muddy0409
- 28th April 2009, 00:58
Hi all.\
Got aa question for the geniuses out there.
I am reading an analogue voltage of 0 to 13.8vDC via a resistor divider to drop it down to 5v max. The divider has one resistor from the pin to ground and one from the pin to the input voltage. Therefore the pin is never actually "floating", but floating is one of the input conditions that I want to read. With a conection from the input resistor to the voltage a divided voltage will be read by the pin.
So far so good. This bit works perfectly.
However when there is no contact between the input resistor and the voltage, the second resistor will pull the pin down to ground. This will give the same reading as if the input was touching 0 volts. So far I have not been able to figure out just how to differentiate between the actual 0 Volt reading and the input floating. ?????
Intriguing, ain't it?
Regards.
Got aa question for the geniuses out there.
I am reading an analogue voltage of 0 to 13.8vDC via a resistor divider to drop it down to 5v max. The divider has one resistor from the pin to ground and one from the pin to the input voltage. Therefore the pin is never actually "floating", but floating is one of the input conditions that I want to read. With a conection from the input resistor to the voltage a divided voltage will be read by the pin.
So far so good. This bit works perfectly.
However when there is no contact between the input resistor and the voltage, the second resistor will pull the pin down to ground. This will give the same reading as if the input was touching 0 volts. So far I have not been able to figure out just how to differentiate between the actual 0 Volt reading and the input floating. ?????
Intriguing, ain't it?
Regards.