JTAGulator Finds Debug Interfaces

October 2, 2013 by Adam Fabio 24 Comments

jtagulator

[Joe Grand] has come up with a tool which we think will be useful to anyone trying to hack a physical device: The JTAGulator. We touched on the JTAGulator briefly during our DEF CON coverage, but it really deserves a more in-depth feature. The JTAGulator is a way to discover On Chip Debug (OCD) interfaces on unfamiliar hardware.

Open any cell phone, router, or just about any moderately complex device today, and you’ll find test points. Quite often at least a few of these test points are the common JTAG / IEEE 1149.1 interface.

JTAG interfaces have 5 basic pins: TDI (Test Data In), TDO (Test Data Out), TCK (Test Clock), and TMS (Test Mode Select), /TRST (Test Reset) (optional).

If you’re looking at a PCB with many test points, which ones are the JTAG pins? Also which test points are which signals? Sometimes the PCB manufacturer will give clues on the silk screen. Other times you’re on your own. [Joe] designed the JTAGulator to help find these pins.

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Electrified Yard Equipment Hauls Grass

October 2, 2013 by Adam Fabio 45 Comments

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[AmpEater] spent the summer converting yard equipment from internal combustion to electric power. The conversions run from a relatively tame Wheel Horse, to an insane Cub Cadet. The Wheel Horse lost its Kohler engine in favor of a hydraulic pump motor from a crown forklift. 48 volt power is supplied by MK lead acid gel cells. An Alltrax 300 amp controller keeps this horse reigned in.

On his Reddit thread, [AmpEater] says he is especially proud of his Cub Cadet zero turn ride on mower. For those who aren’t up on lawn implement terminology, a “zero turn” means a mower with zero turning radius. Zero turn mowers use two large wheels and tank style steering to turn within their own radius. We bet this style mower would also make a pretty good robot conversion, however [AmpEater’s] zero turn is still setup for cutting the grass.

After pulling the V-twin motor the 48 volt Motenergy ME-1004 was put in place. Batteries are 3 x Enerdel 48V 33 amp hour lithium ion packs. The packs are wired in series to provide 144V nominal. Right about here is where our brain started to melt. A 48V motor on 144V has to mean magic smoke, right? This is where the motor controller magic comes in.

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Upgrading Cordless Drill Batteries To Lithium

September 29, 2013 by Marsh 27 Comments

Cordless power tool battery replacements are expensive: you can easily spend $100 for a NiCd pack. [henal] decided to skip nickle-based cells and cut out the middleman by converting his old cordless battery packs to inexpensive hobby lithium cells. These batteries appear to be Turnigy 3S 1300mAh’s from Hobbyking, which for around $10 is a great bargain. As we’ve explained before, lithium batteries offer several advantages over NiMH and NiCd cells, but such a high energy density has drawbacks that should be feared and respected, despite some dismissive commenters. Please educate yourself if you’ve never worked with lithium cells.

[henal] gutted his dead battery packs and then proceeded to prepare the lithium replacements by soldering them to the cordless pack’s power connectors. To keep charging simple, he also branched off a deans connector from power and ground. After cutting some holes in the pack for access to the balancing connector and deans connector, [helan] went the extra mile by soldering on a DIN connector to the balancing wires, which he then securely glued to the side of the case.

We’ve featured lithium power tool replacements before, and these Turnigy packs pose the same problem: they don’t appear to have any low voltage cut-off protection. Check out some of the comments for a good solution.

An Oscilloscope On Your Wrist

September 27, 2013 by Adam Fabio 36 Comments

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Calculator watches were the Geek cred of the 80’s. Today everyone is getting smart watches. How can the hip Geek stay ahead? [Gabriel Anzziani] to the rescue with his Oscilloscope Watch! [Gabriel] has made a cottage industry with his micro test tools. We’ve featured his Xprotolab and Xminilab on here on Hack a Day more than once. The Oscilloscope Watch basically takes all the features of the Xprotolab and squeezes them down into a wrist watch.

The Oscilloscope Watch includes an oscilloscope, a logic analyzer, an arbitrary waveform generator, and of course it tells time. The Oscilloscope Watch’s processor is the AVR XMega128. [Gabriel] has even included a link to the schematics (PDF) on his Kickstarter page. We really like that 3D printed case, and hope [Gabriel] opens up his CAD designs for us to work with.

Like its predecessors, the Oscilloscope watch won’t be replacing your Tektronix scope, or even your Rigol. Much like a Swiss army knife or Leatherman tool, the Oscilloscope Watch packs a bunch of tools into a small package. None of them are as good as a full-sized tool, but in a pinch they will get the job done. If you are wondering where the probes connect. [Gabriel] states on the Kickstarter page that he will design a custom 9 pin .100 connector to BNC adapter to allow the use of standard probes.

The screen is the same series of Sharp Memory LCD’s used in the Pebble watch. [Gabriel] chose to go with the FPC version of the Sharp LCD rather than the zebra connector. We’ve learned the hard way that those flex circuits snap at the LCD glass after only a few flexes. Hopefully this won’t impact the hackability of the watch.

An Improvised ATtiny2313 Logic Analyzer

September 27, 2013 by Brian Benchoff 13 Comments

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After banging his head against a wall trying to get a PS/2 interface to work, [Joonas] decided he needed a dedicated logic analyzer. He didn’t need anything fancy; writing bits to a serial port would do. He came up with a very, very simple ATtiny2313-based logic analyzer that can capture at 50+ kHz, more than enough for a PS/2 port.

The hardware for [Joonas’] build is a simple ATtiny2313 breadboard adapter, an FTDI Friend, and not much else. The 2313 has eight input ports on one side of the chip, making attaching the right logic line to the right port a cinch.

The highs and lows on each logic line are sent to a computer over the FTDI chip, converted into OLS format, and piped into Open Sniffer to make some fancy graphs.

[Joonas] was able to capture PS/2 signals with his logic sniffer, so we’ll call this project a success. However, there were a few problems that made this project a little more trouble than it was worth: there is no easy way to turn a serial dump into a binary file, Putty didn’t allow suppressing output to the terminal, and Mac serial ports twinkling above 115.2 kbps don’t work natively. Still, the project did its job, and we couldn’t ask for anything more.

[via Dangerous Prototypes]

World Maker Faire: We Annoy The DIWire Crew

September 24, 2013 by Brian Benchoff 7 Comments

diwire

Last year at Maker Faire we ran into the folks from Pensa Labs, the crew behind the very cool DIWire CNC wire bender. They were back again in full force this year with a new, improved, and soon-to-be commercially launched wire bender.

The first time we saw the DIWire it was a very cool piece of kit, but something that might not hold up to the rigours of a production environment. The latest version, a 14×8.5×5.5 inch machine designed to be set into a table, allowing for rapid manufacturing of nearly any shape imaginable bent into 1/8″ and 1/16″ steel wire.

Making any shape with the DIWire is extremely simple: if you have an SVG file, just import it into the software, define a few points along a path, and slip in a length of wire. One of the guys from Pensa was able to re-create the Hackaday logo is a few minutes.

It’s an impressive piece of kit that a few makers, hackers, and architects are using to build structures that can’t be made any other way. The DIWire will soon be released to the public, so check out their site for updates.

DIY High Stability Timebase Hack For ~$25. Why? Frequency Stability Matters!

September 23, 2013 by Todd Harrison 25 Comments

If you have an old “Racal-Dana 199x” frequency counter or similar 10 MHz internally referenced gear with a poor tolerance “standard quartz crystal oscillator” or bit better “temperature compensated crystal oscillator” (TCXO) you could upgrade to a high stability timebase “oven controlled crystal oscillator” (OCXO) for under $25. [Gerry Sweeney] shares his design and fabrication instructions for a DIY OCXO circuit he made for his Racal-Dana frequency counter. We have seen [Gerry] perform a similar upgrade to his HP 53151A, however, this circuit is more generic and can be lashed up on a small section of solderable perf board.

Oven controlled oscillators keep the crystal at a stable temperature which in turn improves frequency stability. Depending on where you’re starting, adding an OCXO could improve your frequency tolerance by 1 to 3 orders of magnitude. Sure, this isn’t as good as a rubidium frequency standard build like we have seen in the past, but as [Gerry] states it is nice to have a transportable standalone frequency counter that doesn’t have to be plugged into his rubidium frequency standard.

[Gerry’s] instructions, schematics and datasheets can be used to upgrade any lab gear which depends on a simple 10 MHz reference (crystal or TXCO). He purchased the OCXO off eBay for about $20 — it might be very old, yet we are assured they get more stable with age. Many OCXO’s require 5 V, 12 V or 24 V so your gear needs to accommodate the correct voltage and current load. To calibrate the OCXO you need a temperature stable variable voltage reference that can be adjusted from 1 to 4 volts. The MAX6198A he had on hand fit the bill at 5 ppm/°C temperature coefficient. Also of importance was to keep the voltage reference and trim pot just above the oven for added temperature stability as well as removing any heat transfer through the mounting screw.

You can watch the video and get more details after the break.

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