1k series resistor, schottky diode clamps to the 0V, 5V rails, LM339 comparator (compare to about 1V?), pull-up resistor, Arduino pin
(Actually make that 4k7 series resistor, don't want to pull the 5V rail up in voltage...)
1k series resistor, schottky diode clamps to the 0V, 5V rails, LM339 comparator (compare to about 1V?), pull-up resistor, Arduino pin
(Actually make that 4k7 series resistor, don't want to pull the 5V rail up in voltage...)