gqrxUdp3.py

import socket
import numpy as np
import matplotlib.pyplot as plt

CHUNK = 1000
NMAX = 20
x  = range   (CHUNK)
y  = np.zeros(CHUNK)
xpnt = 0
n = 0

fig1 = plt.figure(1, figsize=(8, 8))
fig1.subplots_adjust(hspace=0.7, wspace=0.1)

ax1  = fig1.add_subplot(1,1,1)
ax1.set_xlim(0, CHUNK)
ax1.set_ylim(-30000, 30000)
ax1.grid(color='gray', linestyle='dashed', linewidth=1)
lines1, = plt.plot(x, y, color="green")
plt.title('input signal')

UDP_IP = "127.0.0.1"
UDP_PORT = 7355

sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
sock.bind((UDP_IP, UDP_PORT))

while True:
    data, addr = sock.recvfrom(512)
    ldata = len(data)
    for i in range(ldata//2):
        d0 = data[0+2*i]
        d1 = data[1+2*i]
        d2 = d1*256 + d0
        if d1 > 127:
            d2 -= 65536
        y[xpnt] = d2
        xpnt += 1
        if xpnt >= CHUNK:
            xpnt = 0
            n += 1
            if n == NMAX:
                lines1.set_data(x, y)
                plt.pause(0.01)
                n = 0