fs = 1652 Hz
fc = 208 Hz

def fir_lowpass(data, fc, fs, nfft):

# Convert to normalized frequency
fc_nor = fc / (fs / 2)

N = nfft

n = np.arange(N)

# Compute sinc filter.
h = np.sinc(2 * fc * (n - (N - 1) / 2))

# Compute hanning window.
w = signal.hann(N)

# Multiply sinc filter with window.
h = h * w

# Normalize to get unity gain.
h = h / np.sum(h)

# Apply filter to data
data = np.convolve(data, h, 'same')

return data

def IIR_lowpass(data, fc, fs):

fc_nor = fc / (fs / 2)              # Normalize cutoff frequency

b, a = signal.butter(5, fc_nor, btype='low', analog=False, output='ba')

filt_data = signal.filtfilt(b, a, data)


return filt_data