Failed to decode packet: InvalidCRC

[tuupola]

Downloaded latest release and tested with a PX4 compiled from latest master. I get screen full of Failed to decode packet: InvalidCRC errors. I can still see MAVLink messages in the web interface.

Is this expected behavior or am I missing something?

$ stty -F /dev/ttyACM0
speed 460800 baud; line = 0;
min = 1; time = 0;
-brkint -icrnl -imaxbel
-opost
-isig -icanon -iexten -echo
$ mavlink-server "serial:///dev/ttyACM0?baudrate=460800"                           
2026-03-26T11:07:03.574318Z  INFO main ThreadId(01) src/main.rs:12: mavlink-server, version: 0.1.0-11348440acf77d3f1ab16046d12cb2930235f58a, build date: 2026-02-14
2026-03-26T11:07:03.574420Z  INFO main ThreadId(01) src/main.rs:19: Starting at 2026-03-26T13:07:03
2026-03-26T11:07:03.574466Z DEBUG main ThreadId(01) src/main.rs:23: Command line call: mavlink-server serial:///dev/ttyACM0?baudrate=460800
2026-03-26T11:07:03.574526Z DEBUG main ThreadId(01) src/main.rs:24: Command line input struct call: Args {
    endpoints: [
        Serial {
            name: ArcSwapAny(
                "Serial",
            ),
            uuid: 86f8a62c-9443-5cf0-90b0-b74a0c85c49a,
            port_name: "/dev/ttyACM0",
            baud_rate: 460800,
            on_message_input: Callback,
            on_message_output: Callback,
            stats: RwLock {
                data: AccumulatedDriverStats {
                    name: "Serial",
                    driver_type: "Serial",
                    stats: AccumulatedDriverStatsInner {
                        input: None,
                        output: None,
                    },
                },
            },
        },
    ],
    verbose: false,
    web_server: 0.0.0.0:8080,
    enable_tracing_level_log_file: false,
    log_path: Some(
        "./logs",
    ),
    streamreq_disable: true,
    udp_server_timeout: 10,
    mavlink_system_id: 1,
    mavlink_component_id: 191,
    mavlink_heartbeat_frequency: 1.0,
    send_initial_heartbeats: false,
    mavlink_version: 2,
    default_api_version: 1,
    allow_no_endpoints: false,
    zenoh_config_file: None,
}
2026-03-26T11:07:03.576252Z  INFO                 main ThreadId(01) src/lib/web/mod.rs:32: Running web server on address 0.0.0.0:8080
2026-03-26T11:07:03.577078Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 42860, calculated_crc: 56591 }
2026-03-26T11:07:03.577116Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 17537, calculated_crc: 33895 }
2026-03-26T11:07:03.577131Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 257, calculated_crc: 15100 }
2026-03-26T11:07:03.577155Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 16217, calculated_crc: 40198 }
2026-03-26T11:07:03.577210Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 22974, calculated_crc: 21301 }
2026-03-26T11:07:03.577226Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 59962, calculated_crc: 27852 }
2026-03-26T11:07:03.577242Z ERROR tokio-runtime-worker ThreadId(25) src/lib/drivers/generic_tasks.rs:73: Failed to decode packet: InvalidCRC { expected_crc: 30419, calculated_crc: 23807 }

[tuupola]

Seems to be related to PX4/PX4-Autopilot#25284. After reverting the patch and recompiling the InvalidCRC errors disappeared.

[joaoantoniocardoso]

Hi, thanks for reporting and tracing to the problem. At the moment we don't support signing, so that's expected not to work.

We welcome contributions in that direction.

[joaoantoniocardoso]

Note: the error is probably caused by our codec ignoring the signing bytes when doing CRC, so it needs to be implemented there, and then updated here.