Example Python script to implement the FIR Filter Box

# pymoku example: Basic FIR Filter Box
# 
# This example demonstrates how to run the FIR Filter Box and configure its
# individual filter channel coefficients.
# 
# (c) 2019 Liquid Instruments Pty. Ltd.
#

from pymoku import Moku
from pymoku.instruments import FIRFilter

# The following two example arrays are simple rectangular FIR kernels with 50
# and 400 taps respectively. A rectangular kernel produces a sinc shaped
# transfer function with width inversely proportional to the length of the
# kernel. FIR kernels must have a normalised power of <= 1.0, so the value of
# each tap is the inverse of the total number of taps.
filt_coeff1 = [1.0 / 50.0] * 50
filt_coeff2 = [1.0 / 400.0] * 400

# Connect to your Moku by its device name
# Alternatively, use Moku.get_by_serial('#####') or Moku('192.168.###.###')
m = Moku.get_by_name('Moku')

try:
 i = m.deploy_or_connect(FIRFilter)

 # Configure the Moku:Lab's frontend settings
 i.set_frontend(1, fiftyr=True, atten=False, ac=False)
 i.set_frontend(2, fiftyr=True, atten=False, ac=False)

 # Load the coefficients for each FIR filter channel.
 #
 # The channel's decimation factor determines the filter sample rate (Fs)
 # and the maximum number of filter kernel coefficients (N) for the channel.
 # The defining equations are given by:
 #
 # 3 <= decimation_factor <= 10,
 # Fs = 125 MHz / 2^decimation_factor,
 # N = 2^(decimation_factor) * 29.
 #
 # To implement 50 FIR taps, N = 2^(3) * 29 = 232 > 50
 i.set_filter(1, decimation_factor=3, filter_coefficients=filt_coeff1)
 # To implement 400 FIR taps, N = 2^(4) * 29 = 464 > 400
 i.set_filter(2, decimation_factor=4, filter_coefficients=filt_coeff2)

 # Both channels have unity gain and no offsets
 i.set_gains_offsets(1, input_gain=1.0, output_gain=1.0, input_offset=0,
 output_offset=0)
 i.set_gains_offsets(2, input_gain=1.0, output_gain=1.0, input_offset=0,
 output_offset=0)

finally:
 m.close()