can i use -4.8v as a reference signal

Projects Programming
1

Im in need of help. i need to no if its possible to read a neg 4.8 signal to = high an 0v to signal low. or must high be +
thanks
kevin

2

I don't think you can read a negative voltage, it will damage the chip.

Maybe if you invert the signal before it reaches the pin then you maybe work with it that way, but then your positive signal will be negative so I dont think that will work, either.

3

Only positive voltage inputs (0 to 5V) to Arduino are allowed.

However, a simple circuit could be used to invert your signal.

4

Hi,
You can use an op amp and invert the signal.

5

jremington:
Only positive voltage inputs (0 to 5V) to Arduino are allowed.

However, a simple circuit could be used to invert your signal.

Very useful tidbit of advice, thanks.

6

Yes but that will invert the normally positive signal too.

7

Perhaps you should tell us the rest of the story!

Paul