kopia lustrzana https://github.com/mobilinkd/tnc3-firmware
46 wiersze
1.3 KiB
C++
46 wiersze
1.3 KiB
C++
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// Copyright 2017 Rob Riggs <rob@mobilinkd.com>
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// All rights reserved.
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#include "AfskDemodulator.hpp"
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namespace mobilinkd { namespace tnc { namespace afsk1200 {
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hdlc::IoFrame* Demodulator::operator()(float* samples, size_t len)
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{
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using namespace mobilinkd::tnc::gpio;
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hdlc::IoFrame* result = 0;
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float* fa = audio_filter_(samples);
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std::transform(fa, fa + audio::ADC_BUFFER_SIZE, buffer_a, agc_);
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auto levels = input_comparator_(buffer_a);
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for (size_t i = 0; i != len; i++) {
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bool delayed = delay_line_(levels[i]);
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float_type x = float_type(levels[i] ^ delayed) - .5f;
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float_type fc = correlator_filter_(x);
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bool bit = output_comparator_(fc);
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auto pll = pll_(bit);
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if (pll.sample) {
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if (locked_ != pll.locked) {
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locked_ = pll.locked;
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}
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// We will only ever get one frame because there are
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// not enough bits in a block for more than one.
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if (result) {
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auto tmp = hdlc_decoder_(nrzi_.decode(bit), pll.locked);
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if (tmp) hdlc::ioFramePool().release(tmp);
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} else {
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result = hdlc_decoder_(nrzi_.decode(bit), pll.locked);
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}
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}
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}
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return result;
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}
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}}} // mobilinkd::tnc::afsk1200
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