Re: [gpsd-users] PPS Problem with U-blox NEO-7 GPS Under Debian 7.5 (Wheezy)

[Benedikt Kleinmeier]

Hi,

in the meantime, I talked to Gary E. Miller to narrow down the PPS problem. 
Even if we haven't solved the problem, I would like to transfer the discussion 
back to the mailing list so that everybody can follow it:

>> 2. No RS232 cable is used.
> 
> No deteremined yet.

The PC I use is called "ARTiS PC". It was designed by a German embedded systems 
specialist, called "Embedded Brains". From their manual:

    3.13. GPS Module
    Further the ARTiS PC is equipped with a NEO-7 GPS module from u-blox [6]. 
To get exact time
    informations a CPLD from Lattice is connect to the timepuls pin of the 
NEO-7. The CPLD is connected
    to the computer board using the LPC bus.

So, I assume that the PPS signal is provided on the LPC bus (Low Pin Count; a 
replacement for the old ISA bus to allow the usage of legacy devices). I.e. 
neither RS232 nor USB.

> Since you are supposed to create /var/run/chrony.ttyACM0, not gpsd, it 
> is hard to blame gpsd.

Okay. But since I use ntpd and not chrony, I'm not surprised that 
"/var/run/chrony.ttyACM0" is missing. I guess if I would use chrony, chrony 
would create that socket automatically (if it's configured correctly).

> Also, you have still not provided the initial info needed for any and all 
> debugging:
> 
> 1. what version of gpsd are you running.
> 2. what command line do you use to start gpsd 3. a link to your GPS doc.

1. gpsd: 3.6 (revision 3.6). "apt-get" reports package version 3.6-4+deb7u1.
2. /usr/sbin/gpsd -n -D 4 -F /var/run/gpsd.sock -P /var/run/gpsd.pid 
/dev/ttyACM0
    It is started automatically during boot by Debian's init.d mechanism.
3. Data sheet, protocol specification and hardware integration:
    - 
http://www.u-blox.com/images/downloads/Product_Docs/NEO-7_DataSheet_%28GPS.G7-HW-11004%29.pdf
    - 
http://www.u-blox.com/images/downloads/Product_Docs/u-blox7-V14_ReceiverDescriptionProtocolSpec_Public_%28GPS.G7-SW-12001%29.pdf
    - 
http://www.u-blox.com/images/downloads/Product_Docs/MAX7-NEO7_HardwareIntegrationManual_%28UBX-13003704%29.pdf

Thank you very much for your help. I highly appreciate it. :)

Have a nice day,
Benedikt