mayhem-firmware/firmware/baseband/proc_adsbtx.cpp
2017-05-25 21:08:33 +01:00

116 lines
2.7 KiB
C++

/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
* Copyright (C) 2016 Furrtek
*
* 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_adsbtx.hpp"
#include "portapack_shared_memory.hpp"
#include "sine_table_int8.hpp"
#include "event_m4.hpp"
#include <cstdint>
void ADSBTXProcessor::execute(const buffer_c8_t& buffer) {
// This is called at 4M/2048 = 1953Hz
// One pulse = 500ns = 2 samples
// One bit = 2 pulses = 1us = 4 samples
if (!configured) return;
for (size_t i = 0; i < buffer.count; i++) {
if (active) {
if (!sample) {
sample = 3;
if (preamble) {
if (bit_pos >= 16) {
preamble = false;
bit_pos = 0;
} else {
cur_bit = (preamble_parts << bit_pos) >> 15;
bit_pos++;
}
}
if (!preamble) {
if (bit_pos >= 112) {
active = false; // Stop
cur_bit = 0;
} else {
cur_bit = shared_memory.bb_data.data[bit_pos];
bit_pos++;
}
}
} else
sample--;
if (sample == 1)
cur_bit ^= 1; // Invert
} else {
//cur_bit = 0;
if (bit_pos == 8192) { // ?
configured = false;
message.done = true;
shared_memory.application_queue.push(message);
}
bit_pos++;
}
delta = tone_sample * fm_delta;
tone_sample += 128;
if (cur_bit) {
phase += delta;
sphase = phase + (64 << 24);
re = (sine_table_i8[(sphase & 0xFF000000U) >> 24]);
im = (sine_table_i8[(phase & 0xFF000000U) >> 24]);
} else {
re = 0;
im = 0;
}
buffer.p[i] = {re, im};
}
}
void ADSBTXProcessor::on_message(const Message* const p) {
const auto message = *reinterpret_cast<const ADSBConfigureMessage*>(p);
if (message.id == Message::ID::ADSBConfigure) {
bit_pos = 0;
sample = 0;
cur_bit = 0;
preamble = true;
active = true;
configured = true;
fm_delta = 50000 * (0xFFFFFFULL / 4000000); // Fixed bw for now
}
}
int main() {
EventDispatcher event_dispatcher { std::make_unique<ADSBTXProcessor>() };
event_dispatcher.run();
return 0;
}