I have a pi zero with USB GPS which keeps loosing position. It seems to be a problem with the USB but I've changed all of the hardware including the pi, SD card, GPS and power supply with exactly the same problem.
gpsd shows that it cannot access the USB device:
# service gpsd status
● gpsd.service - GPS (Global Positioning System) Daemon
Loaded: loaded (/lib/systemd/system/gpsd.service; disabled; vendor preset: enabled)
Active: active (running) since Wed 2020-07-29 22:12:12 BST; 4s ago
Process: 1413 ExecStart=/usr/sbin/gpsd $GPSD_OPTIONS $DEVICES (code=exited, status=0/SUCCESS)
Main PID: 1414 (gpsd)
Memory: 392.0K
CGroup: /system.slice/gpsd.service
└─1414 /usr/sbin/gpsd -n /dev/ttyACM0
Jul 29 22:12:11 raspberrypi systemd[1]: Starting GPS (Global Positioning System) Daemon...
Jul 29 22:12:12 raspberrypi systemd[1]: Started GPS (Global Positioning System) Daemon.
Jul 29 22:12:12 raspberrypi gpsd[1414]: gpsd:ERROR: SER: device open of /dev/ttyACM0 failed: No such device - retrying read-only
Jul 29 22:12:12 raspberrypi gpsd[1414]: gpsd:ERROR: SER: read-only device open of /dev/ttyACM0 failed: No such device
Jul 29 22:12:12 raspberrypi gpsd[1414]: gpsd:ERROR: initial GPS device /dev/ttyACM0 open failed
The output from lsusb is
$ lsusb
Bus 001 Device 009: ID 1546:01a8 U-Blox AG [u-blox 8]
Bus 001 Device 005: ID 05c6:6000 Qualcomm, Inc. Siemens SG75
Bus 001 Device 002: ID 0a05:7211 Unknown Manufacturer hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
The device looks OK:
$ ls -la /dev/ttyACM0
crw-rw---- 1 root dialout 166, 0 Jul 31 15:48 /dev/ttyACM0
There's nothing in syslog/kern.log/messages to say that the USB has lost connection.
Any ideas would be most appreciated.
Thanks, Tim
