portapack-mayhem/firmware/application/modems.cpp

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/*
* 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 "modems.hpp"
#include "serializer.hpp"
#include "portapack_persistent_memory.hpp"
using namespace portapack;
namespace modems {
void generate_data(const std::string& in_message, uint16_t * out_data) {
serial_format_t serial_format;
uint8_t parity_init, parity, data_bits, bits, bit, cur_byte;
uint16_t ordered_word, bytes;
serial_format = persistent_memory::serial_format();
if (serial_format.parity == ODD)
parity_init = 1;
else
parity_init = 0;
data_bits = serial_format.data_bits;
for (bytes = 0; bytes < in_message.length(); bytes++) {
parity = parity_init;
cur_byte = in_message[bytes];
bit = 0;
if (serial_format.bit_order == MSB_FIRST) {
ordered_word = cur_byte;
for (bits = 0; bits < data_bits; bits++) {
bit = (cur_byte >> bits) & 1; // Get LSB
parity += bit;
}
} else {
ordered_word = 0;
for (bits = 0; bits < data_bits; bits++) {
bit = (cur_byte >> bits) & 1; // Get LSB
parity += bit;
ordered_word |= (bit << ((data_bits - 1) - bits)); // Set MSB
}
}
if (serial_format.parity) {
ordered_word <<= 1;
ordered_word |= (parity & 1);
}
for (bits = 0; bits < serial_format.stop_bits; bits++) {
ordered_word <<= 1;
ordered_word |= 1;
}
out_data[bytes] = ordered_word;
}
out_data[bytes] = 0; // End marker
}
} /* namespace modems */