WDT_T4 - Watchdog Library for Teensy 4

[defragster]

middle_hook seems to be used (error message when trying to use it).

not in base PJRC release. Perhaps that is when the watchdog starts up and that library uses it?
The error message should show where it is 'otherwise defined'?

 

[shawn]

middle_hook seems to be used (error message when trying to use it). early_hook (only using registers in Flashmem) did not work reliable at least at short times. Deactivating WDT3 in Callback works great.

I'm curious where you added the callback?

 

[defragster]

It needs to be declared as "C" code. Here is an example that was in an .INO file - same for .cpp:

extern "C" void startup_middle_hook(void);
extern "C" volatile uint32_t systick_millis_count;
FLASHMEM void startup_middle_hook(void) {
  pinMode( 2, OUTPUT );
  digitalWrite( 2, HIGH );
  // OPTIONAL FASTER STARTUP: force millis() to be 300 to skip startup delays
  // systick_millis_count = 300;
}

This may not be the issue - but the error message was not shown.