# Better way to measure sensors with more Resolution points?

Hello,

I’ve been wanting to measure some sensors like the bend sensor or a LDR with the arduino but there is a problem of getting the full range of the sensor wanted values to the arduino.

It is possible to over come this with a Wheatstone bridge (What they use to measure load cells) but it’s too complicated and it requires additional fine tuning calibration.

So I came across the Differential amplification method where you “Focus” more on the range of what you want to measure(Say resistance of 10K to 18KOhm) by subtracting the lowest voltage(Using a voltage divider in series with the resistor) of the range and amplify it to the highest but figured out this is also not that practical and you can’t fully zero out the results.

Is there any better practical way to do that with no calibration and no more than one additional ic?

If you are using the ADC on a standard Arduino, then you are limited to 1024 possible values. Those 1024 values can be distributed over a wide range of voltages by changing the voltage reference (e.g. internal, for 0 to about 1.1V).

Any external circuit that you add will, in general, add some error and require calibration.

jremington:
If you are using the ADC on a standard Arduino, then you are limited to 1024 possible values. Those 1024 values can be distributed over a wide range of voltages by changing the voltage reference (e.g. internal, for 0 to about 1.1V).

Any external circuit that you add will, in general, add some error and require calibration.

Yes, but I'm trying to spread the the certain voltage range across Analog 0V to Analog Vref so I'll be able to read it more accurately that's why I tried using the method of subtraction and amplification to do it but it's not that practical and It wouldn't require calibration if the resistors at the Differential amplifier circuit wouldn't have to be the same value in order to achieve the simplified equation of Vout = A(V2-V1) which if A = 1 it is Vout = V2 - V1 ( I also would of want to amplify it in the same circuit but the math would be too complicated so I just leave it as A = 1 and amplify it with another op-amp circuit)