What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

APRS: The Next Generation

petehowell

Well Known Member
Hi Guys,

The Alpha and Beta testing is over and the first long XC is under my belt with the next generation of APRS for the RV World...............

GEEK ALERT - this is not for the plug and play crowd - but if I can do it, you probably can, too.

APRS has a lot of very cool capabilities beyond dropping the bread crumbs that many of us already do. It can send messages, it can track and plot other units, and it can send telemetry. Anyone interested in an RV mounted solution that can do all that??? Read on!

The trick was to assemble a unit that had a user friendly front end and a capable back end/radio section with out killing Kate's college fund. Some digging on the web found that an Argent OpenTracker2 ($95) can be paired with a Garmin Nuvi 350($100 refurb), a 2M transceiver($big range), and some cables ($50)to give you a really spiffy set up. The Garmin has a built in messaging interface (Fleet Management Interface)that is tapped into to enable APRS messaging.

I bought all the stuff, and wired it up - I wanted to make the unit portable, so the back end goes in a bag. The Nuvi350 is at the bottom:

Rush%20City%20034.jpg


Nuvi is mounted on an articulating stalk on the right side of the 9PH panel. Hey look, I hacked the Nuvi to add a plane icon and I loaded a custom data base of all US airports. The Nuvi has limited flight planning capabilities- it might even drive the ADI Pilot II. Yep, that is the local digi plotted on the screen...

Rush%20City%20039.jpg


Hey, can I use this thing to send me an email?

Rush%20City%20040.jpg


Yes, I can!

Rush%20City%20041.jpg


Unit in Action - I have it on the pass seat here, but for XC, it lives right behind the seat. Unit is configured for 5 Watts, and heat is not an issue in the bag. How do I know? - I can query the unit from the Nuvi, and it will report internal temperature!

Rush%20City%20043.jpg


Can I receive messages from other people while in flight ?

Rush%20City%20085.jpg


Yes, I can!

Can I find and plot other APRS equipped airplanes in flight?

Rush%20City%20154.jpg


Yes, I can! That's Alex P on my wing in 66AP.

Oh, hey - can I still drop breadcrumbs so Grandma can track us?

Location%20of%20KD0CVN-1%20-%20Google%20Maps%20APRS%20-%20Google%20Chrome%20722009%20120510%20AM.jpg


Yes, I can!
Notice it reports the unit internal voltage and temperature as telemetry....

Ok - this thing is pretty cool - but it is probably overkill for the plane. It weighs a few pounds and cost a few bucks. But it can send an email or text message from 10,000 feet!!

It requires much more work to assemble and configure than the Microtrak and costs a fair bit more. If you want a cheap, easy, light weight tracker, get a Microtrack from Byon and be done. However, if you want to tinker, don't mind some frustration, and want to be the undisputed biggest geek in the hangar - try this set up, then blog of me highly.......:D
 
Last edited:
Geek Heaven

Nice report Pete...It looks like you had a good time with it.:)
Dan
 
antenna

Hi Kent,

I have tested with a J-pole and an external whip. Coverage seems to be about the same.

This unit listens before it transmits, so the bread crumbs are not as uniform as with the Microtrack. I can override that from the Nuvi in cockpit if i want to force transmissions.
 
Nuvi 350

The NUVI 350 is the only unit in the Garmin line that will work with the adaptor and the OT2, so you should buy the 350's while you can still find them. None of the other Garmin fleet vehicle interface units will work.

Allen
VHS
 
That does it

You are the undisputed king of Geeks....Now start making them smaller and sell me one..:)

Frank
 
Garmin nuvi 350 referbs available radio shack online 109.00. Allen is this doable with mtt4 and nuvi?

The sentence converter that Argent data built for the NUVI sends and receives NMEA data, so his converter should allow the use of the NUVI with any APRS or communication device. The converter sells for 48.00 bucks. The Argent website is showing a couple of GPS receivers it will work with.

We never developed a lot of interface stuff for the Garmin products since they are notoriously hard to work with. Instead, we will focus on the Avmap product line, which is actually designed to work with APRS, and will display all the icons unique to APRS. It speaks garden variety NMEA and Kenwood language, which the MT-TT4 emulates.

Pete's setup is very cool, but you can do much the same with a MT-TT4, which weighs about 5 ounces and is about 4 X 4 X 1. You can plug in a real PC keyboard ( a mini keyboard for you guys!) and a remote alphanumeric LCD display for sending E-mail. The next version of the software will allow you to do all your programming with just a keyboard, no PC required. You can also connect any display GPS receiver that sends and receives NMEA or Kenwood.

I have to say, that being able to send E-mail from a vehicle (for free!) is pretty cool. Personally, I like real keyboards instead of Celphone style or LCD keyboards, which I could never use while driving without crashing most egregiously!

Allen
VHS
 
Pete's the APRS man!

I hope to see you at Oshkosh or Homecoming or...just passin thru, we're riding motorcycles to Oshkosh so we can hit Sturgis on the way back. Thanks for getting me on the APRS path!
 
Gotta agree with Allen

The Nuvi key board is a bit of a pain, but it is self contained. It is also nice in that it pops right out of the plane and goes in the car. It will hold pictures and plays MP3s, too. If I ever take it out of the plane, It will go in my commuting car. If you are interested, pick one up soon - the refurbs are all that are left

I have been asked a few questions about the mount. I used some Loc-Line and JB welded it to the Nuvi mount. I embedded a 8-32 screw in the Loc-Line and that screws into a panel mount hole. It works pretty slick!

Here are some pics:

IMG_7762.jpg


IMG_7764.jpg
 
Hacking the Nuvi?

Hi Pete,

Can you share some information on how you hacked the Nuvi?

Thanks,

Dave
 
Pretty Easy Dave

The Cirrus airplane can be downloaded from the garmin site and uploaded to the Nuvi.

I went to a POI (Points of Interest) site and downloaded a POI file of all the airports. I then used a garmin converter to get it in the right format. I loaded this file on an SD card and plugged it into the Nuvi. Booya - you have kinda sorta an aviation GPS for a 100 bux.

Let me know if you want the file - I'll send it to you for a soda:D

Cheers,

Pete
 
Last edited:
Messaging

I had 6 hrs in the saddle yesterday to play around with APRS messaging. It was great for letting people know where I was and my ETAs. It seems to reliably get messages out.

It is a bit cumbersome to launch an email and you are limited to about 60 characters. Also the messages are in the public domain, so say if I was the chief executive of one of the Carolinas, I'd want to make sure to keep things brief and be sure to address them to my wife;)

It was fun to fly over Chicago at 150kts and see the Nuvi tell me I was approaching a new street every second or so:D

It works pretty much as advertised - cool, but it has limitations.
 
Status message change

One other cool feature I discovered - you can change your staus message from the nuvi - so I can put my flight plan in for each XC. The packets can print something like:

N789PH/RV-9A KANE-KJOT-3HO-3TR

I just need to remember to change it.......after I land.
 
Refurb'd Nuvi 350's...

...back in stock at RadioShack.com, for anyone who's interested. Just received mine, works great!

Dave
 
cool capability

On the trip out west I was able to change my APRS comment from the cockpit.

We were dodging wx on the way out, so i updated my comment with the new route.

18:31:37 - 18:31:37 UTC: KD0CVN-1: 07.9V 22C n789ph kane-krap
22:06:28 - 22:06:28 UTC: KD0CVN-1: 07.8V 23C n789ph kcpr kcag ksbs
23:03:34 - 23:03:34 UTC: KD0CVN-1: 07.8V 16C n789ph ksbs kane direct!

Kinda like a in-flight, real time, broadcasted flight plan.
 
Pete

whats the procedure to change the status message via the nuvi . I seem to have everything else working ok but cant seem to find the way to change the status message.

on my way to buy soda i guess

Regards
Gary Holderbein
KI6PIY
 
Here you go Gary!

This is what I use in the cockpit. I change the comment on the "fly"(sorry)

cheat%20sheet.JPG


Kudos to ham Mike Wren for the nice cheat sheet!

I don't think I can get a soda for posting someone else's stuff.
 
tracker 2

Pete

Thanks got it working now except when sending messages even with retries set to 4 . Seems if no ack. is rec. that it continues to keep resending mesg. until I delete from out box . Any chance you have a screen shot from config. set up you could email me .Just maybe there is some setting I have overlooked.
very nice chart from Mike Wren Thanks Mike was a big help .(dashes who would have thunk it :rolleyes:)

Regards
Gary Holderbein
 
Pete
Well if you cant get it to get a ack. from a sent mesg. I'm sure it wont worky. I think maybe setting --retrytime might work just in case you forget to remeber you sent one . what you think ? even with the bugs pretty cool setup .

Regards
Gary
 
Cheap Nuvi 350

Ecost has refurb Nuvi 350's for $85. Great price for an APRS front end unit that will give you 2 way messaging in the cockpit.

Pair it up with a tracker2 and a mobile radio. Not plug and play, but great capability.
 
Back
Top