The Cranky Sysadmin A world of technology, fun, and ignorant rants.

June 12, 2013

Arduino Capacitive Touch Iambic Key (using attiny85)

Filed under: Arduino,Electronics,ham radio — Cranky Sysadmin @ 9:19 pm

Since I’m trying to learn morse code, I decided I’d build a key which functions as a trainer and an actual key. I’ve always liked the idea of capacitive touch sensors, so I went with that. This is a small project using a handful of parts. One should be able to finish it in an evening of focused work. Read on if you’re interested in the details.
Iambic key details

March 10, 2013

Arduino DDS Signal Generator Details

Filed under: Arduino,Electronics,ham radio — Cranky Sysadmin @ 7:44 pm

Past the fold are details on my rendition of an ardiuno DDS based signal generator. Included are the code, some schematics (not a full schematic though), and some hints on setting it up.
Signal Generator Details

February 26, 2013

Arduino Signal Generator Demonstration

Filed under: Arduino,Electronics,ham radio — Cranky Sysadmin @ 8:26 pm

I have a lot of work to do on my arduino DDS signal generator, but it’s good enough to demo. Too bad I’m bad on camera. Once I have this signal generator to the useful stage, I’ll post some details about it.

February 25, 2013

Antenna Analyzer Progress 1

Filed under: Arduino,Electronics,ham radio — Cranky Sysadmin @ 8:21 pm

I spent a fair portion of the weekend testing my new AD9850 DDS modules and attempting to use some bare AVR chips with internal oscillator as cheap arduino. Read past the fold if you’re interested in the progress.
The Fold

February 23, 2013

Two DDS Modules Have Arrived!

Filed under: Arduino,Electronics — Cranky Sysadmin @ 7:57 pm

I ordered two new AD9850 DDS modules from Amazon. They were shipped from China and arrived in about two weeks. For a quick test, I followed the instructions from N8RO. Both modules seem to work. According to my ancient but still seemingly accurate Fluke frequency counter, one module was off by about 100 hz at 10MHz, and the other was off by about 208hz. Each module will output a nice sine wave up to 40 mhz. Above that, the signal gets really small, and the wave form gets wonky looking. Since antenna analyzers need a signal generator, my next step is to breadboard out one with a DDS module, a rotary encoder, an LCD, and some push button switches.

February 18, 2013

HP HEDS-7501 encoder data

Filed under: Arduino,Electronics — Cranky Sysadmin @ 4:44 pm

I recently tore down some old controller for an X-ray device that I bought at a surplus shop for $15. I couldn’t find a data sheet for this model, so I derived the pinout from the circuit it was in. The pinout and characteristics that I could figure out follow the fold.
the fold

November 11, 2011

Some Starter Electronics Projects

Filed under: Arduino,Electronics — Cranky Sysadmin @ 6:03 pm

I’ve been having a lot of fun putting together my electronics lab and building some projects. I’m re-learning how to read schematics, and how to troubleshoot circuits. Even though I spent my time in the Marine Corps in a bit of a drunken haze, I’m recalling a lot of the basics quickly. Turn the page to see some of my most recent projects.
My starter projects

September 16, 2011

A New Old Hobby

Filed under: Arduino,Electronics — Cranky Sysadmin @ 8:48 am

When I was a kid, my dad would bring home various bits of electronics hardware he acquired from his job as a field engineer. I used to spend a lot of time desoldering components and building simple projects. When I joined the Marine Corps, I repaired RADAR, so I still got to play with a lot of hardware. I also got to learn how to use oscilloscopes, spectrum analyzers, and logic analyzers and other nifty pieces of test equipment. Since then, I’ve been losing touch with my hardware side as I became a sysadmin and a bit of a programmer.
An expensive hobby

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