gps-glonass-android-driver

GPS/GLONASS generic android driver for serial devices. (gps.default.so)

It uses ro.kernel.android.gps, ro.kernel.android.gps.speed and ro.kernel.android.gps.max_rate kernel parameters.

Installation

Just copy the library to /system/lib/hw/ folder add properties to build.prop and reboot device.

Kernel properties

build.prop example:

  ro.kernel.android.gps=ttyUSB0
  ro.kernel.android.gps.speed=9600
  ro.kernel.android.gps.max_rate=1

Properties description

ro.kernel.android.gps - [REQUIRED] Device name
ro.kernel.android.gps.speed - [NON REQUIRED] Baud rate. Supports: 4800, 9600, 19200, 38400, 57600, 115200. Default value: 9600
ro.kernel.android.gps.max_rate - [NON REQUIRED] Maximum refresh rate. Between 1-10Hz. Default value: 1

IMPORTANT Higher max refresh rate causes higher CPU load. Recommended value is 1Hz (car navigation, etc)

init.d script

On some devices the library cannot set baudrate itself, in that case you can use the folowing script. Call it 00_gps.sh, save it in init.d folder, add 755 permisions and root as an owner.

#!/system/bin/sh
# GPS Switcher
# init.d 00_gps.sh
# dipcore@gmail.com

GPSTTY=/dev/`getprop ro.kernel.android.gps`
SPEED=`getprop ro.kernel.android.gps.speed`

if [[ ! -z $GPSTTY ]] ; then

	# Default speed
	if [[ -z $SPEED ]] ; then
		SPEED="9600"
	fi;
	
	# Serial device params
	if [ -c $GPSTTY ] ; then
		echo "Setting USB GPS $GPSTTY speed to $SPEED"
		# Speed
		busybox stty -F $GPSTTY ispeed $SPEED
		# No echo
		busybox stty -F $GPSTTY -echo
		# Owner
		chown root:system $GPSTTY
		# Permissions
		chmod 666 $GPSTTY
	fi;
	
fi;