Playing with bluetooth GPS for fun and profit

I am recently fiddling with an old Bluetooth receiver to use it as a time source for my Arduino chrondot clock. Please note it’s already been done[wyolum.com] and an interesting graph of Chronodot drift is provided.
First of all I decided to get a good look at the NMEA stream coming out of the GPS unit.
It’s quite painless on recent Ubuntu (thanks westernwillow):


$>sudo hcitool scan
00:1C:81:55:1C:A1 iBT-GPS
$> sudo rfcomm bind /dev/rfcomm0 00:1C:81:55:1C:A1 1
$ ls -l /dev/rfcomm0
crw-rw---- 1 root dialout 216, 0 Nov 19 14:41 /dev/rfcomm0

Now we have a valid serial device we poll with minicom ($>sudo apt-get install minicom)
We have to change the serial device in minicom configuration $>minicom -sminicom bluetooth serial setup

The minicom bluetooth serial setup

than save and fire up minicom and you should see a stream of NMEA.
$PMTK0XX0,00XX*XXE
$GPGGA,XXXXXXXXXXXX.XXXXXX,XXXXXXXX.XXXXXXXX,N,00XXXX0.XXXX0XX,E,0,0,,XXXXXX.XX,
M,XXXX.0,M,,*XXXX
$GPGSA,A,XX,,,,,,,,,,,,,,,*XXE
$GPGSV,XX,XX,XXXX,XXXX,XXXX,XXXXXX,,XXXX,XXXX,XXXXXX,,0XX,XXXX,XX0XX,,XXXX,XXXX,XX
XXXX,*XXC

This would be an interesting step on itself to have an handy precise timesource using gpsd and ntp
Next step is to assert if the following is suitable [arduino.cc] for me.

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