SAMD21G Mini built-in LED: Blink sketch

My SAMD21G mini breakout is behaving strangely. To debug it, I uploaded the standard “Blink” sketch, but I don’t see anything flashing. “Blink” uses a LED_BUILTIN variable to define the LED pin. I assume the SAMD21 has a built-in LED and should react to the LED_BUILTIN variable?

it should… de blue led is connected to pin 13. Instead of LED_BUILTIN variable, set the blink-pin as 13.

https://learn.sparkfun.com/tutorials/sa … mple-blink