GPS device problem

My GPS dongle is mounted and streaming NMES statements but on /dev/ttyACM0. The gpsd-mgr.log is complaining that it did not find the GPS dongle on /dev/ttyUSB*.

If I link /dev/ttyACM to /dev/ttyUSB0 will the system pick it up ok or should I make an entry in udev/rules.d for it specifically?

I don’t think there’s any harm in trying that, but I wonder why it picked it up as ttyACM instead of ttyUSB. Is it a USB dongle?

Yes it is a Ublox 7 based device. I just plug it into a USB socket on the RPi. It is working perfectly too.

Devices that implement a UART-over-USB are usually picked up as /dev/ttyUSB# devices. These devices often have FTDI FT232 or CH340 uart bridge chips in them. The UBLOX chip has a genuine USB interface and the drivers are already in Linux. They usually connect as /dev/ACM#.

I can reconfigure the NTP server to read from my GPS or I can create a UDEV rule to permanently create the expected device. The NTP server just reads the NMEA stream from the GPS so either should work - unless your application is reading the GPS directly.

1 Like

I would say try it. Like I said, I don’t see any harm in making the connection. I would love to hear the outcome as unfortunately I have no way of testing this myself.

Pending success I will ask Richard if he can create a script that enables this automatically, or possibly an option to enable manually from the web front end.

I will try a few things and, when solved, I will report my findings/solution on the forum.

1 Like