I have been having a terrible time getting Serial communication working on the SAM R34 chip using ATMEL Studio 7.
Normally when asking I get the response "Check the example" (Spoiler alert, there is no example)

Anyhow, The code I have and I got from an example is:

#include <asf.h>
#include "sio2host.h"
#include "lorawan_app.h"
#include "pulse_counter.h"
#include "serial.h"

struct usart_module usart_instance;



int main(void)
{
    system_init() ;
    delay_init() ;
    delay_ms(5) ;
    Enable_global_interrupt() ;
    sio2host_init() ;
    pulse_counter_init() ;
    lorawan_app_init() ;
    lorawan_app_configuration(ISM_JPN923) ;
    lorawan_app_join() ;
    
    
        struct usart_config config_usart;
        usart_get_config_defaults(&config_usart);
        #if(SAMR30E)
        {
            config_usart.baudrate    = 9600;
            config_usart.mux_setting = CDC_SERCOM_MUX_SETTING;
            config_usart.pinmux_pad0 = CDC_SERCOM_PINMUX_PAD0;
            config_usart.pinmux_pad1 = CDC_SERCOM_PINMUX_PAD1;
            config_usart.pinmux_pad2 = CDC_SERCOM_PINMUX_PAD2;
            config_usart.pinmux_pad3 = CDC_SERCOM_PINMUX_PAD3;
            while (usart_init(&usart_instance,
            CDC_MODULE, &config_usart) != STATUS_OK) {
            }
        }
        #else
        {
            config_usart.baudrate    = 9600;
            config_usart.mux_setting = EDBG_CDC_SERCOM_MUX_SETTING;
            config_usart.pinmux_pad0 = EDBG_CDC_SERCOM_PINMUX_PAD0;
            config_usart.pinmux_pad1 = EDBG_CDC_SERCOM_PINMUX_PAD1;
            config_usart.pinmux_pad2 = EDBG_CDC_SERCOM_PINMUX_PAD2;
            config_usart.pinmux_pad3 = EDBG_CDC_SERCOM_PINMUX_PAD3;
            while (usart_init(&usart_instance,
            EDBG_CDC_MODULE, &config_usart) != STATUS_OK) {
            }
        }
        #endif
        usart_enable(&usart_instance);
        
    
    usart_serial_putchar(usart_inst_t, 'a');
    while(1)
    {
        SYSTEM_RunTasks() ;
        lorawan_app_sleep() ;
    }
}

I am getting errors on the CDC_SERCOM_MUX_SETTING; and each of the CDC_SERCOM_PINMUX_PAD0; 0-3 lines.
This code came directly from this guide: https://asf.microchip.com/docs/latest/sam0.drivers.tcc.unit_test.saml21_xplained_pro/html/asfdoc_sam0_sercom_usart_basic_use_case.html
however, it seems to not be valid.

any ideas at all on how to get this to work? It would be much appreciated!

Source: Windows Questions C++