Ubuntu Touch @UBports based cl compass. Tested on BQ Aquaris E4.5 aka "kirillin". It is running in my version of atlast Forth. https://github.com/skvamme/atlast Compile atlast on a raspberry pi and copy atlast and compass.atl over to phablet directory on the mobile using e.g. scp
The compass is programmable in Forth and can display values on command line, or as an SMS to someone or upload to a server on the internet.
If you are new to Forth I recommend reading this great book by Leo Brodie https://www.forth.com/starting-forth/0-starting-forth/
The compass has man overboard functionality. Current location can be saved and later, you can get distance and bearing to that saved place. It works equally well when you are "lost in town" and want to get back to your hotel. No maps or internet required.
Start the terminal app and start atlast with sudo ./atlast -icompass.atl Stop atlast with Ctrl-D
A word in atlast is in itself an executable piece of code, just type the word and press enter.
Usefull words are: init for calibration. run for compass. Both these words run until stopped with Ctrl-C. Just type the word and press Enter. When you run init you should move in all compass directions until no more changes are visible in xmax, ymax ... Then type Ctrl-C and type run
More words: save for saving the current location. berdist for getting bearing and distance to saved position. For these two words to be able to pick current gps location, type the word and press enter and switch over to the weather app or a map for a minute or so. These apps are activating the gps while visible so the compass can grab lat and long readings and do all calculations in the background.
If - when you switch back to the terminal app - it says that the app is stopped. Type fg to get it back in foreground again.
You will see lots of 0 and -1, and at end of last line is the result. 0 and -1 are for debugging.
The word send-sms can be used to send current location, saved location or other message as an SMS.
The word smspos grabs current lat and long and sends that as an SMS. To let the compass grab the current position, switch over to the weather app or a map for a minute. The GPS icon in the top screen should light up.
Replace the dummy phone number with a valid one in the file compass.atl or if you want to change the number temporarily you can redefine the word smsto in the running atlast: Type : smsto "the_number_here" ; Mind the spaces. Atlast will always use the latest definition of the word smsto. And forget all of them when you switch of.
The word tcppos is sending current position over the internet to a server, replace the current ip-address and port in file compass.atl with a real one. The word tcprun is sending compass heading to a server once every second. Break the command with Ctrl-C.
NOTE: If you are trying to upload to a server that is not responding, the compass will terminate.
On the server host you can use netcat, like this to listen at port 8080 nc -l -p 8080 -k
Word for saving gps tracks is writetrack. The file save.gpx can be imported into many mapping applications. Running until GPS data stops, so switch from weather or map for 10 seconds or more. Go back to weather and the gpx file will be complete with ending XML-tags and file closed. Make sure the phone is set to never lock the screen when you are recording a GPS track. Locking screen will stop GPS recordings.