How to set the prescale for ADC1?, I would like to set prescale for ADC1 and what is specification prescale ADC1.

Hi.
By default the analogRead() functions returns values between 0 and 4095 (it is 12 bit resolution).
To change the resolution you can use the analogReadResolution() function that accepts as argument a number between 1 and 16.
For example, if you want to get values between 0 and 1023, you pass 10 as argument (10 bit resolution).
If you want to get values between 0 and 255, you pass 8 as argument (8 bit resolution), and so on…
You can find more useful information about analog reading in the following link:
https://github.com/espressif/arduino-esp32/blob/master/cores/esp32/esp32-hal-adc.h
I hope this helps,
Regards,
Sara

Thanks a lot my teacher. 🙂