Tag Archives: Arduino-Raspberry Pi

Project Night 2018

Every January Meeting we hold Project Night, where members bring in and share recent homebrew projects that they have built. This year’s Project Night was full of interesting projects built by our members.

Member Projects
Scott NE1RD Kits
Scott NE1RD Kits

Our Programs Chairperson, Scott, NE1RD led it off by showing us some kits he had built, including the K1EL PaddleStick Keyer that we will be building for the February Tech Night.

Bob KB1TEK - QRP Kits
Bob KB1TEK – QRP Kits

Bob, KB1TEK brought some QRP kits that he had built.

Dave K1DHP - VLF Detector
Dave K1DHP – VLF Detector

Dave, K1DHP showed us the VLF Detector that he built.

Hamilton, K1HMS – Antenna Switches

Hamilton, K1HMS brought Antenna Switches that he had built.

Dave K1DLM - Heakthkit
Dave K1DLM – Heakthkit

Dave, K1DLM showed us a Heathkit that he plans to build.

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Dennis, K1LGQ had another explosive presentation when he showed us a KX2 stand that he built.

Dennis shows plans for his KX2 Stand
Dennis hows plans for his KX2 Stand

 

Fred AB1OC - Low-Band Match
Fred AB1OC – Low-Band Match

Fred, AB1OC brought an 80m band matching system that he will install in order to make our 80m delta loop be resonant across the band.  He has programmed our MicroHam system to automatically have the box switch the matching system as we tune through the 80m band.  I’m looking forward to using this to get the last 20 80m contacts for my 5 Band DXCC!

Anita AB1QB - CW Pi
Anita AB1QB – CW Pi

I (AB1QB) demonstrated a Raspberry Pi project that I built over the holidays.  It is called a Morse Code Virtual Radio.  When you hook up a monitor and a straight key to the Raspberry Pi, it will decode what you key in.  This was a big hit with the kids who visited us for ARRL Kids Day.

Mike, AB1YK - Panadapter
Mike, AB1YK – Panadapter

Finally, Mike, AB1YK brought in a number of projects that he has done including a Panadapter and a CW Generator.

Anita AB1QB - CW PiScott NE1RD KitsMike AB1YK - PanadapterMike AB1YK - CW GeneratorHamilton K1HMS - Ant Switches 2Hamilton K1HMS - Ant Switches 1Fred AB1OC - Low-Band MatchFred Ab1OC - Low-Band Match 1Dennis K1LGQ - KX2 Stand 2Dennis K1LGQ - KX2 Stand 1Dave K1DLM - Heakthkit 2Dave K1DLM - Heakthkit 1Dave K1DHP - VLF DetectorBob KB1TEK - QRP Kits 2Bob KB1TEK - QRP Kits 1

Overall it was great to see all of the projects that our members have been working on. The gallery above contains more pictures from Project Night.

Anita, AB1QB

2018 Tech Night Survey Results

The results are in for the Tech Night program survey. We had 18 respondents and several volunteers to help with presentations.

In order to produce a meaningful ranking, a weight was given to votes for High, Medium, and Low. High was assigned a value of 10. Medium was assigned a value of 3. Low was assigned a value of zero. The score for each idea was then tallied, and the table sorted by score. Anything with a score below 95 was considered uninteresting at this time. Note that future surveys may have these very same ideas, and new members (or even old members) may rate the ideas higher later. Just because an idea didn’t get scheduled this year doesn’t mean it is off the table for next year.

I’m happy to say that five of the ideas that ranked highest have already been scheduled. We are also doing an Antenna Modeling program two nights, and a two-night kit build event in January and February to round out the package. As for the other popular ideas, we’ll be seeking out presenters for these in the coming weeks and months.

Here is a list of the ideas that made the cut:

Here are the remaining issues ranked, and a few more that were suggested during the survey.

Our hope is to bring interesting speakers and ideas to Tech Night. If you have ideas for program topics, or if you’d like to present at a Tech Night, please contact me.

Scott, NE1RD

Homebrew an Antenna Analyzer

If you’re like me, then you try to be judicious with your $$$. Ideally, it would be great to spend $ and get the highest quality in return. But, the world does not work this way. So, if I am going to spend $$$ (on a scale of $, $$, and $$$), I want to make sure not only am I obtaining quality, but also multi-functionality. In other words, it’s easier for me to spend more money when I feel like my purchase is not exactly a swiss-army knife but also not a one-trick pony.

I could be wrong, but antenna analyzers kind of feel like a one-trick pony to me. When I first strung up my Buckmaster 7-band OCF dipole, I borrowed the RigExpert AA-30 from Greg W1TEN, in order to measure the VSWR,  since I wasn’t thrilled about spending $200 for the analyzer. Especially because I would rather put that money towards a Heil headset and foot pedal (to be ordered for Xmas 2017).

At the October Board of Directors (BoD) meeting, Fred AB1OC mentioned that in the Nov 2017 issue of QST, there was an article entitled “Build Your Own Arduino-Based Antenna Analyzer” by Jack Purdum W8EEE and Farrukh Zia K2ZIA. The attractive thing about this design is the authors quote a price point of $50. The major components are comprised of an Arduino, AD9850 Direct-Digital Synthesizer (DDS) board, and TFT display. Additionally, on the main website, one can also download the associated software to load on the Arduino. So, this leaves the user with the experience and satisfaction of homebrewing a really useful component for the shack. There seems to be a lot of documentation on the assembly, parts, etc. so this makes it relatively easy for the user.

Homebrew Antenna Analyzer
Completed assembly of analyzer
Homebrew Antenna Analyzer
View of Arduino, PCB, and components for analyzer

A downside is that the number of components required seems to be somewhat large as seen from Farrukh’s website which could potentially be overwhelming if you are just beginning. The authors also quote that one helpful component is purchasing their own custom PCB for the job itself. Though this is not essential, it may aid in the build.

Having not built this yet, I would say this would be an intriguing build for someone. I would certainly like to tackle it and have added it near the top of my to-do list since it seems like it can be accomplished within a weekend.

A Cheaper Alternative?

After I read the article, I emailed Mike AB1YK to let him know about it. He replied with yet another option in the form of a PDF by K6BEZ who claims to accomplish the same feat in < $50. Definitely attractive! It’s built on the same premise: AD9850 DDS board, Arduino, etc., but seems to use fewer components. Instructions also seem to be located here. 

Some pitfalls of the build from the PDF link provided above:

  • I located some Yahoo forums discussing that the analyzer as spec’d out did not seem to work for some builders. It’s unclear if the schematics were incomplete or if it’s due to another reason entirely.
  • The build does not seem to be that much cheaper. For instance, the PDF lists the AD9850 DDS as being $4 on eBay. Having looked there myself, as well as on Amazon, the going rate seems to be in the neighborhood of $18-$19. Given this, along with looking up some of the other items in the bill of materials, the price point seems to approach $50 pretty quickly.

If I endeavor upon this, I will be sure to document and write another article about it. If someone attempts the “cheaper option”, I would be interested to hear how well it works.

Happy building!

Brian AB1ZO

DX Alarm Clock Part 2 – Hardware

I recently wrote a blog article about the DX Alarm Clock software – here is Part 2 of the Series on the how I built the hardware for the DX Alarm Clock.

DX Alarm Clock Hardware Components

The DX Alarm Clock is based on a Raspberry Pi 3 computer and an Adafruit Pi-TFT Touch Screen Display.  The list of components, along with links is below.  Since I built the Raspberry Pi almost a year ago and technology is always advancing, some of the parts are no longer available or have better replacements available.  I’ll provide information on what I used and a recommended replacement.  Approximate prices are included.

Raspberry Pi 3
Raspberry Pi 3

Motherboard: Raspberry Pi 3 ($35) – includes a 1.2 GHz 64-bit quad-core ARM CPU, Build in WiFi, Ethernet, 4 USB Ports, an HDMI port and audio port (3.5″) and Bluetooth.

Also, you will need a power adapter  ($10) and Class 10 Micro SD card ($15) for the Raspberry Pi.  Ours is a SanDisk Ultra 64GB Micro SD Card.

Pi-TFT Touch Screen Display
Pi-TFT Touch Screen Display

Display: Adafruit Pi-TFT 2.8″ Display with Capacitive Touch Screen ($45).  A slightly larger, 3.5″ display is now available.

PiBow Case
PiBow Case

Case: Pimoroni PiBow Case for Raspberry Pi and Pi-TFT Display($20)

Kinivo Speaker
Kinivo Speaker

Portable Speaker:  Any small portable/rechargeable speaker will do.  Mine is a Kinivo, but it is no longer available.  Any small speaker will do as long as it is Bluetooth or has a 3.5″ stereo connector.

Completed DX Alarm Clock Hardware
Completed DX Alarm Clock Hardware

The picture above shows the completed DX Alarm Clock Hardware running portable using a USB battery pack.

Raspberry Pi Development Environment

Raspberry Pi Development Environment
Raspberry Pi Development Environment

After constructing the Raspberry Pi, case and TFT Display, the next step was to connect it to a monitor via the HDMI port, a mouse via one of the USB ports and to a Bluetooth keyboard.   Then I loaded the Raspbian Operating System onto the Raspberry Pi via the micro SD card.  I first copied the OS to the Micro SD card using a PC or Mac and then inserted the card into the Raspberry Pi and booted from it.  You can find a good tutorial on how to do this at https://www.raspberrypi.org/learning/software-guide/quickstart/

Once Raspbian is installed, you will have a windows like GUI (Graphical User Interface) environment with a web browser, and a number of additional applications included.

This gave me a development environment that I could use to build and test the DX Alarm Clock software.  I used the Python language to develop the software.  I used the Python IDLE development environment, which is included in the Raspbian OS.

Interested in Raspberry Pi Amateur Radio Projects?  See the article on a Raspberry Pi Satellite Rotator Interface.