struct adc_module adc_instance;
struct
adc_config config_adc;
adc_get_config_defaults(&config_adc);
#if !(SAML21)
#if !(SAMC21)
config_adc.gain_factor = ADC_GAIN_FACTOR_DIV2;
#endif
config_adc.resolution = ADC_RESOLUTION_10BIT;
#endif
config_adc.clock_prescaler = ADC_CLOCK_PRESCALER_DIV16;
config_adc.reference = ADC_REFERENCE_INTVCC1;
config_adc.positive_input = ADC_POSITIVE_INPUT_PIN4;
config_adc.freerunning =
true;
config_adc.left_adjust =
false;
#if (SAMC21)
adc_init(&adc_instance, ADC1, &config_adc);
#else
adc_init(&adc_instance, ADC, &config_adc);
#endif
adc_enable(&adc_instance);