I’ve placed constant weights on the force sensor (R_flexiforce) in my circuit (diagram attached, recommended by the sensor manufacturer) and always measure a fluctuation of +/- 15 Arduino output units (about 0.1V). This also occurs without any weight on the sensor, which has a resistance of 5 M ohms in that case. The fluctuation is very consistent, with the same range of +/- 15 and frequency of about 0.2 Hz (12 cycles per minute).
Currently C1 = 22 pF and Vref = 0.27 V. The Arduino pins I’m using are and 5V, GND, and A0. My code currently records at a delay of 100ms and outputs an average of the past 10 readings, and I’ve observed the same fluctuation with both smaller and larger delays and no averaging.
I’ve searched this issue on Google and this forum and read through the three below links with similar issues. They mentioned using input from the wall instead of the Arduino as well as a capacitor across AREF, but I’m not sure how to interpret that in the context of my situation.
Thank you, I appreciate your time!