CRASH :( Internal Errors 0x800

JetPilot · April 8, 2025, 5:24pm

I have a Matek F765 Wing with Stable version 4.5.7 official that has been working perfectly for a very long time, but the other day while flying I got " Internal Errors 0x800 " followed by what appeared to be a reset and everything just stopped working and locked up with the crazy text covering the video… See pictures below.

Does anyone have any ideas on what could cause this ???

menschel · April 8, 2025, 5:54pm

Can be the SD Card. If yes, check integrity.
Are you reading the OSD Font from SD Card by any chance?
It would explain why something with OSD is happening in the aftermath.

Chip Watchdog if enabled relies on being reset by main loop. If main loop is stuck, it resets the chip which likely crashes the plane in the process.

JetPilot · April 8, 2025, 7:00pm

Hi Menschel,

Thank you for the reply ! There was no SD card in the Matek 765, empty slot and fonts were Ardupilot default. I just have no idea why this would happen after working great for over 2 years.

menschel · April 9, 2025, 12:04pm

If you familiar with STM Cube Programmer you may want to upload the chip’s flash memory and compare it against the original binary. On-chip flash wears out after 10.000-50.000 erase cycles, depends on the specification. I don’t know where it writes the logs when you have no sd card for example.

OK, 10k guaranteed, table 59
https://www.st.com/resource/en/datasheet/stm32f767zi.pdf

menschel · April 9, 2025, 6:13pm

After some digging,

Watchdog Reset → Error Message

github.com/ArduPilot/ardupilot

libraries/AP_Vehicle/AP_Vehicle.cpp

master


      
          
          // if there's been a watchdog reset, notify the world via a statustext:
          void AP_Vehicle::send_watchdog_reset_statustext()
          {
              if (!hal.util->was_watchdog_reset()) {
                  return;
              }
              const AP_HAL::Util::PersistentData &pd = hal.util->last_persistent_data;
              (void)pd;  // in case !HAL_GCS_ENABLED
              GCS_SEND_TEXT(MAV_SEVERITY_CRITICAL,
                              "WDG: T%d SL%u FL%u FT%u FA%x FTP%u FLR%x FICSR%u MM%u MC%u IE%u IEC%u TN:%.4s",
                              pd.scheduler_task,
                              pd.semaphore_line,
                              pd.fault_line,
                              pd.fault_type,
                              (unsigned)pd.fault_addr,
                              pd.fault_thd_prio,
                              (unsigned)pd.fault_lr,
                              (unsigned)pd.fault_icsr,
                              pd.last_mavlink_msgid,
                              pd.last_mavlink_cmd,

So we have some Task 41, Semaphore Line 0, Fault Line 217, fault type 3, fault address 2.

I have not yet figured out how to index the task from this array and find out the module behind it.

github.com/ArduPilot/ardupilot

ArduPlane/Plane.cpp

master


      
          - class name of method to be called
          - instance on which to call the method
          - method to call on that instance
          - rate (in Hertz) at which the method should be called
          - expected time (in MicroSeconds) that the method should take to run
          - priority (0 through 255, lower number meaning higher priority)
          
          FAST_TASK entries are run on every loop even if that means the loop
          overruns its allotted time
          */
          const AP_Scheduler::Task Plane::scheduler_tasks[] = {
                                    // Units:   Hz      us
             FAST_TASK(ahrs_update),
             FAST_TASK(update_control_mode),
             FAST_TASK(stabilize),
             FAST_TASK(set_servos),
             SCHED_TASK(read_radio,             50,    100,   6),
             SCHED_TASK(check_short_failsafe,   50,    100,   9),
             SCHED_TASK(update_speed_height,    50,    200,  12),
             SCHED_TASK(update_throttle_hover, 100,     90,  24),
             SCHED_TASK_CLASS(RC_Channels,     (RC_Channels*)&plane.g2.rc_channels, read_mode_switch,           7,    100, 27),

Trying to guess, BUSFAULT…

https://documentation-service.arm.com/static/61084e4a3d73a34b640e31eb

JetPilot · April 10, 2025, 1:04am

Hi Menschel,

WOW, that is awesome you got that much detail from this !!! Thank you for taking the time to look into this. Also, I have many, many hours flying this flight controller over the past few years, it was normal for me to get a 4+ hour flights on this plane. My biggest problem until now was wearing out servos… So I guess I have my answer:

Make sure I have an SD Card in the flight controller to prevent this from happening again ???
If I use Cube Programmer to do a complete erase on the Matek F765, and reinstall Ardupilot + bootloader, would it be safe to use this flight controller again ???

menschel · April 10, 2025, 5:49am

Can’t say for sure, task index is obscured by the features compiled in, but some logger tasks are in the possible range for index 41, so I would recommend using an SD card.
Before you erase the MCU, backup your parameters and make an upload with Cube Programmer.
Then you can compare the hex in an editor or ordinary diff tool.
There is code flash and data flash sectors. Compare if there is anything corrupted in code flash.

jinchengde · April 10, 2025, 8:17am

do you use a rpm sensor?

JetPilot · April 10, 2025, 5:50pm

Hi Jinchengde,

No RPM or other sensors, just the flight controller and GPS.