# VOXL 2 Connecting an External Flight Controller Problem

Source: https://forum.modalai.com/topic/4849/voxl-2-connecting-an-external-flight-controller-problem
Category: VOXL 2 and VOXL 2 Mini (https://forum.modalai.com/category/26/voxl-2-and-voxl-2-mini)
Tags: voxl-2
Posted: 2025-11-01 08:14:59 UTC by ravi
Replies: 13 · Views: 1239

## ravi · 2025-11-01 08:14:59 UTC

Hi @Moderator,

I am using VOXL2 and FCv2.
and following [VOXL 2 Connecting an External Flight Controller](https://docs.modalai.com/voxl2-external-flight-controller/)
Document for FCv2 and VOXl2 connection and configuration.

## Setup
Both FCv2 and VOXl2 are connected to the PC.
And J1 of FCv2 and J18 of VOXL2 is connected for MAVLINK UART connection.
![Conenction details](![b6c6849c-e75f-468c-9c1c-05be34ff146e-image.png](https://forum.modalai.com/assets/uploads/files/1761983487076-b6c6849c-e75f-468c-9c1c-05be34ff146e-image.png) image url)

## SW configuration

-  voxl-mavlink-server config file. (/etc/modalai/voxl-mavlink-server.conf)
```
{
        "primary_static_gcs_ip":        "",
        "secondary_static_gcs_ip":      "",
        "onboard_port_to_autopilot":    14556,
        "onboard_port_from_autopilot":  14557,
        "gcs_port_to_autopilot":        14558,
        "gcs_port_from_autopilot":      14559,
        "en_external_uart_ap":  true,
        "autopilot_uart_bus":   12,
        "autopilot_uart_baudrate":      57600,
        "autopilot_mission_delay_start":        -1,
        "autopilot_mission_delay_sound":        false,
        "autopilot_mission_force_restart":      10,
        "autopilot_mission_notif_dur":  0.1,
        "en_external_ap_timesync":      1,
        "en_external_ap_heartbeat":     1,
        "udp_mtu":      0,
        "gcs_timeout_s":        4.5
}
"/etc/modalai/voxl-mavlink-server.conf" 66L, 3249C written
```
- voxl-inspect-services
```
voxl2:/$ voxl-inspect-services
Scanning services...

 Service Name             |  Enabled  |   Running   |  CPU Usage
───────────────────────────────────────────────────────────────────
 docker-autorun           | Disabled  | Not Running |
 modallink-relink         | Disabled  | Not Running |
 voxl-camera-server       |  Enabled  | Not Running |
 voxl-cpu-monitor         | Disabled  | Not Running |
 voxl-dfs-server          | Disabled  | Not Running |
 voxl-elrs-startup        | Disabled  | Not Running |
 voxl-feature-tracker     | Disabled  | Not Running |
 voxl-flow-server         | Disabled  | Not Running |
 voxl-iim-server          | Disabled  | Not Running |
 voxl-imu-server          | Disabled  | Not Running |
 voxl-io-server           | Disabled  | Not Running |
 voxl-lepton-server       | Disabled  | Not Running |
 voxl-lepton-tracker      | Disabled  | Not Running |
 voxl-logger              | Disabled  | Not Running |
 voxl-mavcam-manager      |  Enabled  |   Running   |     0.0%
 voxl-mavlink-server      |  Enabled  |   Running   |     0.0%
 voxl-mini-tof-server     | Disabled  | Not Running |
 voxl-modem               |  Enabled  |   Running   |     0.0%
 voxl-open-vins-server    | Disabled  | Not Running |
 voxl-osd                 | Disabled  | Not Running |
 voxl-portal              |  Enabled  |   Running   |     0.0%
 voxl-px4-imu-server      | Disabled  | Not Running |
 voxl-px4                 | Disabled  | Not Running |
 voxl-qvio-server         | Disabled  | Not Running |
 voxl-rangefinder-server  | Disabled  | Not Running |
 voxl-remote-id           | Disabled  | Not Running |
 voxl-rpx-sever           | Disabled  | Not Running |
 voxl-seek-server         | Disabled  | Not Running |
 voxl-softap              | Disabled  | Not Running |
 voxl-state-estimator     | Disabled  | Not Running |
 voxl-static-ip           | Disabled  | Not Running |
 voxl-stitcher            | Disabled  | Not Running |
 voxl-streamer            |  Enabled  |   Running   |     0.0%
 voxl-tag-detector        | Disabled  | Not Running |
 voxl-tflite-server       | Disabled  | Not Running |
 voxl-time-sync           | Disabled  | Not Running |
 voxl-uvc-server          | Disabled  | Not Running |
 voxl-vision-hub          | Disabled  | Not Running |
 voxl-vrx                 | Disabled  | Not Running |
 voxl-vtx                 | Disabled  | Not Running |
 voxl-wait-for-fs         |  Enabled  |  Completed  |
```

- voxl-mavlink-server status
```
voxl2:/$ systemctl status voxl-mavlink-server
● voxl-mavlink-server.service - voxl-mavlink-server
   Loaded: loaded (/usr/bin/voxl-mavlink-server; enabled; vendor preset: enabled)
   Active: active (running) since Thu 2025-05-01 17:59:43 UTC; 6min ago
  Process: 1675 ExecStartPre=/bin/sleep 2 (code=exited, status=0/SUCCESS)
 Main PID: 1968 (voxl-mavlink-se)
    Tasks: 30 (limit: 4915)
   CGroup: /system.slice/voxl-mavlink-server.service
           └─1968 /usr/bin/voxl-mavlink-server

May 01 17:59:43 m0054 voxl-mavlink-server[1968]: autopilot_mission_delay_sound:      0
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: autopilot_mission_force_restart:      10
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: autopilot_mission_notif_dur:      0.10
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: udp_mtu:                      0
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: gcs_timeout_s                 4.50
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: en_external_ap_timesync:      1
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: en_external_ap_heartbeat:     1
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: =================================================================
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: Sending library name request: libslpi_qrb5165_io.so
May 01 17:59:43 m0054 voxl-mavlink-server[1968]: Sending initialization request
```

- systemctl restart voxl-mavlink-server
```
May 01 19:22:02 m0054 voxl-mavlink-server[16506]: received SIGTERM
May 01 19:22:02 m0054 systemd[1]: Stopping voxl-mavlink-server...
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Successfully opened bus 12 at baudrate 921600
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: starting qrb5165 external AP receive thread
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Not connecting to primary gcs ip:
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Not connecting to secondary gcs ip:
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Init complete, entering main loop
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Starting shutdown sequence
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Stopping autopilot io module
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: exiting read thread
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: qrb5165 external ap interface stopped
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Stopping gcs io module
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: exiting gcs udp listener thread
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: udp gcs io stopped
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Stopping pipe io module
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: closing remaining client pipes
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: closing remaining server pipes
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: Removing PID file
May 01 19:22:03 m0054 voxl-mavlink-server[16506]: exiting
May 01 19:22:03 m0054 systemd[1]: Stopped voxl-mavlink-server.
May 01 19:22:03 m0054 systemd[1]: Starting voxl-mavlink-server...
May 01 19:22:05 m0054 systemd[1]: Started voxl-mavlink-server.
May 01 19:22:05 m0054 voxl-mavlink-server[17426]: loading our own config file
May 01 19:22:05 m0054 voxl-mavlink-server[17426]: =================================================================
May 01 19:22:05 m0054 voxl-mavlink-server[17426]: Parameters as loaded from config file:
```
# Problem
- Currently using SDK 1.4
- I disabled the voxl-px4 service on VOXL2.
- Connected FCv2 TELEM1 port J1 with J18 port of VOXL2.
- Using baudrate 57600 on both
- Now for J18 port on VOXL2 using “autopilot_uart_bus”: 12 (SLPI_QUP2_UART/QUP2) in configuration.
- Now, it seems DSP libslpi is getting hung/stuck and not responding, as shown in voxl-mavlink-server status. The last line is "Sending initialization request". Then there is no log form mavlink-server.
- Now, if I restart the MAVLink server. after stopping the interrupt. port seems open and then closes. as above log.

Is it an issue with SLPI, or is the DSP UART port not usable for MAVLINK?
Help me debug and provide a resolution.

Thanks.
Ravi

## Reply by ravi · 2025-11-01 08:22:55 UTC

@ravi 

Find the VOXL2 app versions.
```
voxl2:/$ voxl-version
────────────────────────────────────────────────────────────────────────────────
system-image: 1.8.02-M0054-14.1a-perf
kernel:       #1 SMP PREEMPT Mon Nov 11 22:08:01 UTC 2024 4.19.125
────────────────────────────────────────────────────────────────────────────────
hw platform:  M0054
mach.var:     1.0.0
SKU:          MRB-D0006-4-V1-C11-T1-M23-X0
────────────────────────────────────────────────────────────────────────────────
voxl-suite:   1.4.4-202504302200
────────────────────────────────────────────────────────────────────────────────
Packages:
Repo:  http://voxl-packages.modalai.com/ qrb5165 dev
Last Updated: 2025-05-01 18:00:20
List:
kernel-module-voxl-fsync-mod-4.19.125     1.0-r0
kernel-module-voxl-gpio-mod-4.19.125      1.0-r0
kernel-module-voxl-platform-mod-4.19.125  1.0-r0
libfc-sensor                              1.0.7-202503131014
libmodal-cv                               0.5.17-202504301813
libmodal-exposure                         0.1.4-202504301817
libmodal-journal                          0.2.4-202504250956
libmodal-json                             0.4.6-202504301809
libmodal-pipe                             2.13.0-202504211020
libqrb5165-io                             0.4.9-202504291621
libvoxl-cci-direct                        0.3.1-202504301829
libvoxl-cutils                            0.1.4-202504301826
modalai-slpi                              1.1.20-202504131441
mv-voxl                                   0.1-r0
qrb5165-bind                              0.1-r0
qrb5165-dfs-server                        0.2.0-202309221318
qrb5165-imu-server                        1.2.0-202504241319
qrb5165-mini-tof-server                   0.2.2-202504291141
qrb5165-rangefinder-server                0.1.5-202502211754
qrb5165-slpi-test-sig                     01-r0
qrb5165-system-tweaks                     0.3.5-202503241242
qrb5165-tflite                            2.8.0-2-202210071637
voxl-benchmark-vio                        0.5.7-202504041555
voxl-bind-spektrum                        0.1.1-202403271220
voxl-camera-calibration                   0.5.9-202411191414
voxl-camera-server                        2.1.2-202504281425
voxl-capture                              0.0.1-202206110121
voxl-ceres-solver                         2:1.14.0-10-202504291324
voxl-configurator                         1.0.1-202504301741
voxl-cpu-monitor                          0.5.3-202504231157
voxl-cross-template                       0.0.1-202504171512
voxl-docker-support                       1.3.1-202404041529
voxl-elrs                                 0.4.4-202504041253
voxl-esc                                  1.5.2-202504292017
voxl-feature-tracker                      0.5.2-202412171357
voxl-flow-server                          0.3.6-202403180603
voxl-fsync-mod                            1.0-r0
voxl-gphoto2-server                       0.0.10-202210072352
voxl-gpio-mod                             1.0-r0
voxl-iim-server                           0.0.3-202503210929
voxl-io-server                            0.0.5-202502191136
voxl-joystick-server                      0.0.1-202504291738
voxl-jpeg-turbo                           2.1.3-7-202504301743
voxl-lepton-server                        1.3.3-202412171302
voxl-lepton-tracker                       0.0.4-202412190958
voxl-libgphoto2                           0.0.4-202204111958
voxl-libuvc                               1.0.7-202210072357
voxl-logger                               0.5.3-202504141224
voxl-mavcam-manager                       0.5.8-202504080850
voxl-mavlink                              0.1.5-202504301802
voxl-mavlink-server                       1.4.7-202504291641
voxl-modem                                1.1.6-202504301834
voxl-mongoose                             7.7.0-2-202504301848
voxl-mpa-to-ros                           0.3.9-202407091506
voxl-mpa-tools                            1.3.8-202504221446
voxl-open-vins                            0.4.18-202504301757
voxl-open-vins-server                     0.3.10-202504071452
voxl-opencv                               4.5.5-3-202504301748
voxl-osd                                  0.1.6-202504241636
voxl-platform-mod                         1.0-r0
voxl-portal                               0.7.10-202504240926
voxl-px4                                  1.14.0-2.0.104-202504231041
voxl-px4-imu-server                       0.1.2-202205131833
voxl-px4-params                           0.7.0-202504301738
voxl-qvio-server                          1.1.1-202411151825
voxl-remote-id                            0.0.9-202309191605
voxl-reset-slpi                           0.0.1-202405130827
voxl-rpx-server                           0.0.1-202409271312
voxl-rtp                                  0.0.1-202206101543
voxl-state-estimator                      0.0.5-202504181708
voxl-stitcher                             0.0.2-202206161634
voxl-streamer                             0.7.5-202412021550
voxl-suite                                1.4.4-202504302200
voxl-tag-detector                         0.0.4-202206302112
voxl-tflite-server                        0.4.1-202504301555
voxl-utils                                1.4.7-202504301851
voxl-uvc-server                           0.1.7-202405141018
voxl-vision-hub                           1.8.21-202504291456
voxl-vtx                                  1.3.13-202504291344
voxl-wavemux                              0.0.1-202503181201
voxl2-io                                  0.0.3-202405011635
voxl2-system-image                        1.8.02-r0
voxl2-wlan                                1.0-r0
────────────────────────────────────────────────────────────────────────────────
voxl2:/$
```

## Reply by Eric Katzfey (ModalAI staff) · 2025-11-01 17:28:30 UTC (in reply to ravi)

@ravi Can you stop the system service for voxl-mavlink-server (e.g. systemctl stop voxl-mavlink-server) and run it from the command line instead with the -z option to see all message traffic? You should see something like this: 
```
voxl2:/$ voxl-mavlink-server -z
Enabling UDP to slpi recv debugging
Enabling qrb5165 external AP recv debugging
Enabling UDP to slpi send debugging
Enabling qrb5165 external AP send debugging
Enabling UDP GCS recv debugging
Enabling UDP GCS send debugging
loading our own config file
=================================================================
Parameters as loaded from config file:
primary_static_gcs_ip:        192.168.0.131
secondary_static_gcs_ip:      192.168.8.11
onboard_port_to_autopilot:    14556
onboard_port_from_autopilot:  14557
gcs_port_to_autopilot:        14558
gcs_port_from_autopilot:      14559
en_external_uart_ap:          1
autopilot_uart_bus:           12
autopilot_uart_baudrate:      57600
autopilot_mission_delay_start:      -1
autopilot_mission_delay_sound:      0
autopilot_mission_force_restart:      0
autopilot_mission_notif_dur:      0.10
udp_mtu:                      0
gcs_timeout_s                 4.50
en_external_ap_timesync:      1
en_external_ap_heartbeat:     1
=================================================================
Sending library name request: libslpi_qrb5165_io.so
Sending initialization request
Successfully opened bus 12 at baudrate 57600
starting qrb5165 external AP receive thread
Adding primary GCS IP address from conf file to list: 192.168.0.131
Added new UDP connection to 192.168.0.131
Adding secondary manual gcs IP address to udp connection list: 192.168.8.11
Added new UDP connection to 192.168.8.11
Init complete, entering main loop
to AP msg ID:     0 sysid:  1   to bus: 12
RECV  msg ID:    70 sysid:255 from bus: 12
```

## Reply by ravi · 2025-11-03 16:38:49 UTC (in reply to Eric Katzfey)

@Eric-Katzfey 
For testing, I changed the UART port to 2 and then change to port 12.
stopped service and ran "voxl-mavlink-server -z"
and got the following errors.
```
![68d1045c-eaa7-46ee-b0de-b313bee851cb-1000019409.jpeg](https://forum.modalai.com/assets/uploads/files/1762187345269-68d1045c-eaa7-46ee-b0de-b313bee851cb-1000019409.jpeg) code_text
```

Then rebooted the VOXl2 and tried again, and got this log. But no MAVLink connection with FCv2. using J1 of FCv2 to connect  with J18 of VOXL2.
```
voxl2:/$ voxl-mavlink-server -z
Enabling UDP to slpi recv debugging
Enabling qrb5165 external AP recv debugging
Enabling UDP to slpi send debugging
Enabling qrb5165 external AP send debugging
Enabling UDP GCS recv debugging
Enabling UDP GCS send debugging
loading our own config file
=================================================================
Parameters as loaded from config file:
primary_static_gcs_ip:
secondary_static_gcs_ip:
onboard_port_to_autopilot:    14556
onboard_port_from_autopilot:  14557
gcs_port_to_autopilot:        14558
gcs_port_from_autopilot:      14559
en_external_uart_ap:          1
autopilot_uart_bus:           12
autopilot_uart_baudrate:      57600
autopilot_mission_delay_start:      -1
autopilot_mission_delay_sound:      0
autopilot_mission_force_restart:      0
autopilot_mission_notif_dur:      0.10
udp_mtu:                      500
gcs_timeout_s                 4.50
en_external_ap_timesync:      1
en_external_ap_heartbeat:     1
=================================================================
Sending library name request: libslpi_qrb5165_io.so
Sending initialization request
Successfully opened bus 12 at baudrate 57600
starting qrb5165 external AP receive thread
Not connecting to primary gcs ip:
Not connecting to secondary gcs ip:
Init complete, entering main loop
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
onboard  pipe  ID: 330 compid: 197
```

Check by heartbeat check. But no ap heartbeat.
```
voxl2:~/old_backup/etc-modalai/modalai$ voxl-inspect-mavlink mavlink_ap_heartbeat
waiting for pipe to connect
```

## Reply by ravi · 2025-11-03 16:43:50 UTC (in reply to ravi)

@Eric-Katzfey 

Also, seeing the following error messages pointing flight controller.
```
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Connection error: connection reset
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
Got response cb 0
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
Got response cb 0
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got flight controller event
Received standard error event SNS_STD_ERROR_NOT_SUPPORTED
Got response cb 0
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID:  84 compid: 197
to AP msg ID:    84 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 331 compid: 197
to AP msg ID:   331 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
Got response cb 0
onboard  pipe  ID: 330 compid: 197
to AP msg ID:   330 sysid:  1   to bus: 12
Sending topic message
--- msg_id: 1033
--- topic name: uart_data
```

## Reply by ravi · 2025-11-03 17:35:48 UTC (in reply to ravi)

@ravi 

mavlink-server status issue seems random.

I stopped the service and changed the baud rate, and ran app from the terminal "voxl-mavlink-server"

Seems MAVLink connection established. and getting an AP heart rate at 0.3Hz.

Then I tried the same with mavlink service.
I terminated it running process for the mavlik-server.
They started the MAVLink service. and checked status and not starting.

```
voxl2:/$ systemctl start voxl-mavlink-server
voxl2:/$ systemctl status voxl-mavlink-server
● voxl-mavlink-server.service - voxl-mavlink-server
   Loaded: loaded (/usr/bin/voxl-mavlink-server; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2023-03-02 13:29:47 UTC; 3s ago
  Process: 11260 ExecStart=/usr/bin/voxl-mavlink-server (code=exited, status=255)
  Process: 11253 ExecStartPre=/bin/sleep 2 (code=exited, status=0/SUCCESS)
 Main PID: 11260 (code=exited, status=255)

Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: ERROR: Unable to configure bus 12 (baudrate 460800) with voxl_io
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: Stopping autopilot io module
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: Stopping gcs io module
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: Stopping pipe io module
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: closing remaining client pipes
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: closing remaining server pipes
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: Removing PID file
Mar 02 13:29:47 m0054 voxl-mavlink-server[11260]: exiting
Mar 02 13:29:47 m0054 systemd[1]: voxl-mavlink-server.service: Main process exited, code=exited, status=255/n/a
Mar 02 13:29:47 m0054 systemd[1]: voxl-mavlink-server.service: Failed with result 'exit-code'.
voxl2:/$ systemctl start voxl-mavlink-server
```

Then tried from the terminal again, getting the error as below.
```
voxl2:/$ voxl-mavlink-server
loading our own config file
=================================================================
Parameters as loaded from config file:
primary_static_gcs_ip:
secondary_static_gcs_ip:
onboard_port_to_autopilot:    14556
onboard_port_from_autopilot:  14557
gcs_port_to_autopilot:        14558
gcs_port_from_autopilot:      14559
en_external_uart_ap:          1
autopilot_uart_bus:           12
autopilot_uart_baudrate:      460800
autopilot_mission_delay_start:      -1
autopilot_mission_delay_sound:      0
autopilot_mission_force_restart:      0
autopilot_mission_notif_dur:      0.10
udp_mtu:                      500
gcs_timeout_s                 4.50
en_external_ap_timesync:      1
en_external_ap_heartbeat:     1
=================================================================
Couldn't locate SUID for flight_controller
Failed to detect flight controller sensor
ERROR:   fc_sensor_initialize failed
ERROR:   Failed to initialize slpi
ERROR:   Encountered error while initializing bus 12
ERROR: Unable to configure bus 12 (baudrate 460800) with voxl_io
Stopping autopilot io module
Stopping gcs io module
Stopping pipe io module
closing remaining client pipes
closing remaining server pipes
Removing PID file
exiting
voxl2:/$ voxl-mavlink-server -z
Enabling UDP to slpi recv debugging
Enabling qrb5165 external AP recv debugging
Enabling UDP to slpi send debugging
Enabling qrb5165 external AP send debugging
Enabling UDP GCS recv debugging
Enabling UDP GCS send debugging
loading our own config file
=================================================================
Parameters as loaded from config file:
primary_static_gcs_ip:
secondary_static_gcs_ip:
onboard_port_to_autopilot:    14556
onboard_port_from_autopilot:  14557
gcs_port_to_autopilot:        14558
gcs_port_from_autopilot:      14559
en_external_uart_ap:          1
autopilot_uart_bus:           12
autopilot_uart_baudrate:      460800
autopilot_mission_delay_start:      -1
autopilot_mission_delay_sound:      0
autopilot_mission_force_restart:      0
autopilot_mission_notif_dur:      0.10
udp_mtu:                      500
gcs_timeout_s                 4.50
en_external_ap_timesync:      1
en_external_ap_heartbeat:     1
=================================================================
Couldn't locate SUID for flight_controller
Failed to detect flight controller sensor
ERROR:   fc_sensor_initialize failed
ERROR:   Failed to initialize slpi
ERROR:   Encountered error while initializing bus 12
ERROR: Unable to configure bus 12 (baudrate 460800) with voxl_io
Stopping autopilot io module
Stopping gcs io module
Stopping pipe io module
closing remaining client pipes
closing remaining server pipes
Removing PID file
exiting
voxl2:/$
```

## Reply by ravi · 2025-11-03 19:42:20 UTC (in reply to ravi)

@Eric-Katzfey 

I am testing with J18(VOXl2) and J1(TELEM1) port.
Seems SLPI is throwing a lot of errors in demsg.
and @115200 buadrate. 
- MAVLink connections are getting lost in a few minutes.
and getting rx loss of 124% on FCv2 QGC.

Can you let me know if the J18 DSP port is buggy or how to fix these errors?
After a few minutes or a few restarts of VOXl-mavlink-server. it stops working and shows an error and exits
```
Couldn't locate SUID for flight_controller
Failed to detect flight controller sensor
ERROR:   fc_sensor_initialize failed
ERROR:   Failed to initialize slpi
ERROR:   Encountered error while initializing bus 12
ERROR: Unable to configure bus 12 (baudrate 115200) with voxl_io
Stopping autopilot io module
Stopping gcs io module
Stopping pipe io module
closing remaining client pipes
closing remaining server pipes
Removing PID file
exiting
```

====> dmesg log while voxl-mavlink-server running stopped working and throwing an error when starting
```
[  460.730018] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  460.730717] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  460.730901] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  460.790600] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  460.853124] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  460.853154] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  460.860922] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  460.860928] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  460.861499] 1118855912:Entered
[  460.861942] 1118855912:SMD QRTR driver probed
[  460.862983] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  460.866169] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  460.866208] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  460.874694] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  462.106273] Fatal error on slpi!
[  462.106348] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  462.106375] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  462.108414] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  462.108416] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  462.120395] rpmh_rsc_send_data: 17 callbacks suppressed
[  462.120396] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  462.120423] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  462.121677] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  462.121691] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  462.122027] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  462.122151] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  462.122757] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  462.122886] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  462.178193] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  462.240639] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  462.240671] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  462.240789] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  462.247665] 1118855912:Entered
[  462.248151] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  462.248158] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  462.249366] 1118855912:SMD QRTR driver probed
[  462.252554] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  462.254897] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  462.254962] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  462.261500] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  463.481618] Fatal error on slpi!
[  463.481694] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  463.481720] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  463.483312] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  463.483315] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  463.495481] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.495494] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.495505] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.495516] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.495528] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.495539] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.495551] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  463.498539] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  463.498548] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  463.498944] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  463.499294] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  463.499834] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  463.499987] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  463.558705] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  463.619354] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  463.619389] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  463.626313] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  463.626319] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  463.629242] 1118855912:Entered
[  463.631383] 1118855912:SMD QRTR driver probed
[  463.633320] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  463.633334] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  463.633688] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  463.641981] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  464.864191] Fatal error on slpi!
[  464.864266] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_0:0x69:sns_stream_service.c:436:req_found.
[  464.864291] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  464.867315] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  464.867320] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  464.883697] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  464.883706] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  464.885643] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  464.885787] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  464.887190] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  464.887455] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  464.945581] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  465.007996] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  465.008139] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  465.015414] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  465.015420] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  465.015924] 1118855912:Entered
[  465.016498] 1118855912:SMD QRTR driver probed
[  465.019954] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  465.023578] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  465.023627] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  465.029301] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  466.256347] Fatal error on slpi!
[  466.256432] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_0:0x69:sns_stream_service.c:436:req_found.
[  466.256456] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  466.259074] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  466.259079] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  466.275522] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  466.275806] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  466.277897] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  466.278247] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  466.279336] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  466.279500] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  466.338642] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  466.399095] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  466.399127] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  466.405824] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  466.405830] 1118855912:Entered
[  466.405832] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  466.406031] 1118855912:SMD QRTR driver probed
[  466.407495] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  466.411445] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  466.412552] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  466.419864] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  467.641878] Fatal error on slpi!
[  467.641957] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  467.641983] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  467.644997] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  467.645001] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  467.656914] rpmh_rsc_send_data: 19 callbacks suppressed
[  467.656915] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  467.656940] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  467.658270] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  467.658280] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  467.658668] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  467.659779] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  467.661747] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  467.661931] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  467.716145] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  467.778657] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  467.778688] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  467.778800] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  467.786334] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  467.786340] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  467.786864] 1118855912:Entered
[  467.787109] 1118855912:SMD QRTR driver probed
[  467.790948] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  467.795012] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  467.795026] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  467.800505] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  469.020359] Fatal error on slpi!
[  469.020432] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_0:0x69:sns_stream_service.c:436:req_found.
[  469.020458] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  469.022405] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  469.022408] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  469.034300] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.034318] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.034337] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.034348] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.034360] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.034371] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.034382] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  469.040876] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  469.040986] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  469.041166] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  469.041336] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  469.042154] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  469.042336] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  469.101055] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  469.161468] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  469.161515] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  469.168694] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  469.168702] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  469.168830] 1118855912:Entered
[  469.169190] 1118855912:SMD QRTR driver probed
[  469.170647] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  469.177803] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  469.178019] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  469.183206] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  470.408342] Fatal error on slpi!
[  470.408426] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_0:0x69:sns_stream_service.c:436:req_found.
[  470.408454] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  470.410929] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  470.410934] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  470.428290] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  470.428426] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  470.430688] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  470.430827] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  470.431771] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  470.431903] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  470.491572] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  470.554485] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  470.554528] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  470.561372] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  470.561377] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  470.562108] 1118855912:Entered
[  470.562411] 1118855912:SMD QRTR driver probed
[  470.567554] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  470.569456] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  470.569501] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  470.575413] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  471.808443] Fatal error on slpi!
[  471.808525] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_0:0x69:sns_stream_service.c:436:req_found.
[  471.808553] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  471.811212] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  471.811217] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  471.827600] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  471.827611] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  471.829473] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  471.829658] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  471.830216] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  471.830370] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  471.885397] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  471.947763] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  471.947797] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  471.955860] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  471.955865] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  471.957236] 1118855912:Entered
[  471.958811] 1118855912:SMD QRTR driver probed
[  471.959979] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  471.962094] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  471.962128] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  471.969208] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  473.190744] Fatal error on slpi!
[  473.190818] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_0:0x69:sns_stream_service.c:436:req_found.
[  473.190843] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  473.193872] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  473.193878] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  473.205809] rpmh_rsc_send_data: 11 callbacks suppressed
[  473.205810] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  473.205837] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  473.206983] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  473.206995] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  473.207337] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  473.210007] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  473.210544] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  473.211534] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  473.267488] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  473.329966] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  473.330083] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  473.337309] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  473.337313] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  473.337774] 1118855912:Entered
[  473.338098] 1118855912:SMD QRTR driver probed
[  473.339277] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  473.343685] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  473.343696] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  473.351954] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  474.571003] Fatal error on slpi!
[  474.571089] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  474.571117] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  474.574318] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  474.574322] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  474.586295] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  474.586323] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  474.587793] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  474.587808] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  474.592474] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  474.592629] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  474.593885] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  474.594047] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  474.648774] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  474.710135] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  474.710177] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  474.716090] 1118855912:Entered
[  474.716142] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  474.716147] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  474.716593] 1118855912:SMD QRTR driver probed
[  474.718796] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  474.724814] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  474.724833] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  474.730730] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  475.966509] Fatal error on slpi!
[  475.966596] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  475.966624] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  475.969220] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  475.969224] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  475.981165] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  475.981191] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  475.983399] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  475.983410] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  475.987724] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  475.987865] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  475.989595] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  475.989762] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  476.047626] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  476.107799] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  476.107835] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  476.114130] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  476.114135] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  476.116482] 1118855912:Entered
[  476.119264] 1118855912:SMD QRTR driver probed
[  476.121677] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  476.122117] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  476.122133] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  476.130800] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  477.367311] Fatal error on slpi!
[  477.367394] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  477.367420] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  477.370476] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  477.370480] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  477.382395] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  477.382419] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  477.383806] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  477.383817] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  477.384136] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  477.384263] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  477.384816] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  477.385120] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  477.443490] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  477.506162] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  477.506193] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  477.506290] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  477.512803] 1118855912:Entered
[  477.513075] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  477.513079] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  477.513148] 1118855912:SMD QRTR driver probed
[  477.515628] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  477.521213] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  477.521250] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  477.525781] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  503.375461] Fatal error on slpi!
[  503.375541] slpi subsystem failure reason: err_qdi.c:1079:EF:sensor_process:0x1:SNS_SEE_I_1:0x68:sns_stream_service.c:436:req_found.
[  503.375566] subsys-restart: subsystem_restart_dev(): Restart sequence requested for slpi, restart_level = RELATED.
[  503.378697] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is restarting
[  503.378700] subsys-restart: subsystem_shutdown(): [kworker/u19:0:2054]: Shutting down slpi
[  503.390607] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30030
[  503.390638] qcom_rpmh DRV:apps_rsc TCS Busy, retrying RPMH message send: addr=0x30040
[  503.391897] coresight-remote-etm soc:ssc_etm0: Connection disconnected between QMI handle and 8 service
[  503.391976] sysmon-qmi: ssctl_del_server: Connection lost between QMI handle and slpi's SSCTL service
[  503.392269] adsprpc: fastrpc_rpmsg_remove: closed rpmsg channel of slpi
[  503.393461] adsprpc: fastrpc_restart_notifier_cb: received RAMDUMP notification for slpi
[  503.394021] subsys-restart: subsystem_powerup(): [kworker/u19:0:2054]: Powering up slpi
[  503.394144] subsys-pil-tz 5c00000.qcom,ssc: slpi: loading from 0x0000000088c00000 to 0x000000008a600000
[  503.455432] subsys-pil-tz 5c00000.qcom,ssc: slpi: Brought out of reset
[  503.515539] subsys-pil-tz 5c00000.qcom,ssc: Subsystem error monitoring/handling services are up
[  503.515566] subsys-pil-tz 5c00000.qcom,ssc: slpi: Power/Clock ready interrupt received
[  503.521829] 1118855912:Entered
[  503.521855] adsprpc: fastrpc_restart_notifier_cb: slpi subsystem is up
[  503.521861] subsys-restart: subsystem_restart_wq_func(): [kworker/u19:0:2054]: Restart sequence for slpi completed.
[  503.522191] 1118855912:SMD QRTR driver probed
[  503.523845] adsprpc: fastrpc_rpmsg_probe: opened rpmsg channel for slpi
[  503.530404] sysmon-qmi: ssctl_new_server: Connection established between QMI handle and slpi's SSCTL service
[  503.530421] coresight-remote-etm soc:ssc_etm0: Connection established between QMI handle and 8 service
[  503.535973] diag: In diag_send_peripheral_buffering_mode, buffering flag not set for 3
[  928.349273] perf: interrupt took too long (2502 > 2500), lowering kernel.perf_event_max_sample_rate to 79750

[ 1413.270080] perf: interrupt took too long (3128 > 3127), lowering kernel.perf_event_max_sample_rate to 63750
[ 2701.369922] perf: interrupt took too long (3915 > 3910), lowering kernel.perf_event_max_sample_rate to 51000
```

FCv2 QGC mavlink status when communication working
```
nsh> mavlink status

instance #0:
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: OFF
    rates:
      tx: 1322.9 B/s
      txerr: 0.0 B/s
      tx rate mult: 0.050
      tx rate max: 1200 B/s
      rx: 4758.9 B/s
      rx loss: 128.0%
    Received Messages:
      sysid:  1, compid:197, Total: 3287 (lost: 425347)
        msgid:    0, Rate:  0.3 Hz, last 0.15s ago
        msgid:  330, Rate:  7.3 Hz, last 0.18s ago
        msgid:  331, Rate: 12.1 Hz, last 0.05s ago
        msgid:   84, Rate: 11.6 Hz, last 0.08s ago
      sysid:  1, compid:196, Total: 37 (lost: 0)
        msgid:    0, Rate:  0.3 Hz, last 2.44s ago
    FTP enabled: YES, TX enabled: YES
    mode: Onboard
    Forwarding: On
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @115200)
```

FCv2 QGC mavlink status when "connection to mission computer lost"
```
mavlink status

instance #0:
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: OFF
    rates:
      tx: 1621.3 B/s
      txerr: 0.0 B/s
      tx rate mult: 0.050
      tx rate max: 1200 B/s
      rx: 0.0 B/s
      rx loss: 125.6%
    Received Messages:
      sysid:  1, compid:197, Total: 6025 (lost: 765633)
      sysid:  1, compid:196, Total: 69 (lost: 0)
    FTP enabled: YES, TX enabled: YES
    mode: Onboard
    Forwarding: On
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @115200)
```

Please update if J18 is usable or not for MAVLink?

## Reply by Eric Katzfey (ModalAI staff) · 2025-11-03 21:08:43 UTC (in reply to ravi)

@ravi J18 should work. Let's try this one step at a time and see if we can figure out where the issue is. Start by disabling the voxl-mavlink-server, voxl-px4, etc. services and power cycle the VOXL 2. With port set to 12 and baudrate at 57600 does `voxl-mavlink-server -z` show connection with autopilot? If so, does it stay connected? And can you connect GCS? If all of that works fine, power cycle the VOXL 2 and just make sure that it reliably works. Let me know how all that goes before we move to the next step.

## Reply by Eric Katzfey (ModalAI staff) · 2025-11-03 21:10:12 UTC (in reply to ravi)

@ravi Keep in mind you must power cycle the VOXL 2 between each thing you do because the DSP (SLPI) won't cleanly shut down and if you try to start voal-mavlink-server again it will fail.

## Reply by ravi · 2025-11-05 20:58:05 UTC

@Eric-Katzfey 

I tested J18(VOXl2) SDK 1.5 and J1(FCv2) firmware V1.15.2.
VOXL2 is connected with FCv2.
FCv2 connected with QGC.

I rebooted VOXL2. But after a few minutes, MAVLink connection broke.

I will test J18 later.

Now, to move forward. using J9 for 5G modem and connected with J1 FCv2.
Connection seems stable. Now the connection is lost.

But now the major issue is that RX loss is 124%.
I disabled messages 331,84 and configured 330 @ 10Hz.

Still, I am experiencing a 21.3% Rx loss.
The only messages visible is Heatbeat(0) and Obstacle_distance(330).

I did check. How many messages does FCv2 lose?
seems to be successfully receiving only 10-11 messages per second
and losing 254 messages per second.
So, actually getting only <5% messages successfully.

![4e35a065-b957-4166-9e5c-3940960280a1-image.png](https://forum.modalai.com/assets/uploads/files/1762375520154-4e35a065-b957-4166-9e5c-3940960280a1-image.png) 

### mavlink status with VOXL2 default configuration of vision-hub 
```

instance #0:
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: ON
    rates:
      tx: 639.8 B/s
      txerr: 0.0 B/s
      tx rate mult: 0.302
      tx rate max: 1200 B/s
      rx: 13464.5 B/s
      rx loss: 124.4%
    Received Messages:
      sysid:  1, compid:197, Total: 97158 (lost: 12227092)
        msgid:    0, Rate:  1.0 Hz, last 0.04s ago
        msgid:   84, Rate: 31.3 Hz, last 0.01s ago
        msgid:  331, Rate: 32.4 Hz, last 0.03s ago
        msgid:  330, Rate: 20.3 Hz, last 0.02s ago
      sysid:  1, compid:196, Total: 1135 (lost: 0)
        msgid:    0, Rate:  0.9 Hz, last 0.08s ago
    FTP enabled: YES, TX enabled: YES
    mode: Normal
    Forwarding: On
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @230400)
```

### mavlink status with VOXL2 disabled 331, 84, and 331@10Hz in vision-hub config
```
instance #0:
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: OFF
    rates:
      tx: 1106.7 B/s
      txerr: 0.0 B/s
      tx rate mult: 0.310
      tx rate max: 1200 B/s
      rx: 1828.2 B/s
      rx loss: 21.3%
    Received Messages:
      sysid:  1, compid:197, Total: 7820 (lost: 180596)
        msgid:    0, Rate:  1.0 Hz, last 0.37s ago
        msgid:  330, Rate: 10.0 Hz, last 0.06s ago
      sysid:  1, compid:196, Total: 672 (lost: 0)
        msgid:    0, Rate:  0.9 Hz, last 0.97s ago
    FTP enabled: YES, TX enabled: YES
    mode: Normal
    Forwarding: On
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @921600)
```

### mavlink status with VOXL2 disabled 331, 84, and 331@10Hz in vision-hub config
- if MAVLink mode changed to onboard mode
```
instance #0:
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: OFF
    rates:
      tx: 21751.5 B/s
      txerr: 0.0 B/s
      tx rate mult: 1.000
      tx rate max: 46080 B/s
      rx: 2429.8 B/s
      rx loss: 82.9%
    Received Messages:
      sysid:  1, compid:197, Total: 44616 (lost: 3811731)
        msgid:    0, Rate:  1.0 Hz, last 0.51s ago
        msgid:  330, Rate: 10.0 Hz, last 0.01s ago
        msgid:  111, Rate:100.9 Hz, last 0.08s ago
      sysid:  1, compid:196, Total: 1358 (lost: 0)
        msgid:    0, Rate:  0.9 Hz, last 1.02s ago
    FTP enabled: YES, TX enabled: YES
    mode: Onboard
    Forwarding: On
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @921600)
```

- Is it expected behaviour?
- How to debug Rx loss?
Also, there is a huge difference in success and loss.
- Is PX4 filtering or discarding packets?
- Originally, we were losing 95% messages, and it is showing 21.3% loss.
- How to calculate Rx loss because the actual is way higher?

## Reply by Eric Katzfey (ModalAI staff) · 2025-11-06 01:21:11 UTC (in reply to ravi)

@ravi It's acting like you have a mismatch in baudrate settings for the UARTs. Try setting the baudrate to 115200 for port 12 in /etc/modalai/voxl-mavlink-server.conf. In order to setup the FCv2 connect to QGC with USB and set SER_TEL1_BAUD to 115200 8N1, then reboot. Make sure you are connected to the TELEM1 connector on FCv2 and J18 on VOXL 2.

## Reply by ravi · 2025-11-06 13:12:44 UTC (in reply to Eric Katzfey)

@Eric-Katzfey 

As said,
I will test J18 later.

Currently, I am using [J9 of a 5G](https://docs.modalai.com/5G-Modem-datasheet/#j9-uart--i2c) modem and connected with [J1  of FCv2](https://docs.modalai.com/flight-core-v2-datasheets-connectors/#j1---telem1--uart7--voxl-mavlink-default-port).

Connection seems stable. using a 921600 baud rate with port 2.
The major issue is RX loss.

seeing 95% message loss, as I explained in an earlier post.

below is mavlink status visible on QGC mavlink console:
```
nsh> mavlink status

instance #0:
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: OFF
    rates:
      tx: 1106.7 B/s
      txerr: 0.0 B/s
      tx rate mult: 0.310
      tx rate max: 1200 B/s
      rx: 1828.2 B/s
      rx loss: 21.3%
    Received Messages:
      sysid:  1, compid:197, Total: 7820 (lost: 180596)
        msgid:    0, Rate:  1.0 Hz, last 0.37s ago
        msgid:  330, Rate: 10.0 Hz, last 0.06s ago
      sysid:  1, compid:196, Total: 672 (lost: 0)
        msgid:    0, Rate:  0.9 Hz, last 0.97s ago
    FTP enabled: YES, TX enabled: YES
    mode: Normal
    Forwarding: On
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @921600)

```

As above, the RX loss showing is 21.3% which is huge. 
It is in normal mode. If I change the mavling mode to onboard, it is an 83% loss. and with vision hub odomatry, distance massages it is getting worst like 125%.

Now. This Rx loss does not match the number.
```
      sysid:  1, compid:197, Total: 7820 (lost: 180596)
```
As per this MAVLink status, the total successfully received messages are 7820, and the lost are 180596.
So, actual loss is (180596/(7820+180596)) = 95.8%.
And it is showing only 21.3%.

So, MAVLink is working between VOXl2 and FCv2. Currently using UART port 2 of VOXl2, not 12. I will debug it later. Once setup is complete.

## Reply by Eric Katzfey (ModalAI staff) · 2025-11-06 14:56:41 UTC (in reply to ravi)

@ravi Here is what I see on my setup testing with baudrate 921600, TELEM1 (J1), and J18 (12):
```
nsh> mavlink status

instance #0:
    GCS heartbeat valid
    mavlink chan: #0
    type:        GENERIC LINK OR RADIO
    flow control: OFF
    rates:
      tx: 1773.5 B/s
      txerr: 0.0 B/s
      tx rate mult: 1.000
      tx rate max: 46080 B/s
      rx: 570.5 B/s
      rx loss: 0.0%
    Received Messages:
      sysid:255, compid:190, Total: 2341 (lost: 57)
        msgid:  126, Rate:  nan Hz, last 0.01s ago
        msgid:    4, Rate:  0.1 Hz, last 2.27s ago
        msgid:    0, Rate:  1.0 Hz, last 0.58s ago
        msgid:   69, Rate: 29.1 Hz, last 0.02s ago
      sysid:  1, compid:197, Total: 108 (lost: 0)
        msgid:    0, Rate:  1.0 Hz, last 0.86s ago
    FTP enabled: YES, TX enabled: YES
    mode: Normal
    Forwarding: Off
    MAVLink version: 2
    transport protocol: serial (/dev/ttyS6 @921600)
    ping statistics:
      last: 14.29 ms
      mean: 31.46 ms
      max: 135.44 ms
      min: 13.21 ms
      dropped packets: 0
```

## Reply by Eric Katzfey (ModalAI staff) · 2025-11-06 14:59:54 UTC (in reply to ravi)

@ravi I'm suspecting you have a bad cable or the cable is subject to some interference. Can you try this on a benchtop with just a VOXL 2 and an FC v2 and no other components? Is it currently integrated into a custom drone? Can you look at the signal quality on the TX and RX UART lines with an oscilloscope?