Category: Technical Articles

September 17, 2012 / / Electronics
August 28, 2012 / / Electronics
NI 9237 Bridge Module
NI 9237 Bridge Module

If you’re designing a data acquisition system with Wheatstone bridge-based sensors to be measured, the easiest (if not cheapest) solution comes from National Instruments in the form of the NI 9237 CompactDAQ module. Boston University’s Rocket Team (http://www.bu.edu/rocket) will be using this guy in upcoming tests this academic year to make sure our static motor data is as precise and repeatable as possible.

July 9, 2012 / / Electronics

I just recently got a good deal on a second-hand Hantek DSO1060 – not the greatest scope in the world at 60MHz bandwidth/2ch/150MS/s (note: sub-nyquist for two channel). However, for what I paid, it was a darn good deal, especially since I don’t have a true DSO with your standard math functions (my main scope is the Tek 2221a, which has both analog and digital modes, where digital has none of the niceties like FFT/multiply/divide).

Coincidentally, I also just found myself building from spare parts, then trying to troubleshoot, a computer that happened to sporadically restart itself with no obvious cause. After loading the bios, then noticing odd case fan behavior where it would spool up and down over and over, then noticing the BIOS reporting highly unstable voltages, I started suspecting the power supply. And out came the DSO1060!

Make EncFS work, fast.

For some reason, installing and running EncFS on Mac seems to be unnecessarily difficult. This is what I ended up with, and it should take you about 5 minutes to set up, start to finish if you’ve already got homebrew installed.

April 25, 2012 / / Coding
November 29, 2011 / / Electronics
Eagle parts!

I finally got around to putting my personal Eagle parts library on Github. There’s not much else to it, find it here here. The most noteworthy thing in there is the SOT223-5 footprint, which I couldn’t find anywhere online or in the default libraries. Enjoy! Complete listing below.

November 28, 2011 / / Electronics
USB IR Toy v3

I got the USB IR Toy v3 as a free PCB from Dangerous Prototypes a few weeks back, but until recently I haven’t had much time to track down all the parts for it. Given that this is a v3 and not a v2, there isn’t a simple shopping cart of parts at Mouser kicking around. So, I decided to make one!

November 28, 2011 / / Electronics
The new copper tape in place

I’ve been getting great use out of my modded Evil Mad Scientist Laboratories Bulbdial clock (you might remember, I modded it with a touch sensitive strip to turn the display on and off), but it’s been having some problems lately. Because I couldn’t solder to the aluminum tape I previously used, the contacts taped in place were getting loose, causing the clock to flicker on and off. The loose contacts also made functionality very sporadic. The solution was to swap the aluminum strips out with the copper foil I bought a while back from Sparkfun for a whopping $3. 

November 20, 2011 / / Coding
STM32F4-Discovery

ST Micro in the last few weeks was the first to market with the brand new ARM Cortex-M4 32-bit microcontroller core. The really interesting new feature is the ‘F’ in the name – this is the first low-cost, low-ish-power light duty microcontroller to include a built in, single cycle per instruction 32-bit floating point unit. In typical ST fashion, the development board is awesome – it’s got a built in ST-LINK/V2 programmer and in-circuit debugger on the top half. The bottom half contains the M4 and a host of fun peripherals to play with, including a 3-axis MEMS accelerometer, an audio DAC with class D output driver, a bunch of LEDs, and all GPIOs broken out to .1″ headers.

August 18, 2010 / / Electronics

This may seem tirade-ish, and if so I’m sorry. This was spurred by the story posted here at TUAW. Basically, there’s a little USB pass through dongle that you can buy to eliminate your iPad “not charging” woes. TUAW kind of misses the boat on bothering to explain or understand it, so here’s how it works, in comment-on-the-article form (so read the article first):