Im trying to do a project that requires measurement of a voltage across a resistor in a voltage divider network. I tried the circuit below, but i wasnt able to get correct output. I have a 2.8Vdc across a resistor, Vr, but the output was different. I got a .7V output.

I am only limited to a single supply voltage for the opamp. I used a LM358 opamp and I adapted the circuit from the datasheet of LM358.

Is it really necessary to have a dual supply for the opamp??
Is there any other circuit I can use for this purpose??
help!!!!!!!!!!

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No, but you do need to generate a split rail - as it is you're referencing to the negative supply rail. Using a split supply rail will mean that the output will vary around that voltage, presumably half the supply rail.

Also, as you don't show the rest of the circuit, it's hard to know what other connections there are that could affect things - assuming the opamp is using the same supply?.

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What is the max common mode voltage for your circuit (Vcm)? What are you using for the positive supply rail of the op amp?

Does the current through your Rsense resistor ever reverse direction?