GPS Serial Data via Audio Downlink

[workshop]

Gotta tackle this one...

I want to use my choice of moving map software, one that accepts serial data from, say a Garmin GPS18LVC, to a serial port on the laptop.

I like Ozi Explorer so far for many reasons...
http://www.oziexplorer.com/

I have an audio downlink but the solutions I've researched used APRS "packets" and requires software to read such... Naw, I just want to modulate and demodulate the serial stream (don't need no stinkin' packets) and feed that into the laptop via the serial port (if a hardware solution) or sound card (if a software solution).

http://www.byonics.com/tinytrak/
This will seem to work on the way down since it can be set to send NMEA strings.

http://www.cyber-flyer.com/
This guy uses it but uses ARPS packets and his own software to do the decoding... (too hard)

This seems like such a simple thing and so useful to have an otherwise unused channel serve to facilitate a moving map display. Has anyone had success with a solution or do I have to learn what APRS means? :o :rolleyes:

Jeff

[Mr.RC-CAM]

APRS would require the least amount of wheel re-inventing. Since it looks like you will be using the TinyTrak, and you have a laptop with sound card, all you need is the APRS driver and the map app. There are commercial and free maps that are compatible with APRS.

BTW, there is an endless amount of APRS info on the net that is available to ease the pain.

[workshop]

I would think that a simple serial modem would be all that is required?...

serial > sound > sound > serial... That's how computers talked before the Internet; over the phones with modems...

That's gotta be easier than APRS... And ARPS software is "lacking" compared to the many fine mapping programs out there...

Anybody have any 9600 baud modems left over from the "old days"...? This has got to be too simple to see...

Jeff

[Mr.RC-CAM]

And ARPS software is "lacking" compared to the many fine mapping programs out there...I haven't seen what is out now, but when I looked a couple of years ago there were a some popular map apps that worked with APRS. But, it sounds like you have looked into this and APRS is not what you want.

Anybody have any 9600 baud modems left over from the "old days"...? This has got to be too simple to see...If you go this route, you probably do not need modems at all. Unlike the 3KHz public switched telephone network, the audio channel on most video Tx's have a lot of bandwidth. A simple zero crossing detector with logic conditioning on the Rx end would probably be all that you need. I am not sure if you would achieve 9600 baud, but a reliable 4800 baud seems likely. That is plenty fast for mapping.

If you want to use modems, then maybe the old Cermetek or Xecom modem modules would be something you would like. They are very small. Probably available for pennies on ebay.

[workshop]

How do others do Moving Map?

I just guessed that "remoting" the serial GPS reciever (my case a Garmin GPS18lvc), i.e. splitting off the serial stream and modeming it to the ground and plugging it into the laptop's serial port.

Google Earth, OziExplorer, etc... even MapSource if I'm correct displays, as an icon, any GSP serial data stream that shows up at it's serial port.

I'll tackle this but I may need an EE willing to work for PayPal.... :rolleyes:

Jeff

[lvspark]

http://www.rcgroups.com/forums/showthread.php?t=367828&page=2&pp=15&highlight=arps

[workshop]

The list of programs on your graphic showed me compelling reasons to switch from OziExplorer (a non-APRS solution *forget about the APRS add on*). Thanks for the help... a picture is worth a thousand words... :rolleyes:

AGWTracker looks good... Why did you choose the UI package?...

Jeff

[lvspark]

I don't remember why I used UI-view.. It's been almost 3 yrs ago I did those flights.. It was a freebie..It had a tool to pull geo referenced images from the web (very cool at the time)... also was pretty easy to use any aerial image and add the geo tags to.. It recorded the flights for later playback.

I remember it working pretty well but not 100% solid all the time.. The audio was a bit touchy... If I wanted a moving map today, and the plane could lift a couple more ounces, I would use maxstream. They will run a few hrs on a std 9v battery...

I really liked balloon-track for windows but it was not aprs compatible..