I’ve been working on a new aquatic vehicle. 1st test went good. Powered up this afternoon at home to check some parameters and Mission Planner repeats InternalError0x800 constantly. What is this error?
Using a Pixhawk 1. I’ve tried to verify if it is a 1mb or 2mb board but have not been able to. Thanks in advance.

This error means STM32 watchdog is triggering, according to how much I’m familiar with this issue that can happen in several cases like when there is some delay in main thread if you are customising the firmware, and it can also occur in case of hardware faults, if you like to find the source I suggest to look at this thread Low Level Debugging the STM32 and Ardupilot

What does QGC report it as?

This is a 1Mb Pixhawk I have:

Thanks for reminding my about QGC. I was using MP and could not get anywhere on the terminal screen. Its a 2MB pixhawk. Thanks. I searched “internal error 0x800” and have some ideas to try.

Reflashed with plane and then rover again and problem seems to be gone.