Kicking around an idea for APRS.

psykokid

Explorer
I mainly got my HAM ticket to have better comms than FRS could provide when offroading. Now that I have my ticket and stumbled upon APRS I've seemed to find a new rabbit hole to fall down into.

For right now I just have a UV-5R along with a nice Diamond NR770HBNMO on an NMO mag mount. Decent send and receive for a small radio with only 4W. Eventually I'll get a mobile rig, something like the Yaesu FTM-350AR with the GPS module. Although it's been discontinued used units pop up from time to time. Spending that on a mobile rig isnt in the cards at the moment

For the time being I want to get an APRS setup up and running. It will help me keep my wife in the loop when we're out in the middle of no where (she's a worrier) without the expense and fees of a SPOT or similar. I was thinking about either getting an all in one transmit only solution like Byonics Micro-Trak RTG FA. All said and done it's $220 plus shipping with an antenna and gps puck. Not too bad but it kind of side steps one of the great features of APRS which is the ability to communicate both ways. I've seen APRSdroid which is a nice implementation of APRS over cellular data using APRS-IS. Thats all fine and dandy but when you're out in the middle of no where there's usually no cell signal. Turns out there are a few other features in APRSdroid which includes AFSK which allows you to connect an audio cable to your android device and then connect the other end to your radio to send out over your radio. I found an implementation of it HERE using just a Baofeng UV-3R and an android phone. Not too shabby..

This got the wheels a turning. How about using a bluetooth adapter like a Pryme BT-501 with a UV-5R? I already have a Samsung Galaxy Tab2 7" that I use when offroading for mapping. The Pryme BT-501 adapter is setup for Kenwood radios which the Baofeng UV-5R seems to use the same type of connector so that should work there. Find a cheap mag mount antenna for the roof, pick up the BT-501 adapter which i've found for around $90 shipped and another UV-5R for $30 from amazon along with the APRSdroid app and i should be good to go. I figure I could have a solution for around $150 all in.. I could go with just a cable solution and keep it even cheaper but I don't need more wires and crap inside the cab of the truck. Using bluetooth and keeping it wireless will help me from keeping the inside of my truck looking like this:
messy.jpg

Any comments or suggestions?
 

Rando

Explorer
I have played around with APRS and other amateur radio gizmos some and my conclusion is this - if you want this to be a hobby go the APRS route, if you want it to be a tool (that just works) go the delorme in-reach/spot route. Before I get flamed, I am not saying there is anything wrong with APRS, but you have to enjoy the tinkering that goes along with it (disclaimer - I currently have a home brew Iridium/Raspberry PI two way tracking system in my vehicle!)
 

Crom

Expo this, expo that, exp
For the time being I want to get an APRS setup up and running. It will help me keep my wife in the loop when we're out in the middle of no where (she's a worrier) .... Not too bad but it kind of side steps one of the great features of APRS which is the ability to communicate both ways.

Just to be clear, unless your wife is a licensed amateur, she can not send you messages on APRS. And strictly speaking it would be illegal for you to try to communicate with her over APRS if she is not licensed. She could obviously, like anyone else, monitor your location through one of the Internet APRS linked sites. APRS is fun and I've played with it using APRSDroid. If I wanted to use APRS over RF today, I may spring for the new Kenwood TM-D710G which is new and has a GPS receiver built in. Pricy--yes, but it's all in one, and no wire mess!

Also, I agree with Rando, in that if I needed to get messages out to loved ones I'd use an alternate form of communication such as renting a SAT phone or other type of comm.
 

nat

Adventurer
I have played around with APRS and other amateur radio gizmos some and my conclusion is this - if you want this to be a hobby go the APRS route, if you want it to be a tool (that just works) go the delorme in-reach/spot route. Before I get flamed, I am not saying there is anything wrong with APRS, but you have to enjoy the tinkering that goes along with it (disclaimer - I currently have a home brew Iridium/Raspberry PI two way tracking system in my vehicle!)

I was just wondering about teh rasberry pi and Ham radio. Any link or info on your setup?
 

Rando

Explorer
Unfortunately I have not written up my setup, and I am not actually using ham radio, but an Iridium satellite phone. The hardware is a raspberry pi, a Venus GPS module for position and an Iridium 9555 sat phone. The software side is simple - GPSd running to interface with the GPS module and a simple python script to put the GPS coordinates in the right format and send them out using SMS on the sat phone. The sat phone has a built in usb-serial interface, so it appears as a serial port on the RPi and you can control it using standard GSM AT commands.

I was just wondering about teh rasberry pi and Ham radio. Any link or info on your setup?
 

psykokid

Explorer
Just to be clear, unless your wife is a licensed amateur, she can not send you messages on APRS. And strictly speaking it would be illegal for you to try to communicate with her over APRS if she is not licensed. She could obviously, like anyone else, monitor your location through one of the Internet APRS linked sites.

Good point about the licensing issue. Good excuse for her to get her ticket :) If i were going somewhere I NEEDED comms out in the middle of no where then a sat phone or inreach/spot would be the ticket. I found out long ago that my own sanity went hand in hand with keeping her well informed as to where I was going and a rough ETA back home.
 

DaveInDenver

Middle Income Semi-Redneck
You can send APRS messages without being licensed, just not via RF.

Go to http://www.openaprs.net and under 'Tools' there's an option to send messages. The main hurdle is that messages are not stored, so if the recipient does not have his radio on the message just ends up in no man's land. But it will bounce around and get to you no matter where you physically are located if in range of an APRS-IS digipeater.

Getting a message back to an unlicensed person is more difficult. You could send a message to yourself I suppose and they just watch the exchange. Or you can also send APRS messages to/from email.

http://www.aprs-is.net/email.aspx

It's not as slick as texting or something, but there are gateways across services.

Talking to an unlicensed person is more difficult, although there is Echolink. You can connect your radio to a computer acting as a node, although it's kinda skirting the rules. Nah, who'm I kidding, it's not legal. But it's possible in an emergency for you on a radio to talk to someone with only a computer.
 
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DaveInDenver

Middle Income Semi-Redneck
Also don't misunderstand, APRS like all of ham radio is about tinkering and experimenting. Most anything is possible one way or another, but just not necessarily packaged into an easy-peasy no-thought required device. OTOH most of it just costs your time behind a soldering iron and monkeying with configuration files. A lot of hams are involved with emergency communications so things like APRS are even occasionally used for real, which is why we mess with it the rest of the time, to make sure it works when activated by FEMA or the county EOC.

My current goal is to interface a tablet with my new FTM-400, which came with a USB interface cable from Yaesu. It looks like I'll be able to use Backcountry Navigator as the basis for a tactical display with local stations showing up via RF. The problem I have is that the tablet needs its own GPS because Yaesu doesn't allow waypoints and NMEA streams simultaneously (just like the FTM-350 unfortunately). Yaesu also doesn't have a full TNC built into the FTM-400 (again just like the 350) so messaging is constrained to the radio only. But the FTM-400 does have a nice virtual keyboard, so it's not bad at all. But to run something like APRSdroid you'd need an external TNC, which is an unfortunate kludge IMHO.
 
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HenryJ

Expedition Leader
KISS

I too thought about all the bells and whistles that can be APRS. In the end, I went with the MicroTrak RTG.
mt-rtg-3.200.jpg

Turn key installation $220. Easily moved from vehicle to vehicle, however it is usually just forgotten and does its thing in the Avalanche. Turn the key on and it works. Get home, hit the maps, and see EVERYWHERE we have been.

flake.jpg


Rides under the back seat where I installed an ignition hot power port. You can just see it under the gold dune flag poles in this picture.
molle.JPG


The cell phone and 2m offer enough communication options for us right now. APRS is way down the list. Maybe if the cell was gone, I MIGHT consider using text messages via APRS? For now I am at my "happy place".

I would suggest getting APRS going , now. Don't wait and speculate. Keep It Simple...

EDIT: I looked a little closer at the Moblinkd option. It does look pretty cool. Worth playing with for sure. All together $72 (cable, TNC, app) add a radio to that ($50 cheapie) and you are in under $150. It will not function independent of the Android OS. Not a stand alone unit in that sense. Still looks like fun and worth some testing. I have several little Wouxun radios around and this might be a good thing to try with one of those? Right now my gut says the MicroTrak RTG is a better option for a KISS vehicle APRS solution.
 
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Crom

Expo this, expo that, exp
The Mobilinkd has a huge advantage over something that just beacons your location. the Mobilinkd can decode received packets and plot them on the Android device maps. That's huge! Some guys are shelling out $600 for an AVMAP GPS that does the same thing. Very cool! Thanks for the heads up.
 

HenryJ

Expedition Leader
The Mobilinkd has a huge advantage over something that just beacons your location. the Mobilinkd can decode received packets and plot them on the Android device maps. That's huge! Some guys are shelling out $600 for an AVMAP GPS that does the same thing. Very cool! Thanks for the heads up.
Worth further investigation for someone who enjoys tinkering. I'm in :)
Still seems like quite a bit to go wrong. The investment starts to add up if you need to buy a radio , external antenna, 12v power adapter for the radio, cell phone, power adapter for the cell phone.
Now you have to have someone on the other end listening to those sent packets. That means investing in another one for the wife or son.
Might all be well worth it? We will see.
 

chris snell

Adventurer
So I ran APRS on my last truck and I'll eventually set it up on this truck. In general, it worked pretty well. My original vision is that me and my friends would all run it and we'd use it to rendezvous out in the desert late at night. That never happened, mostly because they couldn't be bothered to get it going. We stuck to 2-meter simplex for the late-night link-ups. I did, however, get some use from it as a tracking beacon to provide a little reassurance to my wife when I was out on a multi-week offroad adventure. She would check out aprs.fi every evening to see where I'd been that day.

Here's what I use for my setup:

Argent Data Systems T2-301 with integrated 5W Friendcomm radio. The newer T3-301 model is out now but the basic function is the same.
Diamond Antenna NR770HB
Diamond Antenna thin cables (the RG316 stuff) for easy routing
Garmin GPS18 puck-style GPS receiver - very low-profile and very good at picking up signals even with overhead cover

I used a Blue Sea Systems fuse block that was switched by a relay to my ignition accessory line so that the APRS tracker turned on every time the car was on.

Here's a photo of my T2-301:



There is a really nice feature of the Argent Data trackers that I made use of: you can hook up a Dallas Semiconductor 1Wire temperature probe to the tracker and it will include a temperature reading in your APRS transmissions. I used a Maxim DS18S20 digital thermometer:

ds1820-1-wire-temperature-sensor.jpeg

The DS18S20 is not waterproof, so I built a small enclosure from some thin steel, which I soldered shut and capped with silicon sealant:



There are commercial waterproof options available but they're pricey and the DS18S20 sensor is only a couple of dollars.

I tucked the sensor discretely away in the fold of my soft top:


The end result is APRS beacons with the outside temperature from wherever I'm driving. It's a fun way to remember icy mountain passes that I crossed late at night, or hot days out in the desert.

 

Crom

Expo this, expo that, exp
Saw this two days ago.
 

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