After some trouble with my SMS sending routine I am finally able to show some working code.
Features so far
- Displays menu via serial port if attached to PC
- Can run unattended or interactively for debugging
- Fetches GPS positions and sends them via SMS every two minutes
If the circuit is powered on, the following sequence will be executed:
- Boot up, switch on the GPS-GSM module
- Initialize the modem
- Fetch the GPS position, redo until position is fix
- Parse and format position
- Send formatted position as link to Google Maps as SMS
- Wait 120 seconds
- Goto 3
Well, now you have all information and sources to rebuild and program this device, at least you should. If not, please tell me, what is missing.
But I had some hints in the comments that this can be done easier with the built-in Python. There also other very promissing sources and that is definetely the next thing, that I want to try out. If that works fine, which is not really doubtful to me, I could drop nearly all the external components. That would make it cheaper, easier and smaller.
Nevertheless, the firmware can be useful, if you would like to see, which commands to use to talk to the Telit module.
- Part I: Interfacing an AVR controller to a GPS Mobile Phone
- Part II: Using Google Maps with a mobile GPS tracker
- Firmware on github: beacon