The Cranky Sysadmin

March 23, 2014

Edimax wifi with BeagleBoneBlack Angstrom 6.20 image

Filed under: Electronics,System Administration — Cranky Sysadmin @ 8:52 pm

This process was relatively straightforward for me, but it required looking at several sources. I don’t compile any kernels. I just found the appropriate firmware and loaded it on the bbb. I then did some hand waving and sacrificed a chicken and it all worked. Check below the fold for details.
edimax on bbb

October 26, 2013

Pano Logic Updates from the UK

Filed under: digital logic,Electronics — Cranky Sysadmin @ 10:07 am

A few weeks ago, I shipped one of my pano-logic clients to a fellow in the UK named Tim. These neat devices are hard to get over there. Tim’s intent is to do further work figuring out how to utilize the FPGA and parts on the G1 client. I’m posting his latest update as a copy-and-paste from his email. I’ve formatted the links.
Tim’s pano-logic updates

August 17, 2013

More Reverse Engineering of the Panologic Thin Client G1

Filed under: digital logic,Electronics,Pano Logic — Cranky Sysadmin @ 7:11 pm

I’ve been working on figuring out how to use my pano logic client as an FPGA dev board. Today I will detail the pin commections for the SPI flash, the Wolfson audio chip, and that partially identified Micron memory chip.
memory and audio details

August 10, 2013

More DSP Resources (and maybe a little math)

Filed under: Electronics,ham radio — Cranky Sysadmin @ 2:51 pm
  • A Visual Intuitive Guide to Imaginary Numbers. Imaginary numbers used to make my head hurt. If you’re shooting for your General or Extra class ham license, they will make your life easier. They’re also the basis for a lot of DSP work.
  • Quadrature Signals. Also explains complex numbers and then does a deep dive into quadrature signals which are used in a lot of aspects of DSP.
  • Bores Introduction to DSP. Somewhat math heavy with summations and integrals, but still an approachable introduction.
  • dsPIC tutorial and “Robotics 3.1“. Dig around on these blogs for basic information about how to use the dsPIC30 series PIC DSP processors. Most of the examples don’t seem to need the DSP portion of the chip, but it will get you started without going to basic PIC microcontrollers.
  • AE6TY. This ham does a great job of explaining his SDR implementation using DSPIC and some ADC’s. Don’t miss his Intro2SDR under the papers section. His DSPExplorer application looks nice too but I’ve only taken a cursory glance at it so far.

July 21, 2013

Exploiting the FPGA in the Pano Logic Zero Client

Filed under: digital logic,Electronics,Pano Logic — Cranky Sysadmin @ 8:58 pm

I’ve managed to find some useful I/O and program the FPGA on my new (to me) Pano Logic Zero Clients. Below are the steps you could take to start working on these cheap but large FPGAs. I assume that you are facile with Xilinx ISE and have a jtag cable which works with either impact or adept2.
cheap FPGAs Woohoo

July 20, 2013

In Search of FPGAs or Pano Logic Generation 1 Teardown

Filed under: digital logic,Electronics,Pano Logic — Cranky Sysadmin @ 7:44 pm

In my general search for fpga’s and devices I might use for SDR projects, I came across a hackaday article on the topic. The comments on the topic are promising, so I went ahead and started looking for a Pano Logic Zero Client. I didn’t just find one. I found ten for $50 on ebay! These are the generation 1 version. It turns out that this is probably a better choice for me anyway. The generation 2 has an enormous Spartan-6 LX150 which is nice, but ISE webpack isn’t licensed to program it. The gen 1 has a Spartan 3E XC3S1600E. This is still a large (by my standards) fpga and the webpack license will program it fine. See below the fold for a teardown and some details.
The Fold

July 13, 2013

DSP Resources

Filed under: Electronics,ham radio — Cranky Sysadmin @ 9:59 am

I’m learning DSP basically from the ground up without an advanced math background. My goal is to gain a deep understanding of digital signal processing (I’ll define deep when I’m tired of learning). Below are some of the resources that I’m using to get started. As I find more resources, I’ll add them here.

  1. Analog Devices DSP Primer. A very brief 10,000 foot overview.
  2. FFT for dummies. This page doesn’t actually get into the details of Fast Fourier Transform, but it does describe sampling methods and how to interpret the output of FFT programs.
  3. The DSP chapter in a recent ARRL Handbook. Chapter 15 in the 2013 edition. This has an overview and PIC based examples of the pieces of a software defined radio.
  4. Signal Processing for Communications. I have only started reading this free online resource. It is the textbook for the Coursera DSP course. It’s available for free Download.
  5. The Scientists’ and Engineers’ guide to Digital Signal Processing. I haven’t started reading this yet. It’s available for free download or hardcover purchase.
  6. Calculus Made Easy. I have a newer edition with more chapters. If I want a deep understanding of DSP, I am probably going to need to learn Calculus.
  7. Experimental Methods in RF Design chapters 10 and 11 (revised 1st edition). Looks like lots of practical stuff here. They use an ez-kit lite adsp-2181 which I’m having a hard time finding.

June 30, 2013

Don’t Disturb the Dust!

Filed under: Electronics,ham radio — Cranky Sysadmin @ 11:39 am

My Heathkit® project took a turn for the worse yesterday. There was some occasional arcing in the audio section when I turned on the radio. The cause seemed to be the sediment on the board. Do you know that feeling you get when you’re about to do something bad? Yeah, I’ve discussed this before, and I ignored that feeling again. Instead of taking the safe and lazy route of tracing down where the arcing was coming from, I decided now was a good time to lift the audio board out and clean it up. As the dear reader might predict, the audio section is now non-functional. I’m pretty sure things are wired up correctly. My current suspicion after triple-checking the wiring is that I disturbed some marginal component enough to stop it from working. I’ll have to look at after I complete some other easy projects that have been languishing, like my solar charging station and short vertical antenna.

June 25, 2013

The Tubes All Light Up. It Must Be A-OK

Filed under: Electronics,ham radio — Cranky Sysadmin @ 7:27 pm

After the great HW-100 conflagration of 2013, I figured I’d proceed with more caution in powering up the radio. I rewired the power cable, then looked over the HW-100. I replaced the electrolytic caps, and I found the source of the loud pop during my initial test. Fortunately, it was just what looked like solder dust on the audio board. I cleaned the boards up as good as I could without tearing it down. I then proceeded to power up with care. All of the tubes light up, and there is no smell of burning electronics. I plugged in a pair of head phones and tuned around. The radio appears to receive on all bands though it seems a little deaf on 20 meters. I am so glad I didn’t burn up anything obvious. Tomorrow, I will start the alignment process.

June 24, 2013

Hard Lessons About Old Heathkit® Gear

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

I recently purchased an old (possibly older than me) Heathkit® HW-100 transceiver and a HP-23 (the “first edition”). After getting it home, I immediately proceeded to plug it in and test it. You know that nagging feeling you get when you’re doing something you shouldn’t? Well, I ignored that. When I plugged in the supply, the fuse popped. I took a look inside. It was wired wrong in several ways. While I spent time rewiring it, I noticed that the electrolytic caps were light as a feather. I replaced those and tested the power supply with much better success. Don’t trust the ebay add that states “tested good”.

I then proceeded to plug in the 11 pin cable to the power supply and the HW-100. You know that nagging feeling you get when you’re doing something you shouldn’t? Well, I ignored it again. I powered up the radio. There was a loud pop in the radio and one of the audio tubes glowed white hot. By now you see the pattern of my misdeeds. It turns out that the cable is wired completely incorrectly for an HW-100. It almost looks like it’s mostly wired partially backward.

Well, once I fix the cable, I’m going to give the HW-100 a good going over. The ebay sale listed a litany of problems which looked fixable. Now it has at least one more problem. I hope I have the tubes and components to fix my mistake.

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