portapack-mayhem/firmware/common/ert_packet.cpp
Jared Boone eb1402764e Move ERT packet type to its rightful place.
No longer mixed up with Message types.
2015-12-08 16:19:27 -08:00

97 lines
2.3 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 "ert_packet.hpp"
#include "crc.hpp"
namespace ert {
size_t Packet::length() const {
return decoder_.symbols_count();
}
bool Packet::is_valid() const {
return true;
}
rtc::RTC Packet::received_at() const {
return received_at_;
}
Packet::Type Packet::type() const {
return type_;
}
ID Packet::id() const {
if( type() == Type::SCM ) {
const auto msb = reader_.read(0, 2);
const auto lsb = reader_.read(35, 24);
return (msb << 24) | lsb;
}
if( type() == Type::IDM ) {
return reader_.read(5 * 8, 32);
}
return invalid_id;
}
Consumption Packet::consumption() const {
if( type() == Type::SCM ) {
return reader_.read(11, 24);
}
if( type() == Type::IDM ) {
return reader_.read(25 * 8, 32);
}
return invalid_consumption;
}
ManchesterFormatted Packet::symbols_formatted() const {
return format_manchester(decoder_);
}
bool Packet::crc_ok() const {
switch(type()) {
case Type::SCM: return crc_ok_scm();
case Type::IDM: return crc_ok_idm();
default: return false;
}
}
bool Packet::crc_ok_scm() const {
CRC<uint16_t> ert_bch { 0x6f63 };
size_t start_bit = 5;
ert_bch.process_byte(reader_.read(0, start_bit));
for(size_t i=start_bit; i<length(); i+=8) {
ert_bch.process_byte(reader_.read(i, 8));
}
return ert_bch.checksum() == 0x0000;
}
bool Packet::crc_ok_idm() const {
CRC<uint16_t> ert_crc_ccitt { 0x1021, 0xffff, 0x1d0f };
for(size_t i=0; i<length(); i+=8) {
ert_crc_ccitt.process_byte(reader_.read(i, 8));
}
return ert_crc_ccitt.checksum() == 0x0000;
}
} /* namespace ert */