Implementing FIR Bandpass Filter for 1-3Hz range

Okay, thank you for catching that error.

I did have an offset but, also tested a couple times without. Luckily, nothing was damaged.

For the low pass filter with a cut off of 4Hz, would the low pass filter need to be an analog filter from the sensor to the arduino?

And could I simply add a delay(125) to set the code to sample at 8Hz?