FlexiForce Pressure Sensor

Using Arduino Sensors
1

Has anyone had any success hooking up the FlexiForce 100lb Pressure Sensor to the Arduino? This is what we have done:

We hooked up the the left pin to the 5V, the middle pin to ground, and the right pin to A0. This is the only setup that gives us a reading. Our problem is that when we slightly press on the pressure sensor, the serial monitor shows the maximum, 1023!

The schematic is here. Embedded Force Sensors | Tekscan

Are we required to use an opamp or is there some kind of code that can replace the opamp?

Thank you to anyone who points us in the right direction.

2

Yes, you need a op-amp circuit to output a usable DC signal for a Arduino analog input pin. Below is their recommended 'conditioning/calibrating' circuit.

It's a pain to have to come up with that negative 1 volt for the sensor and calibrating the feedback resistor looks to be a pain. It's an interesting sensor, but they sure didn't make it very user friendly for interfacing.

http://www.tekscan.com/flexiforce-sample-circuit

Lefty

3

How would I go about creating this negative voltage? At first I was thinking that I could just use an inverting op-amp with a 1/5 gain...

But then I realized that the Vcc's need a +10 and -10 volts... So how to I create a negative voltage when the op-amp requires a negative voltage...?

4

What is the code you are using?