Ham Radio

Computers and D-STAR and Ham Radio28 Jul 2017 07:27 pm

This issue came up at work this week.

I received two phone calls from customers who were having issues with their Raspberry Pi-based D-STAR Hotspot: something was corrupting the microSD card.

One wanted to get the built-in halt/reboot options working, and he eventually did with the help of the image’s site.

The second brought his RPi and laptop in for me to check on, and luckily he was using the same image as me, D-STAR Commander. After I set a new microSD card up for him, I popped it into my laptop, which runs Arch Linux, to do some modifications to /etc/fstab to allow for essentially hot unplugging of power. It involves RAM disks.

The procedure is quite easy and can be done before the RPi is booted up if you have an SD-card reader-equipped Linux machine.

If you’re already booted up on the RPi, connect to it via VNC (or SSH), open the Terminal, and follow the following steps:

1. Type “sudo nano /etc/fstab” and hit Enter.
2. Add the following lines to the file:

tmpfs /tmp tmpfs defaults,noatime,nosuid,size=100m 0 0
tmpfs /var/tmp tmpfs defaults,noatime,nosuid,size=30m 0 0
tmpfs /var/log tmpfs defaults,noatime,nosuid,mode=0755,size=100m 0 0
tmpfs /var/spool/mqueue tmpfs defaults,noatime,nosuid,mode=0700,gid=12,size=30m 0 0

(the last two lines are really one line. you can copy and paste if you need to)

3. Hit Ctrl-X and hit “Y” when prompted to exit and save the file.

Now reboot the RPi if it is running or unmount the microSD card and insert it into the RPi.

What this has done is create three RAM disks: one 30 MB in size, one 100 MB in size, and another 30 MB in size. The directories listed there often are continually written to, which can be catastrophic if power is removed while the microSD card is being written to. If they are in RAM, they disappear once the power is removed.

This solves the corruption issue with the D-STAR images.

Computers and D-STAR and Ham Radio24 Apr 2016 09:08 pm

Hi there! This is a landmark first post in almost four years here on w4jdh.net!

Today we’re diving into the realm of amateur (ham) radio and Linux, specifically how to set Arch Linux up as both an APRS I-Gate and a dual-band D-STAR hotspot using the G4KLX software compiled from source.

Assuming you don’t have Arch installed, take a look at their spectacular Beginners’ Guide. Once you have the machine set up, head back over here.

You will need to add a non-root user to complete this task. Once that’s done, it’s time to do some fun things.

In order to add software you have to be logged in as root, so use that to get the framework built up by inputting the following command on one single line:

# pacman -S git tigervnc sudo openssh wxgtk portaudio libusb webkitgtk webkitgtk2

After this use visudo to add your user to the sudo permissions by adding a line similar to the following:

<user> ALL=(ALL) ALL

which will require password entry to execute the command. If you wish for passwordless sudo change the final “ALL” to “NOPASSWD:ALL”. Once this is complete, log out from root and log into the user account.

The first order of business is to get XASTIR installed for APRS. Issue the following commands to prepare the environment:

git clone https://aur.archlinux.org/libax25/
git clone https://aur.archlinux.org/xastir/
git clone https://github.com/dl5di/OpenDV/

I added the OpenDV github repository to the end there to prepare for the next step.

To complete the installation of XASTIR, type cd libax25 then type makepkg -sri to install the AX.25 library, which is a dependency of XASTIR. After that, type cd ../xastir to enter XASTIR’s folder. Repeat makepkg -sri to install XASTIR.

Now it’s time for D-STAR. If you are still in the “xastir” directory, type cd ../OpenDV/ to enter the OpenDV repository clone. The first piece of this software suite you should install is ircDDBGateway, so type cd ircDDBGateway and follow it up with ./configure && make and sudo make install once it’s finished building. After installation, type cd ../DStarRepeater and repeat ./configure && make and sudo make install.

The OpenDV suite does something a bit odd now with log files and configuration. Both are put with a prefix of /usr/local, so it is necessary to create folders and change ownership. Use sudo su - to become root and execute the following commands:

mkdir /usr/local/etc/opendv
chown <user>:<user> /usr/local/etc/opendv
mkdir /usr/local/var
mkdir /usr/local/var/log
mkdir /usr/local/var/log/opendv
chown <user>:<user> /usr/local/var/log/opendv

This will set appropriate permissions for the installed software. Why the team did this change I have no idea.

With this, it’s time to select a window manager or desktop environment. I personally like the tiling window manager i3, though there are many many choices. A second choice would be LXDE. Both are available in Arch’s repository. I won’t cover installation of these as this is personal preference and covered quite well by the ArchWiki.

My personal recommendation for a relatively inexperienced user is to use LXDE as it resembles Windows in many ways. Use the “Run” command to start ircddbgatewayconfig to configure ircDDBGateway and dstarrepeaterconfig to configure DStarRepeater. If you have more than one DVAP or GMSK Board, you can use the configuration as dstarrepeaterconfig B for example.

Now the base system for D-STAR is built, and you can launch the software. Run ircddbgateway and dstarrepeater however many times you need to, and enjoy D-STAR!

Moving right along to XASTIR. It is far simpler: simply launch xastir from “Run” and configure it. It is reasonably straightforward.

That is it! While it’s not as “easy” as getting a Raspberry Pi image for D-STAR or installing XASTIR from Ubuntu’s repositories, it is very much more fun in my opinion. For one thing, the system is not nearly as heavily laden with “unnecessary” packages, so it needs far less memory to run. Secondly, as it is built from the most recent sources, it will usually have more features than a premade image. Finally, as it’s not a premade image, it will have a (hopefully) unique login and password for the account running the software. This is especially vital if used on any sort of public network, cellular included.

Conventions and Hamfests11 May 2010 05:44 pm

Here’s a scenario: you’ve found a {convention|hamfest|trade show|conference} you want to attend, have a hotel picked out, and have your method of transportation picked out. What you don’t know, though, is if you want to leave out Sunday evening or Monday morning. This was the scenario I ended up with in 2005 when it was decided that my group was going to get a room for Anime Weekend Atlanta.

I made reservations at the Renaissance Waverly earlier in the year and decided to go from Thursday to Sunday in my naïveté. As we rushed to exit the room Sunday morning, I decided that next year I would reserve from Thursday to Monday. I think that the tremendous crowd at the front desk Sunday morning was enough to dissuade me from booking for Sunday departure the next year. Furthermore, the rush to exit conspace to take a friend to the airport to catch his flight home wasn’t fun either.

I do a small amount of travel for my job, attending hamfests throughout the Southeast. In every case, we’re checking out of the hotel early Sunday morning to work the day and go home. This is to streamline the “putting the store back together” process.

In 2008, I went to three out-of-down conventions: Anime Boston, A-Kon, and Otakon. In each of these, I chose to fly home on Sunday. At AB and Otakon, I had access to public transit, so getting home wasn’t too big of a deal. At A-Kon, I had to rely on a longtime friend of mine to get me around. Fortunately, we decided after checking out that the con wasn’t worth staying at, so we dropped his wife off at their house then went and hung out for a bit before I departed.

All in all, I’ve determined over the past few years that whenever it’s feasible financially to stay over an extra day. I especially see this at AWA as I get to hang out with both my out-of-town friends and local friends at the same time. This leads to much random awesome that usually ends up with us being up half the night. Therefore, waking up at 8 or 9 on Sunday only to rush like madmen to get out of the hotel is usually deemed a bad idea.

As September rapidly approaches and this year’s plans for AWA continue to be set in motion, I prepare myself mentally, physically, financially, and emotionally for that weekend. I will definitely relish checking out on Monday instead of Sunday this year yet again.

Cellular and Conventions and Embedded and Hamfests and Networking24 Apr 2010 12:16 pm

Earlier this week, I read on TmoNews.com that T-Mobile was making another promo on their webConnect (aircard) service. I had cashed in on a promo plan towards the end of last year for $50/mo instead of $60/mo, but this one is even more awesome: “Overage Free” rate plan for $40/mo. What this means is that while the (now) soft cap of 5GB exists, past that they may throttle you down to EDGE speeds. I can live with that, and the fact that it isn’t a guaranteed throttle makes it even better.

What does this mean for the net-in-a-box project? It means EPIC AWESOME. I no longer have to worry too much about whether or not it goes over 5GB, and even if we go over 5GB at a con, I’m certain that EDGE speeds are still faster than a hotel connection shared with a full hotel. That’s assuming they enforce it heavily.

Needless to say, I phoned up 611 yesterday morning and got the plan switched over. I definitely await the forthcoming summer activities with this semi-unlimited data plan!

Ham Radio01 Feb 2006 03:26 pm

It’s fairly common knowledge that I possess an amateur radio license, callsign W4JDH. As such, I have this innate interest in things radio, and thanks to my overwhelmingly powerful interest in computers… I like things like packet radio and something called APRS, or the Automatic Position Reporting System, developed by Bob Bruninga, WB4APR. APRS itself isn’t all that interesting, but when you put it into actual practice, be it at a public service event like a parade or marathon, a weather station, or merely just plotting the position of mobile trackers on a map, it becomes an “ooh neat!” thing. It’s a cool way to have a visual demonstration of what amateur radio can do.

The most common use for it are mobile tracker stations in vehicles. This is corroborated by the nearly constant traffic on 144.39MHz (national APRS frequency) around most metro areas. Kenwood developed two radios thatthat are plug-and-play solutions for APRS, the TH-D7A and the TM-D700A. Both have ports on them to plug a GPS’s serial line directly into (by way of 2.5mm stereo jack) for appending position information to the APRS packet. I personally own both of these radios, so I’ve got a little bit of experience with them. I’ve never actually “fully” installed the D700 in my car yet (i.e. with GPS connected for real time plotting of my position) due to being lazy and also just not making time to do the install in “optimal” weather (i.e. not 100 degrees and raining). It’s kind of a “back burner” project that I’ve had going for a year or two now, but I’ll eventually finalize it, probably this spring.

That said, I spent a ton of time the other day looking at various GPS-oriented software for the PalmOS after finding out this old site I looked at a few years back, TheSupplyNet, a supplier of various cables for PDAs and cell phones to connect to one another, was still around, and they had a cable to go from the Tungsten T|2, the PDA I have, to a dead-end serial port… for connecting to something like a GPS, or maybe a TNC, but we’ll get into that next. A light went off in my head and I went in search of PalmOS 5 HiRes compatible software… although Garmin, has released Palm-compatible software for their GPS 10 Bluetooth GPS receiver, I’m kinda skeptical at the price they list. If they’d release a PalmOS viewer for MapSource maps, I’d be more inclined to drop the cash for that, as I have some MapSource software now.

Anyway, having turned up essentially no luck in the hunt for PalmOS GPS software, I turned my focus to another… APRS, or even just general packet, software for Palm. The quintissential Palm APRS client is PocketAPRS, but sadly that seems to have vanished off the web. Another solution I thought of using is APRS/CE, a client for Windows CE PocketPC. I have an old HP Jornada 520 P/PC, and I can verify that APRS/CE runs on it. So I might use that as a solution, if I can find a combo serial/DC cable for the Jornada… SupplyNet doesn’t sell one, so I’ll need to look elsewhere.

Of course, all these things are a few months down the line as I need time to figure out just how the heck I’m gonna do this.

And on top of all of this, I want to go HF mobile again! Somehow, I find ways to spend money even without trying. -_-;

Ham Radio26 Apr 2005 10:48 am

To introduce a new category, I present a post on an oft-discussed facet of amateur radio: EchoLink.

I overheard someone at work the other day mentioning how neat it is and how it can be a good way to get young people interested in ham radio. The way he described it sounds exactly like the instant messengers I’ve been using for, oh, 7 years now? As a young person, if someone used that to try to get me interested in ham radio, I’d probably tell them that I’m already using something that doesn’t require me to take a test and get a license to use and that all my friends are using already. EchoLink is cool in principle, but the method some people are using to promote it just doesn’t seem to hold much value to me.

So you want to get kids interested in ham radio, but you’re going to mention to them something that’s very very similar to something they’ve already been using for a while? Give me a break. Show them something that’s really cool(TM) and that would grab their interest and not let it go. Sadly, I don’t think EchoLink is going to do that. An IRLP-equipped repeater, however, might. If I tell someone I can talk to someone on the other side of the world with my handheld through the local repeater, they might go “Cool!” and inquire a little further into it. But if I tell them that I can use my computer to talk to the same person without using a radio at all, well, it just doesn’t hold the same kind of impact, as they’ve probably been doing that for a while already.

But, of course, why just limit these VoIP-based ham solutions to the method to get a kid to “catch the bug.” Why not use HF like has been done before? When I’m sitting in my car in the parking lot talking to someone in Russia using nothing more than 100W and a relatively inefficient antenna… well, that’s just undeniably cool.

So you want to get kids involved in ham radio? Stop trying to merge it with the ‘net and mimic their beloved IM and actually do something. After all, you can do voice (and even video!) chat in AIM now. So what’s the big deal with EchoLink?

Don’t even get me started on the attitudes a lot of the “elder statesmen” of ham radio have with regards to kids getting involved in the hobby. I don’t know about you, but if some old fart told me to get off “his” repeater because I was born 5 seconds after him, well, I’d probably be left with a really bad taste in my mouth about ham radio. For the record, I’ve met some young hams who are far and away more knowledgable and active in the hobby than the previously mentioned “elder statesmen” who do nothing but sit around all day on their favorite frequency and talk about their gallstones and other afflictions. I don’t know, but that’s not interesting at all to me. But, it’s not my problem.

And people wonder why I don’t get on the air much… >_>