Hi Roberto,
ADC1 is currently supported in esp-idf, however the API documentation seems to be missing from the API reference. We'll get this fixed ASAP.
In the meantime, you can find the relevant functions and some example code here:
https://github.com/espressif/esp-idf/bl ... iver/adc.h
There is currently a known issue with the ADC, the output values are not fully linear and we need to add compensation for ADC characterisation to the driver. We are working on this.
Angus