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https://github.com/romanz/amodem.git
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73 lines
1.6 KiB
Python
73 lines
1.6 KiB
Python
from matplotlib import pyplot as plt
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import subprocess as sp
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import numpy as np
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import os
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import sys
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import time
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import signal
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import logging
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logging.basicConfig(level=0, format='%(message)s')
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log = logging.getLogger(__name__)
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import sigproc
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from common import *
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def play(fd):
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args = ['aplay', fd.name, '-f', 'S16_LE', '-c', '1', '-r', str(int(Fs))]
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ret = sp.call(args=args)
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assert ret == 0
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def record(fname):
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args = ['arecord', fname, '-f', 'S16_LE', '-c', '1', '-r', str(int(Fs))]
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p = sp.Popen(args=args)
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p.stop = lambda: os.kill(r.pid, signal.SIGINT)
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return p
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log.info('MODEM Fc={}KHz, {} BAUD'.format(Fc/1e3, baud))
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class Symbol(object):
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t = np.arange(0, Nsym) * Ts
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# c0 = np.sin(2 * np.pi * F0 * t)
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# c1 = np.sin(2 * np.pi * F1 * t)
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carrier = np.exp(2j * np.pi * Fc * t)
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class Signal(object):
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def __init__(self, fd):
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self.fd = fd
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def send(self, sym, n=1):
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sym = sym.imag * scaling
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sym = sym.astype('int16')
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for i in range(n):
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sym.tofile(fd)
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sym = Symbol()
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data = open('data.send', 'r').read()
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data = pack(data)
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bits = list(to_bits(data))
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if __name__ == '__main__':
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with open('tx.int16', 'wb') as fd:
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sig = Signal(fd)
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sig.send(sym.carrier*0, n=100)
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sig.send(sym.carrier*1, n=300)
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sig.send(sym.carrier*0, n=100)
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for i in range(20):
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sig.send(sym.carrier*1, n=10)
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sig.send(sym.carrier*0, n=10)
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sig.send(sym.carrier*0, n=100)
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for s in sigproc.qpsk.encode(bits):
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sig.send(sym.carrier * s)
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r = record('rx.int16')
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p = play(fd)
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time.sleep(0.2)
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r.stop()
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