Input low voltage 0.47 VccHysteresis 0.05 VccInput high voltage 0.52 Vcc
Researching this forum, most replies mention 0.3Vcc for LOW (logic 0) and 0.6Vcc for HIGH (logic 1).Here's the results of some actual measurements on an UNO Rev3:
Researching this forum, most replies mention 0.3Vcc for LOW (logic 0) and 0.6Vcc for HIGH (logic 1).
THEY ARE NOT THE CORRECT VALUES. Try reading the datasheet. And you are the first I've seen to give those values on this forum.Mark
PS The datasheet link in the Uno's documentation no long works (Atmel have moved and rewritten the datasheet.)
Anything in between "floats" and gives an undefined result when read.
Incorrect. It's always defined.Within the hysteresis region:the result is 1 if previously above the hysteresis regionthe result is 0 if previously below the hysteresis region
low as < than (VIL - first row) as 0.3Vcc (aka 0.3 * Vcc) or 1.5V andhigh as >than (VIH - second row) as 0.6Vcc (aka 0.6 * Vcc) or 3.0V
VCC Volts Volts (Datasheet Page 391)Input low voltage 5.098 2.32 2.15 (Figure 33-26)Hysteresis 5.103 0.36 0.55 (Figure 33-27)Input high voltage 5.108 2.68 2.70 (Figure 33-25)