SparkFun Forums 

Where electronics enthusiasts find answers.

Questions &/or issues related to products in the Flex / Force category should be posted in this forum. includes Force Sensitive Resistors, Load Cells & Amplifiers, Pressure Sensors, etc
User avatar
By Jackie852
Hello, I am working on the FlexiForce® A401 25lbs and Arduino to measure pressure. Have anyone got an Arduino code work for this sensor?

The code I used is from here: ... okup-guide but it seems the relationship between the conductance and force in this code is not for this A401 sensor, because in my test, the force it read is not the force I applied to it (I put a 300g block on it but it reads 0.9 to 1.2 g). I saw a graph in the product datasheet for the voltage as a function of force but the relationship can only be roughly estimated based on the graph. I would appreciate if anyone can give some advice on this. Thanks.
User avatar
By TS-Mark
Hi Jackie852,

The example code in that guide estimates the force applied using the graphs for the four Force Sensitive Resistors listed in the link here. The FlexiForce sensors work the same as these four but with a different force curve so you would need to adjust the code to try and make it work with the A401. Otherwise, you may need to create your own data points using a standard analogRead sketch and measure the resistance with known weight values. You'll probably also want to play around with different resistor values for your static resistor. Finally, the FlexiForce User Manual has some more detail on these sensors than the datasheet to help you either adjust the example code from our guide or to create your own code.