portapack-mayhem/firmware/baseband/proc_tpms.cpp
Jared Boone 9f6c495fef Add TPMS initial demodulator implementation.
Right now, 2FSK, 19200 baud, +/-38400Hz deviation. No effort is made to check CRC/checksums or decode packets.
2015-11-10 15:19:56 -08:00

74 lines
2.1 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;
void TPMSProcessor::execute(buffer_c8_t buffer) {
/* 2.4576MHz, 2048 samples */
auto decimator_out = decimator.execute(buffer);
/* 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++) {
// TODO: No idea why implicit cast int16_t->float is not allowed.
const std::complex<float> sample {
static_cast<float>(decimator_out.p[i].real()),
static_cast<float>(decimator_out.p[i].imag())
};
if( mf.execute_once(sample) ) {
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 std::bitset<1024>& payload,
const size_t bits_received
) {
TPMSPacketMessage message;
message.packet.payload = payload;
message.packet.bits_received = bits_received;
shared_memory.application_queue.push(message);
}