Exponential-Filter Library for Arduino Arduino Exponential-Filter provides an exponential filter to smooth a "noisy" input data value. OUTPUT[t] = OUTPUT[t-1] + α(INPUT[t] - OUTPUT[t-1]) += α(INPUT[t] - OUTPUT[t-1]) Where: α = ∆t/ (RC + ∆t) When: τ = RC [seconds] = 1 / 2πƒ