mirror of
https://github.com/eried/portapack-mayhem.git
synced 2024-12-27 00:09:36 -05:00
77 lines
2.1 KiB
C++
77 lines
2.1 KiB
C++
/*
|
|
* Copyright (C) 2017 Jared Boone, ShareBrained Technology, Inc.
|
|
* Copyright (C) 2019 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 "rfm69.hpp"
|
|
#include "crc.hpp"
|
|
#include "portapack_shared_memory.hpp"
|
|
|
|
uint32_t RFM69::gen_frame(std::vector<uint8_t>& payload) {
|
|
CRC<16> crc { 0x1021, 0x1D0F, 0xFFFF };
|
|
std::vector<uint8_t> frame { };
|
|
uint8_t byte_out = 0;
|
|
|
|
// Preamble
|
|
// Really is 0xAA but the RFM69 skips the very last bit (bug ?)
|
|
// so the whole preamble is shifted right to simulate that
|
|
frame.insert(frame.begin(), num_preamble_, 0x55);
|
|
|
|
// Sync word
|
|
frame.push_back(sync_word_ >> 8);
|
|
frame.push_back(sync_word_ & 0xFF);
|
|
|
|
// Payload length
|
|
payload.insert(payload.begin(), payload.size());
|
|
|
|
crc.process_bytes(payload.data(), payload.size());
|
|
|
|
if (CRC_) {
|
|
payload.push_back(crc.checksum() >> 8);
|
|
payload.push_back(crc.checksum() & 0xFF);
|
|
}
|
|
|
|
// Manchester-encode payload
|
|
if (manchester_) {
|
|
for (auto byte : payload) {
|
|
for (uint32_t b = 0; b < 8; b++) {
|
|
byte_out <<= 2;
|
|
|
|
if (byte & 0x80)
|
|
byte_out |= 0b10;
|
|
else
|
|
byte_out |= 0b01;
|
|
|
|
if ((b & 3) == 3)
|
|
frame.push_back(byte_out);
|
|
|
|
byte <<= 1;
|
|
}
|
|
}
|
|
} else {
|
|
frame.insert(frame.end(), payload.begin(), payload.end());
|
|
}
|
|
|
|
memcpy(shared_memory.bb_data.data, frame.data(), frame.size());
|
|
|
|
// Copy for baseband
|
|
return frame.size();
|
|
}
|