I am trying to measure the resistance of a nichrome wire that has a PWM (1000Hz and different duty cycles between 0 and 100%) voltage applied to it from a 5.0V regulator. The setup I have in mind looks like this:
5V PWM ---- Wire (~20 Ohm) ----X---- 1W Resistor (0.5 Ohm) --- Ground
I then measure the voltage at point labeled X with respect to ground, and amplify it using an instrumentation amplifier (TI INA122). As the nichrome wire is heating, I want to obtain its temperature by measuring its change in resistance which would correspond to change in measured voltage given by my amplifier. However, I expect noise so I want to filter it out. I don't know to go about doing this since the signal is PWM. If it was straight up DC then I'd use a low pass filter, but now I am stuck.
Here is a picture of what I'm trying to accomplish. Basically smooth out the noise like shown.
Thank you in advance!