Cheap Serial GPS Device

Wandering around Maplin on the off-chance they might have something interesting (does occasionally happen!), spotted this little GPS gizmo reduced to £19.99 - Gobalsat GPS Director GD-101, Maplin order code A30JN - on sale until 24/12/2009. Also findable on ebay, not quite so cheap at time of writing.

I had to buy one out of curiosity....

Looking at the back I spotted some test points, so naturally had to give them a poke with the scope probe... As I suspected, one of these provides a NMEA GPS data output...

Output is at 120kbaud (generally close enough to 115K2 to get away with it...), 3.3v levels, active-low.

I fed it straight into an FTDI TTL232 cable. 

Sample output

$POEM104,0,034,,000.0,999.9*09
$GPRMC,164253.000,V,5639.5142,N,00014.5032,E,0.0,0.0,091209,,,N*7E
$GPGGA,164253.000,5639.5142,N,00014.5032,E,0,00,0.0,,M,,M,,0000*66
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,2,1,08,32,79,076,,20,68,240,,11,65,144,,17,24,314,*72
$GPGSV,2,2,08,14,14,036,,28,09,252,,23,07,189,,31,06,104,*75

Impressively little inside..... M-Star MSB2122 chip and a few power supply components