On gpsd, obdgpslogger, and udev hotplug

**chunkyks** · 10-15-2009, 10:44 PM

So, finally I have obdgpslogger and gpsd both working with udev hotplug, on ubuntu 9.04

My USB OBDII devices are FTDI.
My USB GPS device is pl2303.

1) Making gpsd work

a) Copy /lib/udev/rules.d/40-gpsd.rules to /etc/udev/rules.d/40-gpsd.rules
b) Edit /etc/udev/rules.d/40-gpsd.rules. Comment out the line for idVendor 0403 and idProduct 6001, and modify the two pl2303 lines so that the permissions will let gpsd access it:

Code:

# Prolific Technology, Inc. PL2303 Serial Port
SYSFS{idVendor}=="067b", SYSFS{idProduct}=="2303", SYMLINK="gps%n", MODE:="0666", RUN+="/lib/udev/gpsd.hotplug.wrapper"
# ATEN International Co., Ltd UC-232A Serial Port [pl2303]
SYSFS{idVendor}=="0557", SYSFS{idProduct}=="2008", SYMLINK="gps%n", MODE:="0666", RUN+="/lib/udev/gpsd.hotplug.wrapper"

c) Edit /lib/udev/gpsd.hotplug.wrapper
Take out the line

Code:

. /lib/udev/hotplug.functions

and put this there instead:

Code:

wait_for_file() {
        [ -e "$1" ] && return 0
        local count=0
        while sleep 1; do
                let count=count+1
                 [ -e "$1" ] && return 0
                if [ $count -gt 60 ]; then
                        return 1
                fi
        done
}

d) sudo dpkg-reconfigure gpsd
Launch on boot - yes
Leave the automatic device list empty
Should gpsd handle devices automatically - yes
Options to gpsd: "-F /var/run/gpsd.sock"

2) Make obdgpslogger hotplug work

a) Put this in /etc/udev/rules.d/40-ftdi.rules

Code:

SUBSYSTEM!="tty", GOTO="ftdi_rules_end"
ACTION=="add", SYSFS{idVendor}=="0403", SYSFS{idProduct}=="6001", RUN+="/usr/local/bin/obdgpslogger -ms /dev/%k"
LABEL="ftdi_rules_end"

b) Configure obdgpslogger to do what you want
Edit /etc/obdgpslogger [if it doesn't exist, just create it]. Set it to put the logfile in the right place:

Code:

log_file=/media/usbthumb/carlog.db

If you have a device that defaults to 38400 instead of 9600 [eg, an OBDLink], then you also need to put that in the config file:

Code:

baudrate=38400

The obdgpslogger half is covered in a bit more detail in doc/auto_launch in your svn checkout

Gary (-;

**tripzero** · 10-15-2009, 11:48 PM

great job. I'll do this inside LinuxICE to make things easier.

will obdgpslogger automatically create the path to the db?

**chunkyks** · 10-15-2009, 11:59 PM

Oops, forgot to add a thing about gpsd permissions. Fixed.

Gary (-;

**chunkyks** · 10-16-2009, 12:01 AM

OBDGPSLogger doesn't automatically create a path to the db. The default is "./obdgpslogger.db". If you want it set to something else, that's what the config file /etc/obdgpslogger is for.

Gary (-;

**chunkyks** · 10-17-2009, 12:14 PM

Oh. And if gpsd.hotplug.wrapper doesn't exist on your system at all, try this one:

Code:

#! /bin/bash
# $Id: gpsd.hotplug.wrapper 4669 2008-01-21 15:07:00Z esr $

#debian addition:
[ ! -r /etc/default/gpsd ] || . /etc/default/gpsd
[ "$START_DAEMON" = "true" ] || exit 0
[ "$USBAUTO" = "true" ] || exit 0


if [ "$ACTION" == "remove" ] ; then
  if [ $(echo $DEVLINKS | grep -q /dev/gps) ] ; then
    exec /lib/udev/gpsd.hotplug "$ACTION" "$DEVNAME"
  fi
  exit 0
fi

# . /lib/udev/hotplug.functions
wait_for_file() {
	[ -e "$1" ] && return 0
	local count=0
	while sleep 1; do
		let count=count+1
		 [ -e "$1" ] && return 0
		if [ $count -gt 60 ]; then
			return 1
		fi
	done
}

# wait for /usr & /var to be mounted
wait_for_file /usr/bin/python && \
wait_for_file /var/run && \
  exec /lib/udev/gpsd.hotplug "$ACTION" "$DEVNAME"

Gary (-;

**Bugbyte** · 10-21-2009, 07:58 AM

Configured everything except for the obdgpslogger part. I don't have /etc/obdgpslogger in my directory (step 2b).

What does that mean? I've never run obdgpslogger before?