inaccurate value from sensor A201 (using inverting Op-Amp)

HI everyone.
I need help in Arduino Uno coding for this Flexiforce(A201) inverting Op-Amp circuit.

Flexiforce analog reading was 772 max if I used 100k ohm as feedback.
input for the sensor (-5V).

FlexiforceReading = analogread * (5.0/ 772.0);

need to get the value of load applied.

Thank You.


The suggested circuit for the flexiforce sensor indicates the negative rail for the sensor should be
in the range -0.25 to -1.25V DC.

You are using -9V, so its entirely possible you may have fried the sensor.

You are missing the 47pF stability cap too, so your circuit may be oscillating at high frequency
which would show up as erroneous readings and unstable behaviour.

thank you so much, sir. the attached picture is the datasheet that I followed. it shows (Vt = - 5V).
and I just noticed there are another datasheet for A201 but stated (Vt =-1V).
I have checked my sensors. luckily it’s still working.
and I have tried to change the voltage to -1V just to obtain the reading. buts its not working at all.
I’m not sure where I go wrong.