Changes between Version 26 and Version 27 of gps

Timestamp:

06/30/2025 11:44:00 PM (4 hours ago)

Author:

Tim Harvey

Comment:

added gpsd details about baudrate

gps

@@ -408 +408 @@
 root@focal-venice:~# apt-get install gpsd gpsd-clients
 }}}
-  2. Configure gpsd via /etc/defaults/gpsd
+  1. Configure gpsd via /etc/defaults/gpsd
 {{{
 root@focal-venice:~# cat /etc/default/gpsd
@@ -427 +427 @@
 root@focal-venice:~# cat /etc/default/gpsd
 root@focal-venice:~# sed -i 's;DEVICES="";DEVICES="/dev/ttymxc0";' /etc/default/gpsd
-}}}
-   * replace the above with the proper GPS device for your system - see [#uart]
-  3. Restart the gpsd service
+root@focal-venice:~# sed -i 's;GPSD_OPTIONS="";GPSD_OPTIONS="-s 38400";' /etc/default/gpsd
+}}}
+   * replace the above with the proper GPS device and baudrate for the GPS on your board - see [#uart]
+  1. Restart the gpsd service
 {{{#!bash
 root@focal-venice:~# systemctl restart gpsd.socket
 }}}
-  4. Verify gpsd is listening:
+  1. Verify gpsd is listening:
 {{{#!bash
 root@focal-venice:~# netstat -a | grep gpsd
@@ -440 +441 @@
 unix  2      [ ACC ]     STREAM     LISTENING     23508    /run/gpsd.sock
 }}}
-  4. Verify gpsd is working using one of its client apps, for example cgps which is a simple terminal client:
+  1. Verify gpsd is working using one of its client apps, for example cgps which is a simple terminal client:
 {{{#!bash
 root@focal-venice:~# cgps
@@ -459 +460 @@
 gpsd:INFO: startup at 2021-10-08T21:30:00.000Z (1633728600)
 }}}
+ * gpsd will switch baudrates if it can't make sense of the data received however this can take several minutes for it to land on the proper baudrate depending upon how many times it has to change as the gpsd code will try the tty default baudrate first (which is usually 9600), then 4800, 9600, 19200, 38400, 57600, 115200, 230400, 460800, 921600 in that order. If for example the GPS default baudrate is 38400 that will be the 5th fallback which takes minutes. To address this you can either:
+  - add an 'stty -F /dev/ttymxc0 384000' (change for your GPS device and baudrate) to an ExecStartPre setting under the gpsd.service (ie 'sudo systemctl edit gpsd.service)
+  - add a '-s 384000' option to GPSD_OPTIONS as shown in he example above