analogRead - divide by 1023 or 1024?

[Peter_n]

Thank you Runaway Pancake.

Then this is what I want (adding half a bit, to avoid rounding down)

float voltage = ((float) rawADC  + 0.5 ) / 1024.0 * 5.0;

The voltage would never be 0.0 and never be 5.0