Okay, it's time for the demo. KG7OOW here with the Ham Radio Village. Let's get going on APRS
and a quick walk around on usage of every aspect. So, let's get going.
So, APRS, the Automatic Packet Reporting System, is based on the AX25 protocol from the
1980s. Pretty old. Another slang term for this protocol you may have heard is packet.
Packet is basically another use of this. We're going to dive into more of the APRS route of this
and some of the basic usage. So, we'll go from the APRS website, how to see APRS. You won't need
a license to do this. We are going to go to the end user, someone transmitting APRS from a
handheld mobile. And we'll also take a look at a DigiPeter, vital parts of the APRS network that
get your message to other DigiPeters or to an iGate out on the internet to be posted online.
So, let's first take a look at where I go. This is where you are going to see APRS traffic live
for your area. There's two main websites. Let's dive into the first one. So, this is aprs.fi.
For those of you who haven't been here, it's a great resource to see live APRS traffic.
We'll zoom out here. Let's go to the Las Vegas area, Defcon Central here, and see what's going
on. So, when you come to the site, it'll first probably throw you somewhere in Finland. You'll
have to navigate to where you want to go. The right hand side will let you select how much
traffic you want to see. Do you want to see traffic for the last hour? Do you want to see
the last traffic for the last day there? So, plenty of information to see. We're mainly going
to focus on the map here though. So, here's the Vegas metro area. There's all these icons about.
We got, looks like an RV icon down here in the middle. Driving around is RV. Broadcasting APRS
packets. We have weather stations. We have other objects on the map, such as DSTAR repeaters
and things like that. Like N7ARR over here. Zoom is not working great on the video. We'll
get some more details later there. And then, here we are outside of Vegas. My favorite mountain,
Mount Potosi. This is home to the Vegas DigiPeter and EyeGate. So, it's definitely
really cool to see all this on a map. And again, you don't have to be licensed to
view this map. It's definitely a great resource. So, this is what I go to when I am looking for
who's coming through my area. What are they doing? Are they listening on a frequency that
I might want to talk to them on? Mainly for vehicles here. But, if we pan out into the
desert, a lot of the times you'll see planes. You'll also see weather balloons and other
things like that going across the map. So, definitely keep an eye out for those.
Let's perchance see if there's any weather balloons or anything going across right now.
I do not see anything up. They typically do launch every couple weekends though
out here in the West Desert. So, definitely something to keep an eye out on.
Okay, let's look into detail on some traffic. What are these users... what are these objects
sending to the APRS network? So, here's a car out in the West Desert going just past...
let's see... just past the test site over there. We have K6VFA and he is cruising along the highway.
We can see the time stamp of the data. We can see his heading, his speed, his altitude,
any GPS metadata that that radio is capable of putting out. He has a little message,
MikeENroute, and he is repeated by the Vegas Mount Potosi repeater. If we zoom out here,
we'll know... we can kind of visualize how his packets are getting to the internet map here.
Oh, come on. It is not wanting to clear. So, if you hover over an object... oh, come on.
It is not wanting to work for me here. There we go. Let's get out here. Okay, see? So,
I'm hovering over his icon there. You can see it's going through the Vegas DigiPeter
up on Mount Potosi down in the bottom middle there and looks like it's going to another eye
gate. Maybe the eye gate there at Potosi is down. So, these eye gates that it's going to transmit
to can be hundreds of miles away. Looks like that's down in the San Bernardino Valley.
So, that's a pretty crazy run for some APRS traffic.
And when you get to things like weather balloons, you'll have
hundreds of stations picking those up directly. But the first station that picks it up is the
one that gets to report it to the system. So, another really cool map to hit up when you're
looking for some APRS action is APRS Direct. It's more of a
high-end web 2.0 type interface. It's got live updates. The icons will update live. You'll be
able to see pings on the map when things happen as they're happening. So, sometimes it's a little
easier to see things here. This is kind of a newcomer to APRS maps, which is great. Here,
let me throw a link there in chat for you guys, what I'm going through. So,
this map, very similar to the last map, it's just a little more interactive.
We got the same amount of data. You can see hops that these packets are going through. You can
click on an object. There's our same guy we're going to be picking on here, K6VFA. He is
cruising along. There's his same path. He's being reported through Vegas.
And his timestamp, same information, bearing, heading, things like that.
So, this is just a really cool, very awesome way to see what's going on with the APRS network.
Now, how do you get traffic to the APRS network? So, this traffic, including weather stations,
handheld radios, mobile radios that are APRS capable, or anything else you can think of,
they all require a modem-enabled device or just a fully integrated APRS device to get out there.
One of the easiest ways to get into it is with an integrated radio. So, let's look at
my handy Kenwood THD72. It's a great... here we go...
It's a great little radio. Not really little. It's a little bulky.
Needs to go on a little diet there, but it's an all-in-one solution to get your packets
out to the APRS network. This particular handheld can be used with the built-in GPS
with the antenna on the top there. It can also be connected with a cable to a weather station
or other KISS-enabled device. So, it's very cool, very fun to hear APRS going on.
So, it looks like someone's keyed up on APRS, but
sounds like voice data. Someone's got a hot mic. So, the APRS frequency you're going to want to
dial to on your all-in-one inclusive device is 144.390 in North America. I haven't gone
through APRS on any other countries, so I'm not 100% sure if they're throwing other frequencies
around for other regions, but definitely 144.390 for North America. Now, tuning into this frequency,
you're going to hear the raw APRS packets. They are going to sound
very much like an old classic modem. I don't know... it sounds like I'm getting some
interference or someone's hot micing 3.9.0 for me, so I'm not going to be able to decode anything.
Yep, just static. So, I'm thinking I got some interference, but with this handheld,
I can beacon directly just by hitting beacon here, and it will manually beacon my location
based on the GPS to the APRS network. I'm inside, so my GPS likely is not going to get my coordinates
and without proper coordinates, I don't think it will show up, but just in case, let's go
look for KG7OOW. I am not showing up, so there's definitely some traffic around, though.
So, with a handheld like this, we get to configure it. So, out of the box,
need to configure your handheld with typically just your call sign. So, I just go to the menu,
hit up APRS, and it typically just needs your call sign. So, you throw your call sign in there.
Oh, there we go. You'll typically just throw your call sign in, maybe a SSID
at the end. See that dash nine at the tail end there? You can do that if you have multiple radios
or if you want to have a specific ID for that radio. And then you'll basically just need to
tell it how to beacon. So, on this handy can book, we got... here we go...
where is it going? You can set your position manually and you have beacon. So, this is how
it's going to beacon your information. Typically, on a handheld like this, you can set it to
beacon on an interval, or you can have it beacon using what's called smart beaconing,
and that will automatically beacon you based on your speed and your heading. So, if you take a
turn, you change speeds, it's going to broadcast your APRS data accordingly. So, it's really cool.
Little handhelds are great, but definitely on the pricey end. So, this Kenwood THD72,
had to look that up there, is... I think I got this around 500 bucks, so it's definitely pricey.
It's definitely capable, but there's other options out there. So, let me slide this over
and give kind of a cheaper option. So, one other cool option is a standalone unit.
I got this handy AVRT5 from Amazing AliExpress. These little things, all inclusive. It's only
one watt of power, but you'd be surprised how far you can get out with APRS on one watt of power.
This handheld, this Kenwood, I've gone probably 150 miles,
is pure line of sight. So, this was definitely to a mountaintop digipeter. I was out in the
Nevada desert and was able to get to a digipeter in central Utah. So, that was really cool.
But this little one watt Chinese, kind of hard to configure radio, is actually pretty handy.
I got hands here that will either throw, just leave it alone, or throw a linear amp on it
and get a little bit more distance out of it. But definitely something you can throw into
your backpack, hiking, on your bike, in your pocket. So, it's very cool. Very,
very nice little slim device here.
Another option when you're picking end-user APRS equipment is definitely
an app called APRS Droid for Android. So, APRS Droid, I haven't gotten to work on the latest
version of Android, but most ham software, you're going to expect that. You can get little,
this is called a micro-linked TNC, and it's just a little 3D printed case with basically
a Arduino Nano inside. And it connects via a little 3.5 millimeter jack there
to an adapter cable to your radio of choice. So, it can be paired with a Baofeng, it can be paired
with another radio, anything you want. And it connects via Bluetooth to your phone. So, your
phone will be running the APRS Droid app, and very much like the handheld Kenwood, you get to
put in your call sign, you can put in icons that you want to put, and any messages that you want
to put as your beacon. Another really cool feature about APRS is not just GPS location, but messaging.
So, on my little Kenwood handheld here, I can send messages by, you know, using the keypad.
Pretty old school, kind of like how you used to have to text back in the day,
with the touch pad there. But the advantage of this cool little micro-linked
TNC with your APRS Droid enabled phone,
you can just use your Android phone, type the message and get it sent. So, it's much easier to
use this paired with a phone and a radio than to just use the radio if you're going to go the
messaging route. So, definitely something really cool. There's just, I always look on AliExpress
or Amazon for new APRS devices, and there's just, every once in a while they'll come out
with something really cool. So, that gets us around the end user devices, handhelds,
other dedicated units from China that may or may not have reporting capabilities for
the government there, to mobile-linked TNCs with your Android phone. But there's another
piece to this puzzle, and that's the stations that actually get that data, the packets that
these devices put out to other DigiPeters and eventually to the internet. And that's where
a DigiPeter comes in. So, this is a basic DigiPeter setup. I got these all over the state
here in Utah, and we have definitely increased the... here, let me zoom out here and we'll see
if we can... okay, we have definitely increased the APRS coverage in my region and hoping to
expand into other parts of Utah. So, this whole setup consists of a 2-meter radio. This particular
radio is just one I got off a surplus. It's an EF Johnson RS-5300 here, and all you need is a
2-meter radio that has connections on it for push-to-talk and for the audio mic and speaker.
Most radios you see out there will have this either through the front port jack here
or with a dongle or connection in the back. This one just happens to be done with a DB...
what, 15 connector on the back, DB9. And this just plugs in and gives me the breakout for audio,
push-to-talk, and that's all we need on the radio side. So, a 2-meter radio. It can also be a
handheld. I've seen people use bow fangs for this, so definitely something that can be done a little
cheaper. But this is a nice surplus radio. I got it for about $35-$40, so not too bad, not too shabby.
So this radio needs to hook up to a device that can decode these APRS packets. To do this decode,
I interface my Raspberry Pi with a EasyDigi. These are available on eBay and it comes in a little
kit. You have to solder it together, just a little more part of the adventure. All you really have to
do is solder two leads for the audio and the connections to your radio for push-to-talk,
things like that. So in this particular setup, I am using the GPIO for push-to-talk. You can also
just use VOX if you're using a handheld radio or bow fang. This particular 2-meter mobile radio
is not capable of VOX, so I definitely have to manually trigger push-to-talk, and that's where
GPIO on the Raspberry Pi comes in. So radio goes to your EasyDigi. The EasyDigi is basically just
an isolation. You actually don't need the EasyDigi. You can wire things directly. It's just
safer. You're not going to ruin your Pi with its low GPIO voltage,
and you're not going to screw up your radio, and you'll also get cleaner audio. So definitely go
with the EasyDigi. On the Raspberry Pi, it's fitted... since it only has a speaker output,
I wish they made this a four-pole connector with a mic input, but hey, you can always go to another
Pi variant like the Banana Cream Pi or something for that. I just fit my $35 Raspberry Pi
with a $4 or $5 USB audio card. So you can grab these on Amazon. I'll put a link in a little
write-up when we post this video. But you just take your microphone, plug it in, and your speaker
for your radio. Plug it in there, get it in the Pi, and you're good to go on the hardware side,
I guess, other than the GPIO. So GPIO is another step in the setup. The GPIO portion,
as well as the software portion, is covered in the documentation of the software I use,
we'll get into that right now. Let's go to the good old browser view here. So
my choice of APRS software for my Raspberry Pi or any other system is called Direwolf.
So we'll hit up Direwolf. I'm just going to use Google here. They have a great
set of documentation on GitHub. You can go through any doc on here, but the main thing
you need to do is go for the documentation on your system. So they have documentation for Linux,
they have documentation for Windows, and they have specific documentation for the Raspberry Pi.
So let me look here. So yeah, I'm just going to scroll down here just to
make sure I'm speaking the truth here. But there we go. Raspberry Pi for ham radio. So Direwolf is
going to be built on top of your Raspberry Pi. So you need to install
distro. I just use Raspbian for my Raspberry Pi. Get that installed on your Raspberry Pi and then
use the instructions from GitHub here, the documentation repo, to build it for your system.
Mostly it is literally just downloading the source and then compiling it. Once you've compiled it,
you can start right out and get it running. So let's go to console and see what
Direwolf gives us on the Raspberry Pi. What kind of information, what does it look like
when you're actually using Direwolf on a Raspberry Pi. I'll go and I'll probably post
maybe some quick dirty instructions for actually building a Direwolf kit
on the website hamvillage.org. But for now let's go cut to the end results. I think I'm
pretty low on time here and we'll go to the console here.
So this is what a typical putty installation, well not putty, this is what a typical terminal
of Direwolf will read out once you're up and running. You'll see traffic coming across from
mobiles, handheld units, and in my area definitely a lot of weather stations.
So there's a plethora of information here.
And we can pick, let's see, let's pick this latest one that came in.
So this was an iGate transmit looks like.
Okay that was just for that node. So let's go to this one AJ6KW. So AJ6KW with a destination of
APTT 4 came in with this path and looks like some GPS coordinates. So he came in with some
GPS coordinates positioned with time. He is using a tiny track so that's one of those cool little
all-in-one devices and it's spitting out his coordinates, course, and any other information.
It's really cool just to see how much traffic you're going to get on these systems
and the console. Let's see here's another one coming in. Looks like a jeep on a mobile unit
coming in here with some coordinates, course, altitude, and he's monitoring on 146520. So
looks like Keith and I can hit him up on that frequency, give him a chat, and
that's just really cool. The terminal here isn't necessarily the place you're going to
stalk people on APRS. Definitely use the web interface to do your stalking but
it's just really cool to see what your radio is hearing directly because again
the stuff posted on APRS.FI and APRS Direct, whatever station heard it first
is the one that gets to post it there. So you may have heard it but you may have not been the one
that reported it to the servers there. So it's definitely something definitely cool to see just
the raw data. And see here we go here's just an iGate transmit from Frisco, Frisco Peak,
just throwing a beacon out with its position and location and that.
This is AL7BX's rig, a good friend of mine. He has helped me a lot with this APRS stuff. We
definitely are working together to build out more APRS rigs in our area. So I think we're
pretty much up for time on the demo. The wonderful radiogram talk was amazing and
pushed us over a tad but no worries. Let's go answer some questions in chat if there are any.
I know this was kind of a droned out presentation live demo but let's see if there's any questions
either in Discord or in Twitch here. Give it a quick glance and we'll get going here.
Okay well definitely an earful. There's definitely more resources for APRS. If you
want to get into APRS, you want to carry it along with you or you want to expand the APRS
network yourself, go ahead and hit me up in the Ham Radio Village Discord on the Defcon server
or our own Ham Radio Village server. I'll throw links in chat. Just go ahead and I will even be
able to help you remotely. I've helped people with remote desktop to help set up their rigs so
any help I can give I'm just more than happy to expand and contribute to the APRS community.
So thank you everybody and we'll see you back for closing comments here in just a little bit.
Thank you!