MKRWAN1310 what caused the reset?

[rw950431]

In general there are at least 3 different ways a reset can occur and the setup() routine be called

-Power on
-Watchdog fired
-Wake after deep sleep.

Using the MKRWAN1310 board is there any method of finding out which of the above occurred?

[MartinL]

Hi @rw950431

It's possible to determine which reset occured using the SAMD21's RCAUSE register:

// Check the RCAUSE register reset bits
void setup()
{
  Serial.begin(115200);                  // Initialise the native USB port
  while (!Serial);                       // Wait for the console to open
  
  Serial.print(F("SYST: "));
  Serial.println(PM->RCAUSE.bit.SYST);   // System (software) reset
  Serial.print(F("WDT: "));
  Serial.println(PM->RCAUSE.reg & PM_RCAUSE_WDT);   // Watchdog timer reset (use of WDT bit causes compilation error)
  Serial.print(F("EXT: "));
  Serial.println(PM->RCAUSE.bit.EXT);    // External (reset button) reset
  Serial.print(F("POR: "));
  Serial.println(PM->RCAUSE.bit.POR);    // Power-on reset
  Serial.println();
}

void loop() {}

The RCAUSE register also includes brown out detection bits: BOD33 and BOD12.

[rw950431]

Thanks @MartinL exactly what I wanted.

Knowing the keywords enabled me to also find

Using the SAM D21's brown-out detector - Thea Flowers

https://microchipdeveloper.com/32arm:samd21-pm-overview

Which were of interest to me also