Setting up APRS for Wheeling n' Stuff

[rover67]

Next i'll try to message another HAM directly using APRS and their callsign. that'll be for another day. Also, my mobilinkd is at home and i'm on Phoenix, so when I get back I'll get it all and start playing with that and a HT as the data link rather than the internet.

 

[rover67]

Not sure it's clear, APRSdroid requires its Mapsforge files to use version 3. This has been depreciated to newer version (5 is current latest). So if you download maps from openandroidmaps you need to specifically find the V3.

Those got compiled about a month ago and they are being eliminated from the website, so early in 2020 they will be removed completely. I opened a support ticket with Georg about pulling in a newer Mapsforge library to support V4/V5 maps but it's not currently in the OSM version.

Also, FWIW, I downloaded the complete set of US and Canada from openandroidmaps.com so if anyone wants the Utah-Colorado (or any other) I can get them to you now or in the future. They'll just slowly fall behind the OSM database with additions and corrections but should be fine for a few years. That's the main problem with the KS9N monster map, it's several years old and will have errors.

Dave,

Do you toggle between maps when using that set by changing what the solo file is in the aprsdroid.map folder? I assume it will only pull from one file at a time. Yeah the monster map has errors, its also empty in some places like where we were in montana for outlaws last year.. I have been perusing it for several days, but i think it may work for orienting myself on other maps... or ultimatly i'll integrate with backcountry navigator or something.

 

[DaveInDenver]

Regarding data radios with more than 5 watts. They exist. It's something Motorola and other commercial companies have made from time to time to support utility trucks and cop cars that have data terminals. They are fairly pricy and kind of a pain to deal with operating and programming so I don't think the benefit for ham is there. It's better IMO to just buy a decent plain old 2m radio even if you dedicate it to data use.

 

[DaveInDenver]

Dave,

Do you toggle between maps when using that set by changing what the solo file is in the aprsdroid.map folder? I assume it will only pull from one file at a time. Yeah the monster map has errors, its also empty in some places like where we were in montana for outlaws last year.. I have been perusing it for several days, but i think it may work for orienting myself on other maps... or ultimatly i'll integrate with backcountry navigator or something.

No, I have a folder on my Android device with all my maps (actually it contains all maps, mapsforge, PDF, etc). I point every app to this shared folder. With APRSdroid if you look in the app setting (or preferences, I forget what it's called) it has an option to pick a file. The "aprsdroid.map" thing is just a default setting. If you don't do anything else the OSM version will fall back and find that. APRSdroid does not automatically slip maps as you move though so you have to go into the settings and pick a new map as you cross state boundaries. Since the openandroidmaps guy(s) drew a boundary around Colorado and Utah that particular map happens to work 99% of the time for me. But if I go to Kansas, NM, AZ or Wyoming I have to manually select those maps in APRSdroid.

 

[rover67]

got some goodies in the mail!!!

 

[Stuckinthe80s]

got some goodies in the mail!!!

View attachment 82799

Nice! You should put those in your stocking and pretend they’re from Santa. They should fit nicely next to the lump of coal.
Would you be so kind as to post up part numbers and such and what not?

 

[rover67]

yeah for sure, I'm getting there! I want to verify what i'm doing works then post up what I did with the details. Right now i am fighting a UV-3r baofang radio that has a kaput battery..

 

[DaveInDenver]

Dave,

Do you toggle between maps when using that set by changing what the solo file is in the aprsdroid.map folder? I assume it will only pull from one file at a time.

Version:
APRSdroid
1.5.0-49-g378bdb9
2018-11-18

At the bottom of preferences you can point directly to the map file. The app by default finds the file "aprsdroid.map" in the root directory but I can't say for sure if this preference was originally blank or actually had "/sdcard/aprsdroid.map" there.

Yeah the monster map has errors, its also empty in some places like where we were in montana for outlaws last year.. I have been perusing it for several days, but i think it may work for orienting myself on other maps... or ultimatly i'll integrate with backcountry navigator or something.

That big map was compiled July 2013 and used Open Streets Maps as the source database. There's a couple of issues with this, basically that it's 6 years old from an open source database that relies heavily on regular users to input data.

It's good and in my experience sufficiently accurate when the data is there but unless someone has mapped and entered it won't be there. USGS, USFS, BLM and other primary sources (such as state agencies) for what we do generally aren't putting data there directly (it's usually stored on an ESRI/ArcGIS map feature server, maybe one that's a clearing house at FedGov if you're lucky).

Garmin maps aren't necessarily perfect either but since they rely on commercial databases (HERE/Navteq and Tele Atlas) they often are more complete and up to date with county roads and less traveled routes. That's a major difference when you're paying handsomely someone to collect, map and transpose information compared to a voluntary collaboration (it's generally referred to as "volunteered geographic information" or VGI geomatic data). If it's only you and maybe a rancher or two driving a road every year there's next to zero probability it'll be in OSM unless you do it or maybe, just maybe, a county GIS intern did it.

Personally I've added maybe a hundred miles of single track and roads to OSM based on my GPS tracks and a couple of times based on updated satellite overheads. Some users upload tons of data (there are commercial companies that do, more so outside of the U.S.), others just some, most none. OSM is ultimately only as good as the data that get puts there.

Point here is that 6 years is a really long time for OSM data so as a baseline KS9N is fine but it leaves a lot on the table.

 

[rover67]

Ahhhhh that's totally easier than changing what map is in a directory with a particular name on it. I was figuring it had to be named a particular way but what you did makes total sense. So to change maps I just point it to a new map file. Duh.

 

[rover67]

Ok so I finally got it all hooked up (one wire lol) and was able to run the rig in the car to see how it did. Overall I’d say I am happy. It tracked me on the tablet on the monster map just fine. That’s of course just using the tablets’ GPS so I would expect it to keep a good log of my position.

I’ll likely pull the other maps in and use them but for now the monster map works fine.

On the drive from breck to frisco it looks like it only picked up a few of my locations. You can see here is the screenshot from aprs.fi on my phone showing the relatively coarse track.

I’m pretty sure that the limited amount of data transmitted to show location was the fault of using this super cheap super low power 3watt baofang ht INSIDE the car with no external antenna.

Here is how I had the HT and the Mobilinkd TNC setup in the car, it is totally not ideal. BUT it still kinda worked.

Also, for what it’s worth... sitting in the house in breck I had good access with the HT to a digipeater near breck and was able to easily send and receive SMS messages. I also tried messaging Perry who was off doing something in the swell but I don’t think he had that part figured out or set up and it fell on deaf ears. Oh well we’ll try it another day.

 

[rover67]

So the setup is super simple. Super friggin simple.

It is as follows:

1.) An HT I had lying around which is a Baofang UV-3R and is since discontinued. I think it was a 25$ radio. You could use any HT though and the Baofang s are cheap but there are better name brand options out there....

2.) The TNC2 from mobilinkd. This is basically a modem that connects to the radio via the audio connections and to the tablet via Bluetooth. It is internally powered via a battery or externally through a mini USB port on the side. The TNC2 is about $70

https://store.mobilinkd.com/products/mobilinkd-tnc2-2

3.) The appropriate cable to connect the TNC2 with the radio. The mobilinkd store has several and I just got one from them.

4.) The galaxy tab A 2019. This thing was about 110$. You could do all of this with iOS but it sure seemed like the android apps and hardware are way more refined. Also the tables has a simple micro SD card for expansion.

In order to make it work better I think I either need an external antenna for the radio or a more powerful mobile radio coupled with an external antenna. I’m currently working on getting a spare Mobile radio I have setup to transmit/receive the 144.390 aprs frequency so I can build a cable for it and hook up the TNC2 to it and play around.

I’m thinking I love the tablet with APRSdroid interface to the TNC2 because it gives me super simple mapping and messaging functionality. That being said I’m leaning towards a permanent solution that will include either a dual band radio with one side working APRS or just have another radio in the truck dedicated to APRS. I think if a person wanted to do the latter it’d work well with a decent HT and an externally mounted antenna.

So anyways that’s where I’m at.

 

[rover67]

So my version of APRS Druid seems to have lost the field references below in preferences. I not only lost my map but I can’t find the field to re-enter the location of it on my SD card.

Tried reloading the latest version off of the website and still have the issue. I wonder if it’s got a big or if I need an older version?

Version:
APRSdroid
1.5.0-49-g378bdb9
2018-11-18

At the bottom of preferences you can point directly to the map file. The app by default finds the file "aprsdroid.map" in the root directory but I can't say for sure if this preference was originally blank or actually had "/sdcard/aprsdroid.map" there.

View attachment 82820

That big map was compiled July 2013 and used Open Streets Maps as the source database. There's a couple of issues with this, basically that it's 6 years old from an open source database that relies heavily on regular users to input data.

It's good and in my experience sufficiently accurate when the data is there but unless someone has mapped and entered it won't be there. USGS, USFS, BLM and other primary sources (such as state agencies) for what we do generally aren't putting data there directly (it's usually stored on an ESRI/ArcGIS map feature server, maybe one that's a clearing house at FedGov if you're lucky).

Garmin maps aren't necessarily perfect either but since they rely on commercial databases (HERE/Navteq and Tele Atlas) they often are more complete and up to date with county roads and less traveled routes. That's a major difference when you're paying handsomely someone to collect, map and transpose information compared to a voluntary collaboration (it's generally referred to as "volunteered geographic information" or VGI geomatic data). If it's only you and maybe a rancher or two driving a road every year there's next to zero probability it'll be in OSM unless you do it or maybe, just maybe, a county GIS intern did it.

Personally I've added maybe a hundred miles of single track and roads to OSM based on my GPS tracks and a couple of times based on updated satellite overheads. Some users upload tons of data (there are commercial companies that do, more so outside of the U.S.), others just some, most none. OSM is ultimately only as good as the data that get puts there.

Point here is that 6 years is a really long time for OSM data so as a baseline KS9N is fine but it leaves a lot on the table.

 

[rover67]

Figured it out somehow my app updated to a version that didn’t have the offline map functionality... removed and installed the version previously on the tablet when I started all this. Same version Dave had in his post.

 

[DaveInDenver]

Figured it out somehow my app updated to a version that didn’t have the offline map functionality... removed and installed the version previously on the tablet when I started all this. Same version Dave had in his post.

Did you happen to load APRSdroid at some point using the Google Store online version? The offline OSM version can only be loaded manually and isn't available through the normal app channel, so it shouldn't update on its own. So if you happened to have at some point put it on through the automatic loaded I wonder if ever using the regular version got a revision in the Play Store and that prompted it yours to update, overwriting the OSM version with the latest official version.

 

[rover67]

Did you happen to load APRSdroid at some point using the Google Store online version? The offline OSM version can only be loaded manually and isn't available through the normal app channel, so it shouldn't update on its own. So if you happened to have at some point put it on through the automatic loaded I wonder if ever using the regular version got a revision in the Play Store and that prompted it yours to update, overwriting the OSM version with the latest official version.

I think that's exactly what happened... I need to learn android better so I can keep that from happening int he future. I ended up keeping a copy of the OSM version in a location on the SIM card so I can reload it if it turns into a problem and I don't have good cell coverage/internet availability.

 

[DaveInDenver]

Over here: https://risingsun4x4club.org/xf/threads/confession.27884/page-11#post-342732

Marco posted an image of a maiden voyage of his 80 with an APRS posit track. I trimmed off the non-APRS parts of his post.

Second, the APRS works a treat. Sent a message to my honey. She got it.

I don't know if it was intentional but wanted to highlight that his APRS client posit algorithm parameters are set to beacon waaayyy too fast.

Did an analysis using a minimum packet spacing of 30 seconds (red) and a more network friendly one of 120 seconds (green). Just one met that criteria and a few (the yellow) fell in the marginal range. These are only the packets that reached APRSIS, so each packet will on the air have 1 or 2 others immediately after that were transmitted by the digipeaters that heard him.

Why is this important? He was seeing several digipeaters, at least 6 I think. Which for the most can see each other and other digipeaters further out. I didn't check to see how many other stations were active, but in Denver-Boulder it's probably several dozen. Each packet he transmitted had the WIDE1-1, WIDE2-1 set, which means they might do 2 hops, e.g. be retransmitted twice potentially.

An APRS packet transmission could be 1/2 to a second long and so each packet bouncing the repeaters around might consume several seconds of network time. At a fixed packet timing of 30 seconds one station will consume about 50% of the a typical 1200 baud network's bandwidth. With some of these position beacons coming in 15 seconds that means Marco was effectively consuming nearly all the network bandwidth.

APRS is shared, so just wanted to highlight that by calling out Marco because I know he can take it and I also know he's knows better. ;-)

Position beacons shouldn't be any more frequent than about 120 seconds and 5 to 10 minutes might be a nice gesture in a crowded network for a non-critical application.

 

[AimCOTaco]

Good points Dave, since APRSdroid has "SmartBeaconing" setting which is nice in that you can set it to catch turns and direction changes and change behavior based on your travel speed.
I have my Digi path set to WIDE1-1 only and here's is a screenshot of my SmartBeaconing settings..

How does this look:

 

[DaveInDenver]

Thanks Andy for your settings. I was going to add "What am I supposed to do then?" next. That's not a simple answer, though.

First thing to realize is the digipeaters are generally pretty smart. You'll see some of the iGates reported packets were coming in too fast or were duplicates, for example. A lot of digipeaters use Kantronics TNCs and they are quite good at intelligently routing traffic.

Not all do use them and not all TNCs are well done as far as being good network routers. Especially uncoordinated digipeaters (e.g. fill-in stations) or random iGates can be configured wrong and muck things up worse. In this case more isn't better, strictly speaking.

Behind the scenes there's alogithms implicit in the WIDEn-N paradigm to proportionally path your packets and they know about each other at higher levels, regionally for example.

Point being your packet isn't just blindly repeated. Digipeaters know where a packet comes from and where it needs to go or if it needs to stop.

One thing that Marco could have done is not asked for a wide coverage since I think he was only interested in getting positions to the Internet with whatever iGate could hear him. Just setting WIDE2-1 (dropping WIDE1-1 off the front) should prevent retransmitting packets widely.

Normally for mobile you want to use Smart Beaconing like Andy is showing. This adjusts your beacon rate to speed and turning to make it appropriate. If you're going 15 MPH you can go longer between beacons than 65 MPH. I also set an absolute floor of 60 seconds normally but when off road and unlikely to hit many digipeaters I'd say 30 seconds is fine.

If it's just two trucks in the backcountry doing a floor of 15 seconds is fine. But its like voice, you need to leave gaps even doing simplex in case a 3rd ham wants to get in to talk or especially if he or she has a mayday. So just my $0.02 but 15 seconds is excessive.

 

[rover67]

Where'd you go get all that info Dave?

It was not my intent to go nutso with it and consume all the network bandwidth. I am not interested in sending packets every 15 seconds or even every 30. personally something like 60 seconds even more would be fine. My intent it to coarsely communicate my position in a reliable way that other Mobile APRS stations could receive and utilize that info. Also so it could be visible on the internet.

Anyhow, I started by using the settings that were recommended here:

http://www.mobilinkd.com/wp-content/files/MobilinkdTNC20c.pdf

In particular here is the section I am referencing in case the link breaks....

1. Set your SSID. SSID 7 is common for hand-held radios.
2. Set your APRS symbol. If you don't know which one to use, choose /[ for now. That will put a “jogger” symbol on the map for your position. See also http://www.aprs.net/vm/DOS/SYMBOLS.HTM
3. Personalize the comment field.
4. Under “Location Source”, select “Periodic GPS/Network Position”.
5. Under “Location Settings|GPS Precision”, select “Low”. If this device connects to a mobile phone network, select “Use network position”.
6. Under “Connection Protocol”, select “TNC (KISS)”.
7. Under “Connection Type”, select “Bluetooth SPP”.
8. Under “Connection Preferences|TNC Bluetooth Device”, select “Mobilinkd TNC2”
9. Under “Connection Preferences|APRS digi path”, enter “WIDE1-1,WIDE2-1”
10. Enable “Connection Logging”

So for example that "WIDE1-1, WIDE2-1" setting was specified in that .pdf. Now admittedly I did not know exactly what it meant so this is supremely helpful.

I am also using the "Smart Beaconing" setting like Andy, though it may have different settings...... I will go double check in the garage in a bit. I really thought i had set it to beacon at a reasonable rate but I may have gotten it wrong..... well obviously I did..

 

[DaveInDenver]

4. Under “Location Source”, select “Periodic GPS/Network Position”.

This setting is the critical part. That's where you can tell APRSdroid how often to send a position. What Rob is telling you in that TNC2 manual is to do a fixed position time, e.g. every X seconds or minutes. There's I think a field to tell the software that interval.

This is fine for testing and if you're setting up a fixed position station (like at home or a repeater site) doing a status every 30 minutes or whatever is absolutely acceptable. There's a concept with APRS (and networking in general) call "net cycle time" which is how often any individual station should expect to hear all the other stations in the network before making the assumption to start rolling off stations that have left the network.

IOW most software will give a window before removing a station that's no longer heard. In a tactical situation the APRS network controller (like if you're at an event or doing emergency communication support) will be something like 60 minutes so your individual station needs to update more often than this with some certainty. So you might want to do 6 updates per hour to allow for the statistical chance some number will not be heard due to a collision with another packet or being at the fringe.

You can swing the other way in doing 60 per hour and getting 60 valid means you did 59 too many. But if there's a lot of stations and everyone is doing 60 per hour all you're doing is flooding the network will garbage and you might still only get 1 valid per hour because of interference and stepping on each other.

APRSIS and aprs.fi have net cycle times of hours and days and in the case of aprs.fi your packets or some of the data within are stored for months and years. So there's no reason to send a lot of beacons for the Internet if the intention is just a "Hey, I'm here". APRS isn't supposed to be used in place of recording your own GPS track or using a Spot or InReach for periodic tracking. It can support that to some extent and using the network capability is fine but the system isn't designed to support everyone doing high update rates, so we have to share is all I'm trying to say.

That's where Smart Beaconing comes in. Sometimes you want to pack beacons close together, like when you're turning a lot in canyons. But if you're on the Interstate one every 10 minutes is more than enough to get your point across.

So for example that "WIDE1-1, WIDE2-1" setting was specified in that .pdf. Now admittedly I did not know exactly what it meant so this is supremely helpful.

I am also using the "Smart Beaconing" setting like Andy, though it may have different settings...... I will go double check in the garage in a bit. I really thought i had set it to beacon at a reasonable rate but I may have gotten it wrong..... well obviously I did..

Setting your path around Denver to "WIDE1-1, WIDE2-1" is just fine for normal use. You want small footprint fill-in stations to repeat your packets and for the main digpeaters and gates to give you regional coverage without overwhelming the network.

Out here I use "WIDE1-1, WIDE2-2" usually because the network isn't burdened with a lot of stations and I want potentially 3 hops from a fill-in and two backbones to find an iGate to APRSIS. But even that said "WIDE1-1, WIDE2-1" has a pretty good success rate in the middle of the Sinbad Desert with a 5W radio and 1/4λ roof whip so there's really nowhere *that* remote anymore.