I was hoping someone could please help me.
I have a project using the SAMD21 and ASF4. The SAMD21 communicates to an external peripheral via USART.
I needed to add an External IRQ to listen for a button action. This IRQ also works.
The problem is when I added the IRQ to the project via Atmel start. The USART then fails on its first "io_write". If I disable the IRQ (uncomment from the driver_init.c file) the USART will start working again.
The both work stand alone but if I attempt to run both together (USART and IRQ) then the USART will always fail (as shown in attached callstack)
Would this be due to a clock configuraton? Im quite stuck on this issue for a few days now and am hoping someone could help even point me in the right direction.
Thank you in advance