Re: [gpsd-users] Help needed : reading data from two ttyUSB devices

[Eric S. Raymond]

Victor Klein <address@hidden>:
> I installed gpsd on a tp-link mr3020 router running an embedded linux
> provided by openwrt.org.
> 
> It runs fine, but reads data only from the first device.
> 
> I have a sirf-gps with 4800 baud and a second FTDI-USD-Serial-Converter
> delivering AIS-data with 38400 baud
> connected to the linux box.
> 
> I start the gpsd as a daemon with gpsd -G /dev/ttyUSB0 cause I want to read
> the data from another client.
> 
> My problem is as follows:
> 
> The gpsd reads the data from first device, both sirf-gps oder AIS run when
> plugged first and recognized on /dev/ttyUSB0
> I can telnet to the box, send a ?WATCH{"enable":true,"raw":1} 
> After some time ( about 20 second for the gps , about 3 minutes for the AIS,
> takes longer cause the gpsd has to recognise that data come with 38400 bps)
> valid nmea messages show up in the terminal.
> 
> 
> But the data of the second source which is bound to /dev/ttyUSB1 is not
> transfered.
> 
> The gpsd Version 2.6 ith was installed via the package-manager opkg
> 
> I studied the documentation but I did not find a hint how configure gpsd to
> work with data from the second device
> 
> If I start the gpsd with debug options like gpsd -N -n -G /dev/ttyUSB0 data
> is onlx read from the first box,
> I can confirm, that both a recognized and bound to ttyUSB0 and ttyUSB1
> 
> help appreciated

Try 

    gpsd -G /dev/ttyUSB0 /dev/ttyUSB1

I suspect the problem here is that gpsd never gets a notification from the 
hotplug sysyem about the second device (because it's already bound to 
/dev/ttyUSB1 when gpsd starts up) and so never sniffs at it.
-- 
                <a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>