Teensy 3.1 Controlled VFO

March 5, 2016 by Rud Merriam 27 Comments

[Tom Hall], along with many hams around the world, have been hacking the Silicon Labs Si5351 to create VFOs (variable frequency oscillators) to control receivers and transmitters. You can see the results of his work in a video after the break.

[Tom] used a Teensy 3.1 Arduino compatible board, to control the Si5351 mounted on an Adafruit breakout board. An LCD display shows the current frequency and provides a simple interface display for changing the output. A dial encoder allows for direct adjustment of the frequency. The ham frequency band and the frequency increment for each encoder step are controlled by a joystick. When you get into the 10 meter band you definitely want to be able to jump by kHz increments, at least, since the band ranges from 28 MHz to 29.7 MHz.

So what is the Si5351? The data sheet calls it an I2C-Programmable Any-Frequency CMOS Clock Generator + VCXO. Phew! Let’s break that down a bit. The chip can be controlled from a microprocessor over an I2C bus. The purpose of the chip is to generate clock outputs from 8 kHz to 160 MHz. Not quite any frequency but a pretty good range. The VCXO means voltage controlled crystal oscillator. The crystal is 25 MHz and provides a very stable frequency source for the chip. In addition, the Si5351 will generate three separate clock outputs.

[Tom] walks through the code for his VFO and provides it via GitHub. An interesting project with a lot of the details explained for someone who wants to do their own hacks. His work is based on work done by others that we’ve published before, which is what hacking is all about.

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Rube Goldberg PC/Console Game Hack

January 28, 2016 by Elliot Williams 19 Comments

There’s no holy war holier than establishing whether PC games are superior to console games (they are). But even so, there’s no denying that there are some good console titles out there. What if you’d still like to play them using a mouse and keyboard? If you’re [Agent86], you’d build up the most ridiculous chain of fun electronics to get the job done.

Now there is an overpriced off-the-shelf solution for this problem, and a pre-existing open-source project that’ll get the same job done for only a few bucks in parts. But there’s nothing like the fun in solving a problem your own way, with your own tangle of wires, darn it all! The details of the build span four (4!) pages in [Agent86]’s blog, so settle down with a warm cup of coffee.

Here’s the summary: an Xbox 360 controller is taken apart and turned into an Xbox controller. The buttons and joysticks are put under computer control via a Teensy microcontroller. GPIOs press the controller’s buttons, and digipots replace the analog sticks. Software on the Teensy drives the digipots and presses the buttons, interpreting a custom protocol sent over USB from the computer, which also gets some custom software to send the signals.

So if you’re keeping score: a button press on a keyboard is converted to USB, sent to a PC, converted to a custom serial protocol, sent to a Teensy which emulates a human for a controller that then coverts the signals back into the Xbox’s USB protocol. Pshwew!

Along the way, there’s learning at every stage, which is really the point of an exercise like this. And [Agent86] says that it mostly works, with some glitches in the mouse-to-joystick mapping. But if you’re interested in any part of this crazy chain, you’ve now got a model for each of them.

RGB LED Ceiling Display

December 20, 2015 by Anool Mahidharia 8 Comments

Disco Floor’s are passé. [dennis1a4] turned them upside down and built an awesome RGB LED ceiling display using some simple hardware and a lot of elbow grease. His main room ceiling was exactly 32 ft x 20 ft and using 2 sq. ft tiles, he figured he could make a nice grid using 160 WS2812B RGB LEDs. A Teensy mounted in the ceiling does all the heavy lifting, with two serial Bluetooth modules connected to it. These get connected to two Bluetooth enabled NES game controllers. Each of the NES controller is stuffed with an Arduino Pro Mini, a Bluetooth module, Li-Ion battery and a USB charge controller.

Bluetooth is in non-secure mode, allowing him to connect to the Teensy, and control the LEDs, from other devices besides the NES controllers. The Teensy is mounted at the centre of the ceiling to ensure a good Bluetooth link. Programming required a lot of thought and time but he did manage to include animations as well as popular games such as Snake and Tetris.

The hard part was wiring up all of the 160 LED pixels. Instead of mounting the 5050 SMD LED’s on PCBs, [dennis1a4] wired them all up “dead bug” style. Each pixel has one LED, a 100nF decoupling capacitor, and 91 ohm resistors in series with the Data In and Data Out pins – these apparently help prevent ‘ringing’ on the data bus. Check the video for his radical soldering method. Each SMD LED was clamped in a machine shop vice, and the other three parts with their leads preformed were soldered directly to the LED pins.

The other tedious task was planning and laying out the wiring harness. Sets of 10 LEDs were first wired up on the shop bench. He then tacked them up to the ceiling and soldered them to the 14 gauge main harness. The final part was to put up the suspended ceiling and close the 2 sq. ft. grids with opaque plastic.

[dennis1a4] did some trials to figure out the right distance between each LED and the panel to make sure they were illuminated fully without a lot of light bleeding in to adjacent panels. This allowed him to get away without using baffles between the tiles.

Check out the video to see a cool time-lapse of the whole build.

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Small-farm Automation Keeps Livestock Safe And Happy

December 15, 2015 by Dan Maloney 15 Comments

Life down on the farm isn’t easy, and a little technology can go a long way to making things easier for the farmer. It’ll be a while before any farmer can kick back on the beach and run his place from a smartphone, but that’s clearly the direction things are heading with this small farm automation project.

[Vince]’s livestock appears to consist of chickens and sheep at this point, and the fact that they share housing helped him to deploy some tech for both species. The chickens got an automated door that lets them out in the morning and shuts them in safely once they’ve returned to roost for the night – important protection against predators. The door is hoisted by a Somfy window-treatment motor, which seems a little on the overkill side to us; a thrift-store electric drill and a homebrew drum might have worked too. A Teensy with an RTC opens and closes the door according to sunrise and sunset times, and temperature and humidity sensors provide feedback on conditions inside the coop. The sheep benefit from a PTZ webcam to keep an eye on their mischief, and the whole thing is controlled by a custom web interface from [Vince]’s smartphone.

There’s just something about automating chicken coop doors that seems to inspire hackers; check out this nice self-locking design. As for [Vince]’s farm, it looks like his system has a lot of room for expansion – food and water status would be a great next step. We’re looking forward to seeing where he goes from here.

The Best Badges Of The SuperCon

December 9, 2015 by Brian Benchoff 5 Comments

A few weeks ago, we took a look at the best badge hacks at the Hackaday Supercon. These were the best badge hacks anyone has ever seen – including what comes out of DEF CON and the SDR badge from the latest CCC. I’m ascribing this entirely to the free-form nature of the badge; give people a blank canvas and you’re sure to get a diverse field of builds. Now it’s time to take a look at the cream of the crop, hear what the jolly wrencher sounds like, and how to put 1000 Volts in a badge.

There were three categories for the badge hacking competition at the SuperCon – best deadbug, best blinky, and most over the top. A surprising number of people managed to solder, glue, and tape some components to a the piece of FR4 we used as a conference badge, but in the end, only three would win.

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A Teensy Logic Analyzer For A 6502

December 4, 2015 by Brian Benchoff 11 Comments

[John] has an interesting, if old piece of tech sitting on his workbench. It’s an Ohio Scientific C3-8P computer from the late 70s by way of a few garages, basements, and attics. As with most tech of this vintage, there are some problems, and [John] found debugging a little frustrating without the ability to trace and watch the programs. He needed a logic analyzer, and found one in an unlikely piece of hardware. [John] built one using a Teensy microcontroller, and further refinement of this project could turn it into a full in-system emulator.

The old Ohio Scientific computer [John] is trying to bring back from the dead is based on the 6502 CPU. That’s sixteen address lines to monitor, eight data lines, and four control lines. These were wired directly to a Teensy 3.1.

Reading and controlling all the signals from a 6502 is a task that falls to Linux. A command line program controls the Teensy and is capable of reading memory, setting trigger addresses, dumping the entire address space to a file, or just recording the last 5,000 clock cycles. This kind of tech existed back in the late 70s and early 80s. It also cost a fortune. Now, with a $20 Teensy and probably another $30 in ribbon cables and test clips, anyone can build a logic analyser for a very old computer system.

Videos below.

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Turning A Teensy Into A Better U2F Key

November 14, 2015 by Brian Benchoff 11 Comments

A few days ago, we saw a project that used a Teensy to build a Universal 2nd Factor (U2F) key. While this project was just an experiment in how to implement U2F on any ‘ol microcontroller, and the creator admitted it wasn’t very secure, the comments for that post said otherwise: “making your own thing is the ONLY way to be secure,” read the comments.

In a stunning turn of events, writing comments on a blog post doesn’t mean you know what you’re talking about. It turns out, to perform a security analysis of a system, you need to look at the code. Shocking, yes, but [makomk] took a good, hard look at the code and found it was horribly broken.

The critical error of the Teensy U2F key crypto is simply how U2F is performed. During authentication, the device sends the U2F key handle to whatever service is trying to authenticating it. Because the key in the Teensy implementation is only ‘encrypted’ with XOR, it only takes 256 signing requests to recover the private key.

The original experimentation with using the Teensy as a U2F key was an educational endeavor, and it was never meant to be used by anyone. The attack on this small lesson in security is interesting, though, and [makomk] wrote a proof of concept that demonstrates his attack. This could be used to perform attacks from a remote server, but hopefully that won’t happen, because the original code should never be used in the wild.