#include"esp_adc_cal.h"//...voidsetup(){esp_adc_cal_characteristics_tadc_chars; esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_11, ADC_WIDTH_BIT_12,1100, &adc_chars);floatvref = adc_chars.vref;// Obtain the device ADC reference voltageSerial.print(F("vref is : ")); Serial...