[Gta04-owner] gpsd software
Dr. H. Nikolaus Schaller
hns at goldelico.com
Sun Dec 4 21:02:53 CET 2011
Am 04.12.2011 um 01:28 schrieb Neil Jerram:
> I just wanted to point out that the latest gpsd (3.x) has a nice feature
> that I believe allows providing GPS on demand with no need for an
> "enable GPS" switch or something like "fsoraw -r GPS ...".
> That is, it calls a hook script (/etc/gpsd/device-hook $DEVICE ACTIVATE)
> when the first client connects on the gpsd port, and similarly
> ((/etc/gpsd/device-hook $DEVICE DEACTIVATE) when the last client
> disconnects from that port.
> For GTA04, I think that means we can put the commands to enable and
> disable GPS power into that script, and then just run gpsd all the time.
That is really a nice feature!
One thing we have to consider - the reset impulse for the
GPS module is a toggle switch. Each impulse toggles between
power on/standby. And the only method I know to detect
in which state it is is to check if there are NMEA records
on the serial line.
The GTA04 tester sends one impulse and waits up to 5 seconds
if there arrive NMEA records. If not, it sends another impulse.
I don't know if that can be done by this type scripts and gpsd.
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