just about anything with GNU Radio. This board is controlled by a BeagleBone Black, a pretty cheap solution that puts the total cost of the hardware somewhere around $750.

The software side of the build is mostly handled by OpenBTS, the open source project for the software part of a cell station. This controls the transceiver, makes calls and SMS, and all the backend stuff every other cell station does. OpenBTS also includes support for Asterisk, the software of choice for PBX and VoIP setups. Running this allows you to make calls and send texts with your SDR-equipped, Internet-enabled BeagleBone Black anywhere on the planet.

The Rabbit H1 Is A Stationary Mouse Replacement

July 4, 2014 by Rick Osgood 6 Comments

rabbit h1

[Dave] has some big plans to build himself a 1980’s style computer. Most of the time, large-scale projects can be made easier by breaking them down into their smaller components. [Dave] decided to start his project by designing and constructing a custom controller for his future computer. He calls it the Rabbit H1.

[Dave] was inspired by the HOTAS throttle control system, which is commonly used in aviation. The basic idea behind HOTAS is that the pilot has a bunch of controls built right into the throttle stick. This way, the pilot doesn’t ever have to remove his hand from the throttle. [Dave] took this basic concept and ran with it.

He first designed a simple controller shape in OpenSCAD and printed it out on his 3D printer. He tested it out in his hand and realized that it didn’t feel quite right. The second try was more narrow at the top, resulting in a triangular shape. [Dave] then found the most comfortable position for his fingers and marked the piece with a marker. Finally, he measured out all of the markings and transferred them into OpenSCAD to perfect his design.

[Dave] had some fun with OpenSCAD, designing various hinges and plywood inlays for all of the buttons. Lucky for [Dave], both the 3D printer software as well as the CNC router software accept STL files. This meant that he was able to design both parts together in one program and use the output for both machines.

With the physical controller out of the way, it was time to work on the electronics. [Dave] bought a couple of joysticks from Adafruit, as well as a couple of push buttons. One of the joysticks controls the mouse cursor. The other joystick controls scrolling vertically and horizontally, and includes a push button for left-click. The two buttons are used for middle and right-click. All of these inputs are read by a Teensy Arduino. The Teensy is compact and easily capable of emulating a USB mouse, which makes it perfect for this job.

[Dave] has published his designs on Thingiverse if you would like to try to build one of these yourself.

Move Over Humans And Things, Flowers Now On The ‘Net

July 4, 2014 by Rich Bremer 12 Comments

Tweeting Poppy Plants

The ‘Internet of Flowers’ is upon us thanks to an artist named [Adrian]. He has designed a project that not only monitors the growth of Poppy Flowers but also monitors the soil, air and surrounding activity.

The entire project is based on a Raspberry Pi mounted in a purpose-built enclosure made from laser cut birch plywood. The enclosure is mounted in a window of an adjacent building that has a view of the flower bed. An internally mounted camera was carefully aligned so its field of view was mostly of the plants and would limit taking photos of unknowing passersby. The camera takes a snap shot every 5 minutes, see the time lapse video below.

Tweeting Poppy Plants A box containing sensors is installed in the flower bed. The intent of this project was not to have the Raspberry Pi spit out hard factual data regarding soil moistness, temperature and ambient noise, but to instead take that data from the sensors and send out a story-like narrative that makes the communication feel more personal. To receive these comments from the poppies, you can follow them on Twitter: @tweetingpoppy.

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Smart Skateboard Box Adds Sound Effects To Your Tricks

July 4, 2014 by James Hobson 2 Comments

Here’s a rather interesting project aimed at making music — using skateboards. It’s called SkateHack, and it’s an open source project that mixes customized hardware, electronics and skating.

They’ve been at work on two different projects, both of which utilize piezoelectric sensors and contact microphones. The first, built in Sweden back in July 2012, is called the Augmented Ramp, which transforms a skateboard half-pipe into a musical instrument. The piezoelectric sensors and contact microphones convert vibrations from the ramp intro digital triggers which are then processed by software to create music. The result is a unique medley which changes with every trick.

The second project is called the Bauxite, which is made much the same, but designed to be easily built by anyone. It’s a skateboard trick box which also transforms grinding and tricks into cool sound effects and music. They call it a skateboard-powered-music-sampler — which in all reality, it is.

For more info check out the videos after the break.

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THP Entry: Embedded Hardware Security With The ChipWhisperer

July 4, 2014 by Brian Benchoff 13 Comments

There are thousands upon thousands of papers discussing various aspects of embedded hardware security, and dozens of books covering the same subject. The attacks discussed in the literature are very cool – things like side-channel power analysis and clock glitching used to extract keys from a system. The experimental setups in these papers are extraordinarily expensive – you can buy a new car for less. [coflynn] was disheartened with the price of these tools, and thought building his own would make for a great entry to The Hackaday Prize.

The hardware part of the ChipWhisperer includes a breakout board with an FPGA, ADC, and connectors for a lot of different probes, adapters, breakout boards, and a target board, With all these tools, it’s not unreasonable to say that [coflynn] could carry out a power analysis attack on a lot of embedded hardware.

Open source hardware is just one part of this entry. The biggest focus of this project is the open source software for analyzing whatever the probes and target boards record. With this software, anyone can monitor the power used when a chip runs a cryptographic function, or glitch a clock for some unintended functionality in a device. In keeping with the academic pedigree of all the literature on these attacks, there are a ton of tutorials for the ChipWhisperer for all those budding security researchers out there. Very cool stuff, and arguably one of the most technical entries to The Hackaday Prize.

Video below.

The project featured in this post is an entry in The Hackaday Prize. Build something awesome and win a trip to space or hundreds of other prizes.