I’m using an op-amp (LM358) to voltage follow a high impedance sensor and my question is this. What do I need to do on the op-amp output side to connect it to an Arduino analog input to read the voltages safely without burning anything up? Do I want to throw a resistor in between the op-amp and Arduino?
Stick Schematic:
[sensor}—{op-amp}—{? if any}—{Arduino]
Thanks ahead of time.
Just ensure that the op-amp’s output voltage never exceeds the processor’s input voltage limits.
A series resistor and diodes to the power + and ground is a common method.
What is the voltage powering the op-amp?
vcc is 5v.
the probe on the non inverting side outputs a voltage between 0v and 3v.
Erkle:
vcc is 5v.the probe on the non inverting side outputs a voltage between 0v and 3v.
Then you should be fine with just a small value resister is series to the ADC input. Try 50 to 200 Ohm. This R is to help keep the Op-amp from ‘seeing’ a capacitive load.