I am trying to calculate the resolution of my simple force sensor system in Newton [N].
The sensor system consists of a simple voltage divider, where the voltage across the FSR is measured by an 8-bit ADC.
I have calibrated it using a force push-pull gauge, in increments of 1 N in a range from 1-10N, noting down the ADC output, see table.
According to this link, the resolution would be calculated as follows:
Resolution = (V_ref * FS_input) / (V_fso * ADC_resolution)
Looking at the graph, ignoring the fact that my transfer function is non-linear and thus the sensitivity degrades with higher forces and thus the resolution with it, the theoretical resolution of my system assuming a linear voltage change to force input, would be:
FS_input = 10N-1N = 9N ---> because i measured from 1-10 Newtons [N]
V_fso = 2.462V - 1.702V = 0.76V ---> this is the output voltage [V] range for the input force range of 1-10 Newtons [N]
V_ref = 3.3V ---> this is the ADC reference voltage and the voltage across the whole voltage divider
ADC_resolution = 2^n = 2^8 = 256
Resolution = (3.3V * 9N) / (0.76V * 256) = 0.153 N
Meaning the smallest detectable change in force [N] with my 8-bit ADC would be 0.153N.
Is this the correct way to calculate the resolution?