====== ADC ======
  * ADC1_CH0 = GPIO36
  * ADC1_CH1 
  * ADC1_CH2 
  * ADC1_CH3 = GPIO39
  * ADC1_CH6 = GPIO34
  * ADC1_CH7 = GPIO35
  * ADC1_CH4 = GPIO32
  * ADC1_CH5 = GPIO33

  * ADC2_CH0 = GPIO0
  * ADC2_CH1
  * ADC2_CH2 = GPIO2
  * ADC2_CH3 = GPIO15
  * ADC2_CH4 = GPIO13
  * ADC2_CH5 = GPIO12
  * ADC2_CH6 = GPIO14
  * ADC2_CH7 = GPIO27
  * ADC2_CH8 = GPIO25
  * ADC2_CH9 = GPIO26




===== Attenuation =====

Parameters for full ESP32 chip. For others, refer to documentation.

  * ''ADC_ATTEN_DB_0''    100mV ~ 950mV
  * ''ADC_ATTEN_DB_2_5''  100mV ~ 1250mV - range extended by about 2.5 dB (1.33 x)
  * ''ADC_ATTEN_DB_6''    150mV ~ 1750mV - range extended by about 6 dB (2 x)
  * ''ADC_ATTEN_DB_11''   150mV ~ 2450mV - range extended by about 11 dB (3.55 x)