 
     ///// ADC0 ////
     // reference can be ADC_REFERENCE::REF_3V3, ADC_REFERENCE::REF_1V2 (not for Teensy LC) or ADC_REFERENCE::REF_EXT.
-    //adc->setReference(ADC_REFERENCE::REF_1V2, ADC_NUM::ADC_0); // change all 3.3 to 1.2 if you change the reference to 1V2
+    //adc->setReference(ADC_REFERENCE::REF_1V2, ADC_0); // change all 3.3 to 1.2 if you change the reference to 1V2
 
     adc->setAveraging(16); // set number of averages
     adc->setResolution(16); // set bits of resolution

bool test_pullup_down(bool pullup) {
    uint8_t mode = pullup ? INPUT_PULLUP : INPUT_PULLDOWN;

    const int max_val = adc->getMaxValue(ADC_NUM::ADC_0);

    bool pass_test = true;


    adc->setAveraging(1);
    timeElapsed = 0;
    for(uint32_t i=0; i<num_samples; i++) {
        adc->analogRead(A0, ADC_0);
    }
    float one_avg_time = timeElapsed/num_samples;

