GPS Data from Qualcomm Modem

[mukulele]

I am using a LTE CAT-M modem to receive GPS NMEA data.
The command (e.g. qmicli -p -d /dev/cdc-wdm0 --loc-follow-nmea --client-cid=1)
generates a stream of NMEA0183 sentences like this:

$GLGSV,2,1,08,74,66,078,27,66,16,334,14,73,22,109,40,75,46,313,26,171
$GLGSV,2,2,08,65,16,281,17,84,62,106,25,85,23,178,24,83,22,028,,174
$GPGSV,3,1,10,06,17,037,29,11,32,070,33,12,48,080,38,24,,,17,152
$GPGSV,3,2,10,25,81,012,26,28,41,302,18,29,51,209,30,32,25,246,27,16E
$GPGSV,3,3,10,31,16,310,,49,,,33,1*5F

How can I "pipe" this terminal output into Signal-K?

[tkurki]

There's something called "execute provider" that spawns a command and uses its stdout as the input to a SK Server "piped provider", a sequence of processing steps. You'll need to configure it by manually editing your settings.json and splice together these elements:

• https://github.com/SignalK/signalk-server/blob/master/settings/commandline-provider-settings.json#L11-L17
• https://github.com/SignalK/signalk-server/blob/master/settings/volare-file-settings.json#L34-L39

Naturally use your command instead of the echo example and no need for the sentenceEvent option (unrelated, just happens to be in the example file).

...but the actual data that you included is not valid, for one thing only the last sentence has checksum. You may get away with it by configuring the sk connection to ignore checksums.

[mukulele]

Thanks for your reply. My post below was sent before I got your answer. Let me check...

[mukulele]

If I understand correctly:

step1: https://github.com/SignalK/signalk-server/blob/master/settings/commandline-provider-settings.json#L11-L17
executes commands to setup the data stream.

If so, my alternative solution:
"qmicli -p -d /dev/cdc-wdm0 --loc-follow-nmea --client-cid=1 > /dev/udp/127.0.0.1/2947 &" will stream via udp to port 2947
should replace your step 1.

step 2: https://github.com/SignalK/signalk-server/blob/master/settings/volare-file-settings.json#L34-L39
will setup the "consumer" for the datastream.

My setting.json currently looks like this:

"pipedProviders": [
{
"pipeElements": [
{
"type": "providers/simple",
"options": {
"logging": true,
"type": "NMEA0183",
"subOptions": {
"validateChecksum": false,
"type": "udp",
"port": "2947",
"suppress0183event": false
}
}
}
],
"id": "GPS_QMI",
"enabled": true
}
],

This does not produce connection activity. What am I missing?
Thxs for your kind support.

[tkurki]

No idea. Try the execute provider route, it has the added benefit that you don’t need the extra process to feed data, as the server process spawns the command.

[mukulele]

Got it. I missed (to mention) the point that my Signal-K is running in docker.
After forwarding the port (Port: 2947:2947/udp) to the container, I can now receive the NMEA 0183 sentences.

[mukulele]

"qmicli -p -d /dev/cdc-wdm0 --loc-follow-nmea --client-cid=1 > /dev/udp/127.0.0.1/2947 &" will stream via udp to port 2947.
("&" sends the process to the background)
I can receive the stream via nc -ulp 2947 in another terminal , but not (yet) in Signal K.

I have setup a new data connection in Signal-K:
Data Type: Signal K
Signal K Source: udp
Port 2947
self handling: Map remote self to self

Unfortunately this setup does not generate any Connection activity on the dashboard.

The Signal-K log output on "signalk-server:events:NO_EMITTER_ID:serverevent" shows:
Jan 12 15:51:36 2024-01-12T15:51:36.290Z signalk-server:events:NO_EMITTER_ID:serverevent { type: 'SERVERSTATISTICS', from: 'signalk-server', data: { deltaRate: 0, numberOfAvailablePaths: 8, wsClients: 1, providerStatistics: { defaults: [ProviderStats], GPS_QMI: [Object] }, uptime: 86.677513268 } }
Jan 12 15:51:41 2024-01-12T15:51:41.291Z signalk-server:events:NO_EMITTER_ID:serverevent { type: 'PROVIDERSTATUS', from: 'signalk-server', data: [ { type: 'status', id: 'course-provider', statusType: 'plugin', timeStamp: '1/12/2024, 3:50:17 PM', message: 'Started' }, { type: 'status', id: 'freeboard-sk', statusType: 'plugin', timeStamp: '1/12/2024, 3:50:17 PM', message: 'Started' }, { type: 'status', id: 'resources-provider', statusType: 'plugin', timeStamp: '1/12/2024, 3:50:18 PM', message: 'Providing: routes,waypoints,notes,regions' }, { type: 'error', id: 'signalk-websocket-provider', statusType: 'provider', timeStamp: '1/12/2024, 3:50:18 PM', message: 'Failed to start: undefined' } ] }

Any hints how to move forward?
Best regards
Christian

[tkurki]

Your data is NMEA0183, setting Data Type to Signal K you are expecting Signal K JSON.

[tkurki]

Did you activate debug key signalk-server:events:NO_EMITTER_ID:serverevent or why are you seeing that output? It is totally unrelated.

[mukulele]

I was just checking for any output related to that data connection.