Amateur radio - APRS reporting with Asset Tracker shield?


#1

I’m interested if anyone has thought about using the Asset Tracker’s GPS logging with APRS, the amateur radio position tracking system.

The end-to-end picture would look like this:

  • GPS on asset tracker shield
  • Cellular network on Particle Electron
  • Webhook listener that collects the position data
  • APRS-IS client that posts position data for the device to gateway (port 14551)

Alternatively, if someone has made a suitable VHF radio that could be used to transmit the GPS data, you could send position reports over the air.

I’m throwing this out there hoping that someone will 1) think it’s interesting and 2) have more insight into how to build the APRS client side of things, which appears to be documented only in code fragments.

thanks and 73,

Ed W8EMV


#2

Hi Ed,

A couple of years ago I did a high altitude balloon launch with an APRS tracker using an Arduino. Many have done the same.

Shortly after that I ported my GPS and APRS code (including the AFSK code) to Teensy 3.1. I got it to work, but never used it for anything. Code is here.

It turns out that I’m just starting on a project to do another balloon launch using a Particle product. I intend to port the code to the Particle environment soon.

As for a transmitter, I’m using the Radiometrix HX1. I bought it some time ago, and I’m not sure it is available in the US anymore.

Before I found the HX1 I simply fed the AFSK signal into a cheap HT (Baofeng). Sort of ungainly, but it worked.

Anyway, let me know if you want to pursue this any further with me. Happy to kibitz.

– Rich KC3ARY


#3

Hi Ed,

My friend and i are interested. We will be trying this shortly after our Electrons and GPS shields come in. I am also contacting someone that develops APRS trackers on arduino.

As you see rvnash and many people have done this using radios. You would not need the Electron for this.
rvnash i am also interested in using my photon connected to one of my radios. looking forward to the port!

Using a 2g/3g Electron would be great. Plus I’m curious how to connect to APRS via internet. The benefit the Electron would bring to the table is not needing outside components other than the GPS shield and power. It would be extremely small and clean. Just flash it add a box and mount it on your dash. Only thing is you couldn’t use it on balloon’s :frowning:


#4

I’ll share what I come up with, but it may be a little while.

So long as you don’t use the 2G radio during the flight, it’s fine.


#5

Thanks for the interest!

This code from Greg W2GMD might be of some use; it’s in Python

and has routines both for receiving from APRS and sending to APRS and for reading data directly off of a GPS.

73 de Ed W8EMV


#6

I uploaded a library I just wrote to send APRS position packets using TCPIP, or APRS-IS. I’ve tested it on my Electron only, but I’m pretty sure it would work on a Photon. Feel free to download from here: https://bitbucket.org/rvnash/aprs-is It should be fairly straight forward how to use it, but feel free to ask any questions.

I intend to write an AFSK version which will create the audio signal for sending a packet out over RF, but that’s a bit more involved and will take more time.

I hope this is helpful.


#7

Hi @vielmetti

I know it has been nearly a year, but I have finally gotten around to fixing up this project and making it work. If you, or anyone else is interested, I have code now which can generate the AFSK audio to transmit APRS packets. I have confirmed it works by successfully transmitting a few packets to some iGates in the area.

I have some cleanup and refactoring yet to do on the code before publishing it, but if anyone wants it now, I can share the repository with you.

73
Rich
KC3ARY


#8

Thanks Rich! I’d be happy to take a look at the project.

73 de Ed W8EMV


#9

Hi Ed,

Check out my announcement here.