I'm using a moisture sensor (SEED_1010) wich has an operational amplifier in it.
What exactly does it do? Ive read that it is an differential amplifier or something.
I have no idea what it does, ive searched multiple sites but I can't understand them.
Would anyone be possible to explain it to a newbie?
I'll add the module scheme
Also I can use the sensor as analog or digital.
What is the difference??
They will work the same no?
1: The diagram does NOT show a comparator, the feedback is to the - input; for a comparator it would be to the + input. Also a comparator has a logic output, the output here is marked A0 which to me would indicate its analog.
2: Yes the schematic has no relevance to the datasheet which as you say clearly shows a three terminal device, likely a transisiitor.
3: the schematic shows 1k resisitors which is an unusually low value for an op amp circuit.
We have a saying the OP might find useful: garbage in garbage out.
Nope, that would be the case if the was a dot where the feedback resistor path crossed the positive rail, but there isn't. This circuit uses negative feedback, and without
knowing exactly what the sensor itself is its hard to figure out what its actually supposed to do.
Of course if could be a mistake in the drawing and its a comparator - that's actually all too likely (there are missing dots on the lower part of the circuit for instance)...