@jmarcelino: Yes, Ive read that. But you would still have to compensate for the non-zero range (at least in your circuit). So at the moment and with limited requirements for precision, using the lower attenuation variants 0 and 6db and simply adding an offset would be sufficient as compensation. If you need precise values, yes, then an external ADC is anyhow recommended. B.T.W. Is there still the option to use the ADC in 10 bit mode, like by an option res = xx in the channel set-up?