Parameters for full ESP32 chip. For others, refer to documentation.
ADC_ATTEN_DB_0
100mV ~ 950mVADC_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)