@nervencid The attenuation setting change the input voltage range for the ADC. With ATTN_D its is 0-1V, with ATTN_11DB it is ~0-3V. The range of the numbers you read form the ADC is always 0-4095, only at a different input voltage. The factor associated with a dB attenuation number is 10**(dB_number/20). So for 0 it is 1, for 11 it is 3.548, for 6 it is 1.995