MPLAB® Harmony v3 Peripheral Libraries on SAM D21: Step 3
Configure Pins for Switch and LED
Configure Switch Button Pin with the External Interrupt Controller (EIC) to Generate an Interrupt
In this step, the switch button will be configured as shown in the following image.
In MPLAB® Code Configurator (MCC), select the Pin Settings tab and then scroll down to the PORT pin PA15 (Pin Number 32) in the Pin ID column and configure PA15 as an external interrupt pin for switch functionality as shown in the following image. Internal pull-up is enabled to avoid false edge detection as there is no external pull-up on the SAM D21 Xplained Pro Evaluation Kit.
Add the External Interrupt Controller (EIC) to the project.
Under the left side tab, Resource Management (MCC), go to Device Resources and expand Libraries > Harmony > Peripherals > EIC.
Select and double-click on EIC to add the EIC module to the project.
Configure the EIC block to generate an interrupt every time the user presses the switch SW0 as shown in the following image, and enable filter functionality to avoid electrical noise on the switch pin.
Configure LED Pin
In this step, the user LED will be configured as per the following image.
Select the MCC Pin Settings tab and then scroll down to the PORT pin PB30 (Pin Number 59) in the Pin ID column and configure PB30 as an output pin for LED functionality as shown in the following image.
Rename the Default Main File
Under the Project Graph tab, click on System, and configure as shown in the following image to give the name of your liking to the default template main file generated by MCC.