portapack-mayhem/firmware/baseband/proc_tpms.cpp
2016-01-02 10:42:40 -08:00

99 lines
2.9 KiB
C++

/*
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "proc_tpms.hpp"
#include "portapack_shared_memory.hpp"
#include "i2s.hpp"
using namespace lpc43xx;
#include "dsp_fir_taps.hpp"
static constexpr fir_taps_real<24> taps_200k_decim_0 = {
.pass_frequency_normalized = 100000.0f / 2457600.0f,
.stop_frequency_normalized = 407200.0f / 2457600.0f,
.taps = { {
90, 94, 4, -240, -570, -776, -563, 309,
1861, 3808, 5618, 6710, 6710, 5618, 3808, 1861,
309, -563, -776, -570, -240, 4, 94, 90,
} },
};
static constexpr fir_taps_real<16> taps_200k_decim_1 = {
.pass_frequency_normalized = 100000.0f / 614400.0f,
.stop_frequency_normalized = 207200.0f / 614400.0f,
.taps = { {
-132, -256, 545, 834, -1507, -2401, 4666, 14583,
14583, 4666, -2401, -1507, 834, 545, -256, -132,
} },
};
TPMSProcessor::TPMSProcessor() {
decim_0.configure(taps_200k_decim_0.taps, 33554432);
decim_1.configure(taps_200k_decim_1.taps, 131072);
}
void TPMSProcessor::execute(const buffer_c8_t& buffer) {
/* 2.4576MHz, 2048 samples */
const buffer_c16_t dst_buffer {
dst.data(),
dst.size()
};
const auto decim_0_out = decim_0.execute(buffer, dst_buffer);
const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
const auto decimator_out = decim_1_out;
/* 76.8kHz, 64 samples */
feed_channel_stats(decimator_out);
/* No spectrum display while FSK decoding.
feed_channel_spectrum(
channel,
decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
);
*/
for(size_t i=0; i<decimator_out.count; i++) {
if( mf.execute_once(decimator_out.p[i]) ) {
clock_recovery(mf.get_output());
}
}
i2s::i2s0::tx_mute();
}
void TPMSProcessor::consume_symbol(
const float raw_symbol
) {
const uint_fast8_t sliced_symbol = (raw_symbol >= 0.0f) ? 1 : 0;
packet_builder.execute(sliced_symbol);
}
void TPMSProcessor::payload_handler(
const baseband::Packet& packet
) {
const TPMSPacketMessage message { packet };
shared_memory.application_queue.push(message);
}