[gpsd-users] GPSD networking

[Deven Hickingbotham]

I'm trying to network two Raspberry Pis using gpsd 3.16-4.

The server Pi uses an Ultimate GPS Hat:

gpsd -N -n -b -G /dev/ttyAMA0

GPS commands executed on the server work fine.

On the client:

gpsd -N -D8 tcp://192.168.0.108:2947

but the connection to the server doesn't work as no GPS data is shown 
when executing cpgs.  I've also tried with gpsd:// without success, also 
with and without the port number.

Below is the debug output of the client.

Thanks,

Deven



Client debug output:

** start gpsd **

gpsd:INFO: launching (Version 3.16)
gpsd:IO: opening IPv4 socket
gpsd:SPIN: passivesock_af() -> 3
gpsd:IO: opening IPv6 socket
gpsd:SPIN: passivesock_af() -> 4
gpsd:INFO: listening on port gpsd
gpsd:PROG: NTP: shmat(688137,0,0) succeeded, segment 2
gpsd:PROG: NTP: shmat(720906,0,0) succeeded, segment 3
gpsd:PROG: NTP: shmat(753675,0,0) succeeded, segment 4
gpsd:PROG: NTP: shmat(786444,0,0) succeeded, segment 5
gpsd:PROG: NTP: shmat(819213,0,0) succeeded, segment 6
gpsd:PROG: NTP: shmat(851982,0,0) succeeded, segment 7
gpsd:PROG: successfully connected to the DBUS system bus
gpsd:PROG: shmget(0x47505344, 8928, 0666) for SHM export succeeded
gpsd:PROG: shmat() for SHM export succeeded, segment 884751
gpsd:INFO: stashing device tcp://192.168.0.108:2947 at slot 0
gpsd:INFO: running with effective group ID 1000
gpsd:INFO: running with effective user ID 1000
gpsd:INFO: startup at 2018-09-20T00:16:32.000Z (1537402592)

** now execute cpgs on client **

gpsd:SPIN: select() {3 4} -> { 4 } at 1537402599.610457 (errno 0)
gpsd:SPIN: client ::1 (0) connect on fd 6
gpsd:CLIENT: => client(0): 
{"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11}\x0d\x0a
gpsd:SPIN: select() {3 4 6} -> { 6 } at 1537402599.611619 (errno 0)
gpsd:PROG: checking client(0)
gpsd:CLIENT: <= client(0): ?WATCH={"enable":true,"json":true};\x0a
json: json_read_object() sees '{"enable":true,"json":true};
'
json: Target address for class (offset 0) is (nil)
json: Target address for enable (offset 0) is 0x9c290
json: Target address for scaled (offset 0) is 0x9c298
json: Target address for timing (offset 0) is 0x9c299
json: Target address for split24 (offset 0) is 0x9c29a
json: Target address for pps (offset 0) is 0x9c29b
json: Target address for device (offset 0) is 0x9c2a0
json: Target address for remote (offset 0) is 0x9c320
json: Target address for pps (offset 0) is 0x7e9b88df
json: JSON parse of '{"enable":true,"json":true};
' begins.
json: State init          , looking at '{' (0x7e9bd053)
json: State await_attr    , looking at '"' (0x7e9bd054)
json: State in_attr       , looking at 'e' (0x7e9bd055)
json: State in_attr       , looking at 'n' (0x7e9bd056)
json: State in_attr       , looking at 'a' (0x7e9bd057)
json: State in_attr       , looking at 'b' (0x7e9bd058)
json: State in_attr       , looking at 'l' (0x7e9bd059)
json: State in_attr       , looking at 'e' (0x7e9bd05a)
json: State in_attr       , looking at '"' (0x7e9bd05b)
json: Collected attribute name enable
json: Checking against class
json: Checking against enable
json: State await_value   , looking at ':' (0x7e9bd05c)
json: State await_value   , looking at 't' (0x7e9bd05d)
json: State in_val_token  , looking at 'r' (0x7e9bd05e)
json: State in_val_token  , looking at 'u' (0x7e9bd05f)
json: State in_val_token  , looking at 'e' (0x7e9bd060)
json: State in_val_token  , looking at ',' (0x7e9bd061)
json: Collected token value true.
json: State post_val      , looking at ',' (0x7e9bd061)
json: Target address for enable (offset 0) is 0x9c290
json: State await_attr    , looking at '"' (0x7e9bd062)
json: State in_attr       , looking at 'j' (0x7e9bd063)
json: State in_attr       , looking at 's' (0x7e9bd064)
json: State in_attr       , looking at 'o' (0x7e9bd065)
json: State in_attr       , looking at 'n' (0x7e9bd066)
json: State in_attr       , looking at '"' (0x7e9bd067)
json: Collected attribute name json
json: Checking against class
json: Checking against enable
json: Checking against json
json: State await_value   , looking at ':' (0x7e9bd068)
json: State await_value   , looking at 't' (0x7e9bd069)
json: State in_val_token  , looking at 'r' (0x7e9bd06a)
json: State in_val_token  , looking at 'u' (0x7e9bd06b)
json: State in_val_token  , looking at 'e' (0x7e9bd06c)
json: State in_val_token  , looking at '}' (0x7e9bd06d)
json: Collected token value true.
json: State post_val      , looking at '}' (0x7e9bd06d)
json: Target address for json (offset 0) is 0x9c291
json: JSON parse ends.
gpsd:PROG: no /etc/gpsd/device-hook present, skipped running ACTIVATE hook
gpsd:INFO: opening TCP feed at 192.168.0.108, port 2947.
gpsd:SPIN: TCP device opened on fd 7
gpsd:INFO: gpsd_activate(2): activated GPS (fd 7)
gpsd:RAW: flagging descriptor 7 in assign_channel()
gpsd:CLIENT: => client(0): 
{"class":"DEVICES","devices":[{"class":"DEVICE","path":"tcp://192.168.0.108:2947","activated":"2018-09-20T00:16:39.615Z"}]}\x0d\x0a{"class":"WATCH","enable":true,"json":true,"nmea":false,"raw":0,"scaled":false,"timing":false,"split24":false,"pps":false}\x0d\x0a
gpsd:SPIN: select() {3 4 6 7} -> { 7 } at 1537402599.616617 (errno 0)
gpsd:SPIN: packet_get() fd 7 -> 86 (0)
gpsd:RAW: packet sniff on tcp://192.168.0.108:2947 finds type 18
gpsd:PROG: switching to match packet type 18: 
{"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11}
gpsd:PROG: switch_driver(JSON slave driver) called...
gpsd:PROG: selecting JSON slave driver driver...
gpsd:INFO: tcp://192.168.0.108:2947 identified as type JSON slave 
driver, 0 sec @ 0bps
gpsd:RAW: raw packet of type 18, 
84:{"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11}
gpsd:IO: <= GPS: 
{"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11}
gpsd:PROG: JSON, passing through 
{"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11,"remote":"tcp://192.168.0.108:2947"}
gpsd:DATA: packet type 18 from tcp://192.168.0.108:2947 with 
{ONLINE|PACKET|DRIVER|PASSTHROUGH}
gpsd:PROG: device 0 (fd=7, path tcp://192.168.0.108:2947) already active.
gpsd:CLIENT: => client(0): 
{"class":"DEVICE","path":"tcp://192.168.0.108:2947","driver":"JSON slave 
driver","activated":"2018-09-20T00:16:39.617Z"}\x0d\x0a
gpsd:CLIENT: => client(0): 
{"class":"VERSION","release":"3.16","rev":"3.16-4","proto_major":3,"proto_minor":11,"remote":"tcp://192.168.0.108:2947"}\x0d\x0a
gpsd:SPIN: packet_get() fd 7 -> 0 (11)
gpsd:RAW: tcp://192.168.0.108:2947 is known to be JSON slave driver

** now terminate cgps on client **

gpsd:SPIN: select() {3 4 6 7} -> { 6 } at 1537403061.316695 (errno 0)
gpsd:PROG: checking client(0)
gpsd:SPIN: close(6) in detach_client()
gpsd:INFO: detaching ::1 (sub 0, fd 6) in detach_client
gpsd:PROG: device 0 (fd 7) released