Subversion Repositories cascaded_fir_filter

import matplotlib.pyplot

import numpy

import math

out_file_samp = open("IQ_tone_signal.txt", "w")

out_file_ping = open("IQ_tone_ping.txt", "w")

samp_rate = 50000               # Hz

data_duration = 0.05    # s

tone_freq = 5000                # Hz

ping_duration = 0.002   # s

ping_amplitude = 15

echo_position = 0.025   # s

echo_amplitude = 10

time_acc = 0

time_delta = 1.0 / samp_rate

tone_omega = 2.0 * math.pi * 5000

ping_length = 0

data_length = 0

samps_t = []

samps_I = []

samps_Q = []

pings_t = []

pings_I = []

pings_Q = []

samp_I = 0

samp_Q = 0

while time_acc < data_duration :

        if time_acc < ping_duration :

                samp_I = ping_amplitude * math.cos(tone_omega * time_acc)

                samp_Q = ping_amplitude * math.sin(tone_omega * time_acc)

                pings_t.append(time_acc);

                pings_I.append(samp_I);

                pings_Q.append(samp_Q);

                out_file_ping.write("{0:04x}\r\n{1:04x}\r\n".format(int(samp_I) & 0xFFFF, int(samp_Q) & 0xFFFF))

                ping_length += 1

        else :

                if (time_acc >= echo_position) and (time_acc < echo_position + ping_duration) :

                        samp_I = echo_amplitude * math.cos(tone_omega * time_acc)

                        samp_Q = echo_amplitude * math.sin(tone_omega * time_acc)

                else :

                        samp_I = 0

                        samp_Q = 0

        samps_t.append(time_acc);

        samps_I.append(samp_I);

        samps_Q.append(samp_Q);

        out_file_samp.write("{0:04x}\r\n{1:04x}\r\n".format(int(samp_I) & 0xFFFF, int(samp_Q) & 0xFFFF))

        data_length += 1

        time_acc += time_delta

out_file_ping.close()

out_file_samp.close()

print "ping length = ", ping_length

print "data length = ", data_length

matplotlib.pyplot.figure(1)

matplotlib.pyplot.subplot(3,1,1)

matplotlib.pyplot.plot(samps_t, samps_I)

matplotlib.pyplot.plot(samps_t, samps_Q)

#matplotlib.pyplot.figure(2)

matplotlib.pyplot.subplot(3,1,2)

matplotlib.pyplot.plot(pings_t, pings_I)

matplotlib.pyplot.plot(pings_t, pings_Q)

matplotlib.pyplot.show()