mirror of
https://github.com/romanz/amodem.git
synced 2026-02-07 09:28:02 +08:00
83 lines
2.0 KiB
Python
83 lines
2.0 KiB
Python
from matplotlib import pyplot as plt
|
|
import subprocess as sp
|
|
import numpy as np
|
|
|
|
import os
|
|
import sys
|
|
import time
|
|
import signal
|
|
import logging
|
|
import itertools
|
|
|
|
logging.basicConfig(level=0, format='%(message)s')
|
|
log = logging.getLogger(__name__)
|
|
|
|
import sigproc
|
|
from common import *
|
|
|
|
dev_null = open('/dev/null')
|
|
|
|
def play(fd):
|
|
args = ['aplay', fd.name, '-q', '-f', 'S16_LE', '-c', '1', '-r', str(int(Fs))]
|
|
ret = sp.call(args=args)
|
|
assert ret == 0
|
|
|
|
def record(fname):
|
|
args = ['arecord', fname, '-q', '-f', 'S16_LE', '-c', '1', '-r', str(int(Fs))]
|
|
p = sp.Popen(args=args)
|
|
p.stop = lambda: os.kill(r.pid, signal.SIGINT)
|
|
return p
|
|
|
|
|
|
class Symbol(object):
|
|
t = np.arange(0, Nsym) * Ts
|
|
carrier = [ np.exp(2j * np.pi * F * t) for F in frequencies ]
|
|
|
|
sym = Symbol()
|
|
|
|
data = open('data.send', 'r').read()
|
|
|
|
def start(sig, c):
|
|
sig.send(c*0, n=100)
|
|
sig.send(c*1, n=300)
|
|
sig.send(c*0, n=100)
|
|
|
|
def train(sig, c):
|
|
for i in range(20):
|
|
sig.send(c*1, n=10)
|
|
sig.send(c*0, n=10)
|
|
sig.send(c*0, n=100)
|
|
|
|
def modulate(sig, bits):
|
|
symbols_iter = sigproc.modulator.encode(list(bits))
|
|
symbols_iter = itertools.chain(symbols_iter, itertools.repeat(0))
|
|
carriers = np.array(sym.carrier) / len(sym.carrier)
|
|
while True:
|
|
symbols = itertools.islice(symbols_iter, len(sym.carrier))
|
|
symbols = np.array(list(symbols))
|
|
sig.send(np.dot(symbols, carriers))
|
|
if all(symbols == 0):
|
|
break
|
|
|
|
if __name__ == '__main__':
|
|
|
|
bps = baud * sigproc.modulator.bits_per_symbol * len(sym.carrier)
|
|
log.info('Running MODEM @ {:.1f} kbps'.format(bps / 1e3))
|
|
|
|
with open('tx.int16', 'wb') as fd:
|
|
sig = Signal(fd)
|
|
start(sig, sym.carrier[carrier_index])
|
|
for c in sym.carrier:
|
|
train(sig, c)
|
|
|
|
bits = to_bits(pack(data))
|
|
modulate(sig, bits)
|
|
|
|
|
|
r = record('rx.int16')
|
|
start = time.time()
|
|
p = play(fd)
|
|
log.debug('Took %.2f seconds', time.time() - start)
|
|
time.sleep(0.1)
|
|
r.stop()
|