Is there a module that turns the LED one input voltage drops below certain value? even better if this value can be defined in someway.
the range of detection is 0-12V and accuracy should be 0.1V.
well, I am looking for a battery level indicator. once the voltage drops below a value, the indicator lights a LED. Hope that make more sense than my previous description.
If its just voltage you want, look through the ebooks at the top of this website and search for "comparator". You will be able to exactly set the trip point you desire.