kopia lustrzana https://github.com/F5OEO/PiFmRds
83 wiersze
2.3 KiB
Python
Executable File
83 wiersze
2.3 KiB
Python
Executable File
#!/usr/bin/python
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# PiFmRds - FM/RDS transmitter for the Raspberry Pi
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# Copyright (C) 2014 Christophe Jacquet, F8FTK
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#
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# See https://github.com/ChristopheJacquet/PiFmRds
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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# This program generates the waveform of a single biphase symbol
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#
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# This program uses Pydemod, see https://github.com/ChristopheJacquet/Pydemod
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import pydemod.app.rds as rds
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import numpy
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import scipy.io.wavfile as wavfile
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import io
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import matplotlib.pyplot as plt
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sample_rate = 228000
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outc = io.open("waveforms.c", mode="w", encoding="utf8")
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outh = io.open("waveforms.h", mode="w", encoding="utf8")
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header = u"""
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/* This file was automatically generated by "generate_waveforms.py".
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(C) 2014 Christophe Jacquet.
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Released under the GNU GPL v3 license.
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*/
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"""
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outc.write(header)
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outh.write(header)
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def generate_bit(name):
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offset = 240
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l = 96
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count = 2
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sample = numpy.zeros(3*l)
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sample[l] = 1
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sample[2*l] = -1
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# Apply the data-shaping filter
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sf = rds.pulse_shaping_filter(96*8, 228000)
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shapedSamples = numpy.convolve(sample, sf)
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out = shapedSamples[528-288:528+288] #[offset:offset+l*count]
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#plt.plot(sf)
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#plt.plot(out)
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#plt.show()
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iout = (out * 20000./max(abs(out)) ).astype(numpy.dtype('>i2'))
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wavfile.write(u"waveform_{}.wav".format(name), sample_rate, iout)
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outc.write(u"float waveform_{name}[] = {{{values}}};\n\n".format(
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name = name,
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values = u", ".join(map(unicode, out/2.5))))
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# note: need to limit the amplitude so as not to saturate when the biphase
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# waveforms are summed
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outh.write(u"extern float waveform_{name}[{size}];\n".format(name=name, size=len(out)))
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generate_bit("biphase")
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outc.close()
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outh.close() |