I'm actually excited about the baro sensor. I'd love to modify the code to see frequent baro reports and positions reports. My thought is that flights are so short that it won't be on the network for long, and many might be interested in seeing telemetry from a rocket on APRS. Certainly it's novel.
Can't wait to get mine, and try it out.
73,
Les Rayburn, N1LF
Ahhhhhhh, Does the device have onboard storage? If not you'll have to be satisfied with APRS updates once every 5 seconds and you might not receive all of the position packets via Rf. The thing in your favor though is the 300mW output, the fact the
propagation on the 2 meter band is better than 70cm and 33cm and the fact you'll have the option to use a 2 meter Yagi (3 element is about all that is easily hand held) will increase the odds of successfully decoding packets.
There is a video of a multi-stage rocket going to extreme altitude and the camera is shown monitoring the screen of the Multitronix receiver. The Multitronix is not an APRS system but is actually more optimized in my opinion for
high frequency rate updates. That device it is said, sends data out at 5/sec although I don't know if that is the altitude readings 5/sec.
It appears there are periods of delay when the altitude is unwinding on camera. Granted, the delay is shorter than I've observed with other systems but many times with one every 5 seconds APRS updates, I've seen no discernable positions sometimes for 10 to 20 seconds on the down side. Sometimes it's once every 5 seconds but not every Rf packet is decodeable. Higher transmit power and better receive antennas improve the chance of accurate decoding but don't get your hopes up for getting "totally" reliable high rate data over the Rf link via APRS. You'll have plenty of information to find your rocket so don't fret that.
When I used to APRS track on a laptop with Xastir in Linux, even with the once every 5 seconds updates the bread crumb trail on the map was most helpful. I'm hoping to give it a go with Xastir on a Pocket Chip in the future.
https://docs.getchip.com/pocketchip.html#pocketc-h-i-p-at-a-glance One ditches the Pocket Chip firmware and flashes Debian "Jessie" that's available on the Next Thing site. The Pocket Chip runs fine.
I loaded Xastir and some basic maps and Xastir takes awhile to open but it does work. I've got the NMEA EggFinder trackers working with it by piping the incoming NMEA strings into a python script that makes it into an APRS packet. Just select "allow networking" in Xastir, run the script in a plain x-term while Xastir is running and minimize the terminal. The EggFinder is seen on the Xastir map like a pseudo APRS icon.
Here is the link for the script:
https://www.ece.uah.edu/~jdw/rockets/gps2aprs.txt One has to change the .txt to .pl, edit their particulars as explained in the comments and its possible to use an NMEA tracker with Xastir.
Just put the location the receiver resides (ex, /dev/rfcomm0) in the appropriate statement in that script. Another funky thing is the script can put a number on the icon. I have the number 8 appearing on the body of the rocket icon.
I haven't seen that before in any programs actually.
The Pocket Chip has the potential of running APRS too via a Bluetooth TNC. Xastir has the ability to put a lot of information next to the icon on the map including groundspeed, bearing, track and altitude along with bread cumbing the track and saving the positions for repainting later on the program. Can save a variety of logs simultaneously including a .kml file. Just go to the directory, grab the .kml and loft it to Google Earth. No conversion program to run.
If one wants to do APRS on a laptop, get UI-View and find a torrent of the maps for offline maps and one will have much the same capability as Xastir except UI-View allows one to record in real time the flight. Only program that does that. One can playback the flight in real time any time they want. No other APRS program does that. Only problem is bluetooth connectivity in the latest WinBlows leaves everything to be desired. It really sucks and one might be stuck with a wired TNC which can be a drag as is running a full sized laptop out in the field. The issue is with UI-View is the author died and refused to disclose the source code. It's frozen in time.
APRSIS-32 on a tablet is very workable and can deal with the infernal WinBlows bluetooth issues. The program itself can work with bluetooth TNC's and GPS (for local) position. I've used it a lot on several different tablets
satisfactorily. It can save a variety of maps but there is no longer a MapQuest photomap set for it. There are a variety of Open Source maps for it that can be cached on a microSD card for offline use.
On WinBlows tablets I have mine setup like a laptop desktop. I can't get used to Micro$$$$ interpretation of a tablet. A mouse is a must. Wear black pants and you can run a wireless mouse on your pants leg or get a handheld mouse. I use a mouse with the Pocket Chip too as it doesn't have a touch screen.
Out of all the programs out there APRSIS32 might be a little easier for a new person to learn. Extensive online database and the user group is very helpful and don't mind answering elementary questions. This program
can be hacked for use with NMEA trackers like the EggFinder and Missileworks. So I only have to have my WinBlows tablet(s) and I can use them with my APRS and NMEA trackers. One program good for both formats.
(As is Xastir too but perhaps a higher learning curve with that one.)
Sorry to be long winded but I really enjoy the ease of finding a rocket with live map tracking when one gets the system down pat. You start toying with a live tracking remedy and master it to a degree,
it makes tracking a totally out of sight flight less stressful and actually enjoyable. Kurt