The GPS hardware I'm using with my Raspberry Pi, if sent the command $CDCMD,33,1*7C, will report the status of the antenna connection.
I'd like this command to be issued whenever my GPS daemon starts. My current config file at /etc/default/gpsd looks like this:
# Devices gpsd should collect to at boot time.
# They need to be read/writeable, either by user gpsd or the group dialout.
DEVICES="/dev/serial0 /dev/pps0"
# Other options you want to pass to gpsd
GPSD_OPTIONS="-n"
# Automatically hot add/remove USB GPS devices via gpsdctl
USBAUTO="false"
# Start the gpsd daemon automatically at boot time
START_DAEMON="true"
Is there anything I can add to this config file to insert either the antenna command, or the path of a file containing the command?
I've searched all over for documentation for the config file, yet all I can find is example file, nothing that fully documents what options are available for configuration.
Alternatively, if the gpsd daemon is already up and running, and already has control of the serial port used to communicate with the GPS hardware, is there a way to send an NMEA command that gpsd will pass along to the hardware?
The only way I've been able to test this command was to shut down gpsd, then run minicom to issue the command to the hardware directly.