So, I’m doing a project using the flexiforce A401 sensor from TekScan and I’m having some trouble setting it up. I’ve looked up on their website, and I found a PDF that explains the 3 types of circuits I can build: inverting op-amp, non-inverting op-amp and the simple voltage divider.
I’ve tried the simple voltage divider first, and the results were pretty good. I created a simple Arduino code and I was able to retrieve normal values from pressing the sensor.
The problem is that, I’ve tried to use the recommended circuit TekScan has for the non-inverting op-amp, and the results make no sense. I’m doing a simple analogRead and I’m getting around 500, when I’m not even touching the sensor. And if I do touch it, the value comes down, when it was supposed to go up.
They recommend the use of the MCP6004 op-amp, but as I didn’t manage to get that one, I’m using the TL074CN.
What do you think it may be causing this circuit to not work? I’ll leave the circuit and the results and I was getting with it here: