Serial device as input

[ymmengin]

Hello,

I'm trying to get data from a USB serial device on a RPi. It’s a QK-A021 USB AIS receiver dongle from Quark-elec.

I got a list of devices using:
$ AIS-catcher -l
AIS-catcher (build Dec 6 2025) v0.65-0-g096fdde2
(C) Copyright 2021-2025 jvde-github and other contributors
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Found 4 device(s):
0: RadarBox, ADS-B, SN: 00001090
1: Nooelec, NESDR SMArTee v5, SN: 00000162
2: Serial, USB Serial, SN: usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00
3: Serial, USB Serial, SN: usb-u-blox_AG_-www.u-blox.com_u-blox_7-_GPS_GNSS_Receiver-if00

The device I'm interested in is a QK-A021 USB AIS receiver. It's listed as # 2 Serial. So I added to my working config:
-e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00
I also tried: -e 38400 /dev/ttyACM1
This results in AIS-catcher giving an code=exited, status=255/EXCEPTION

My config is as follows:
-d 00000162
-e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00
-v 10
-M DT
-gr rtlagc on
-s 1536k
-p 0.5
-o 4
-N 8383 geojson on REALTIME on CDN /usr/share/aiscatcher/webassets
-N share_loc on
-t gpsd localhost 2947
-S 10111
-N FILE /usr/share/aiscatcher/stat.bin BACKUP 60
-N PLUGIN_DIR /usr/share/aiscatcher/my-plugins
-X
-N HISTORY 300

Any ideas? Thanks!

[jvde-github]

There must be some sort of error message why the device cannot be opened...

Can you stop the service for a moment sudo systemctl stop ais-catcher and try:

/usr/bin/AIS-catcher -e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00 -v

and see what the output is?

[ymmengin]

Thanks for your reply. I added the -v at the end. of the config string. No change:

-e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00 -v

pi@PUFFIN-RPi5-ROAMER:~ $ sudo systemctl stop aiscatcher
pi@PUFFIN-RPi5-ROAMER:~ $ sudo systemctl status aiscatcher
○ aiscatcher.service - AIS-catcher
Loaded: loaded (/lib/systemd/system/aiscatcher.service; enabled; preset: enabled)
Active: inactive (dead) (Result: exit-code) since Thu 2025-12-18 21:42:06 CET; 11s ago
Duration: 1.670s
Process: 2482905 ExecStart=/bin/bash /usr/share/aiscatcher/start-ais.sh (code=exited, status=255/EXCEPTION)
Main PID: 2482905 (code=exited, status=255/EXCEPTION)
CPU: 48ms

Dec 18 21:41:56 PUFFIN-RPi5-ROAMER systemd[1]: aiscatcher.service: Failed with result 'exit-code'.
Dec 18 21:42:06 PUFFIN-RPi5-ROAMER systemd[1]: Stopped aiscatcher.service - AIS-catcher.

pi@PUFFIN-RPi5-ROAMER:~ $ sudo systemctl status aiscatcher
● aiscatcher.service - AIS-catcher
Loaded: loaded (/lib/systemd/system/aiscatcher.service; enabled; preset: enabled)
Active: activating (auto-restart) (Result: exit-code) since Thu 2025-12-18 21:43:51 CET; 2s ago
Process: 2486328 ExecStart=/bin/bash /usr/share/aiscatcher/start-ais.sh (code=exited, status=255/EXCEPTION)
Main PID: 2486328 (code=exited, status=255/EXCEPTION)
CPU: 65ms

Dec 18 21:43:51 PUFFIN-RPi5-ROAMER systemd[1]: aiscatcher.service: Failed with result 'exit-code'.

[jvde-github]

Sorry, I mean can you run it from the command line after stopping the service and see what output you get. I think the command line command is:

/usr/local/bin/AIS-catcher -e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00 -v

[jvde-github]

Oh and thanks for testing and sharing btw!

[jvde-github]

if the above command does work, maybe start as user aiscat:

sudo -u aiscat /usr/local/bin/AIS-catcher -e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00

If that does not work, maybe you need to give permission to user aiscat to access this device:

 sudo usermod -a -G dialout aiscat

[jvde-github]

I suddenly realized you probably run the script from abcd5678 and not the project installation script, I think. This alternative script creates a user aiscat which might be the issue.

An alternative issue might be that this script gets confused by the - in the serial name. But let's see if the above resolves it first.

[ymmengin]

Thanks for your help. You nailed it. Permissions issue.

$ sudo -u aiscat /usr/local/bin/AIS-catcher -e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00
AIS-catcher (build Dec 17 2025) v0.66-0-gdaccafac
(C) Copyright 2021-2025 jvde-github and other contributors
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Failed to open serial port /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00 at baudrate 38400.
$ sudo usermod -a -G dialout aiscat
$ sudo -u aiscat /usr/local/bin/AIS-catcher -e 38400 /dev/serial/by-id/usb-STMicroelectronics_STM32_Virtual_COM_Port_6D8A54695551-if00
AIS-catcher (build Dec 17 2025) v0.66-0-gdaccafac
(C) Copyright 2021-2025 jvde-github and other contributors
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
!AIVDM,1,1,,A