Using bluetooth GPS dongle with any device is in fact nothing more than sending clear text (NMEA protocol) over serial port:
1. BT device (dongle) announces it's serial port (virtual serial port - Bluetooth SPP/SP profile) 2. BT client connects to the dongle 3. Dongle opens serial connection and send stream of NMEA data. That's all!
So let's see what NEO can do:
- We got device equipped with GPS
- We got very powerful bluez stack and utilities
- We can get NMEA data
- We can announce Serial (SPP/SP) service using bluetooth
- and finally... we can bind GPS port with BT port and redirect NMEA to any BT client that would like to read it :)
- We can share GPS data with anyone (Phone/Smartphone/PC/Laptop)
- Maybe sending that data to more than one person (I don't know the exact BT capabilities)
- Whenever you want you can use your PocketPC powered with Automapa or TomTom and don't have to buy another GPS device
- many many more :)
I've made few tests on desktop debian and was able to get data with Holux GM-101 Handheld GPS (USB Cable) and Nokia N70 (BT)
0. Prerequisites: connect GPS unit, setup bluez and remember to pair your devices!
1. Make BT listener: rfcomm listen 0 (on my system it binds connected device to /dev/rfcomm0)
2. Announce your SP service: sdptool add sp 1
3. Run some GPS aware application on your client device
4. On successful connection rfcomm will say something like:
Waiting for connection on channel 1
Connection from 00:**:**:**:**:** to /dev/rfcomm0
Press CTRL-C for hangup
5. cat /dev/ttyUSB0 >/dev/rfcomm0 (where /dev/ttyUSB0 is my USB to serial converter connected to GPS)
6. Should work :D
If you can connect but there is now data:
- use "cat /dev/your_gps_device" to see if GPS is sending NMEA data to PC (for examle in holux you have to switch some options in menu)
should look something like this:
- check paring
In a thew weeks time I should get my new Forerunner, so I will try to move this idea to Openmoko platform.
Freerunner as GPS bluetooth device
This is described here: http://wiki.openmoko.org/wiki/GPS#GTA02 It allows to use the freerunner as ordinary BT GPS reciever. BT aware devices like navigation systems can then use the freeruners GPS signals.