TheArchive/mayhem-firmware
1
0
Fork 0
mirror of https://github.com/portapack-mayhem/mayhem-firmware.git synced 2025-01-05 21:07:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

Manchester decoder into separate class.

Browse Source 
Now operates directly on data, doesn't make a new pair of data/error bitsets.
This commit is contained in:
Jared Boone 2015-12-01 12:05:42 -08:00
parent 426295b93e
commit d75f601b54
1 changed files with 46 additions and 39 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

85
firmware/application/ui_receiver.cpp
View File

@ -544,30 +544,60 @@ void ReceiverView::on_packet_ais(const AISPacketMessage& message) {
static FIL fil_tpms; static FIL fil_tpms;
class ManchesterDecoder {
public:
struct DecodedSymbol {
bool value;
bool error;
};
constexpr ManchesterDecoder(
const std::bitset<1024>& encoded,
const size_t count,
const size_t sense = 0
) : encoded { encoded },
count { count },
sense { sense }
{
}
DecodedSymbol operator[](const size_t index) const {
const auto value = encoded[index * 2 + sense];
const auto error = encoded[index * 2 + 0] == encoded[index * 2 + 1];
return { value, error };
}
size_t symbols_count() const {
return count / 2;
}
private:
const std::bitset<1024>& encoded;
const size_t count;
const size_t sense;
};
static std::pair<std::string, std::string> format_manchester( static std::pair<std::string, std::string> format_manchester(
const uint_fast8_t sense, const ManchesterDecoder& decoder
const std::bitset<1024>& payload,
const size_t payload_length
) { ) {
const size_t payload_length_decoded = payload_length / 2; const size_t payload_length_decoded = decoder.symbols_count();
const size_t payload_length_bytes = (payload_length_decoded + 7) / 8; const size_t payload_length_bytes = (payload_length_decoded + 7) / 8;
const size_t payload_length_symbols_rounded = payload_length_bytes * 8 * 2; const size_t payload_length_symbols_rounded = payload_length_bytes * 8;
std::string hex_data; std::string hex_data;
std::string hex_error; std::string hex_error;
uint8_t byte_data = 0; uint8_t byte_data = 0;
uint8_t byte_error = 0; uint8_t byte_error = 0;
for(size_t i=0; i<payload_length_symbols_rounded; i+=2) { for(size_t i=0; i<payload_length_symbols_rounded; i++) {
const auto bit_data = payload[i+sense]; const auto symbol = decoder[i];
const auto bit_error = (payload[i+0] == payload[i+1]);
byte_data <<= 1; byte_data <<= 1;
byte_data |= bit_data ? 1 : 0; byte_data |= symbol.value ? 1 : 0;
byte_error <<= 1; byte_error <<= 1;
byte_error |= bit_error ? 1 : 0; byte_error |= symbol.error ? 1 : 0;
if( ((i >> 1) & 7) == 7 ) { if( (i & 7) == 7 ) {
hex_data += to_string_hex(byte_data, 2); hex_data += to_string_hex(byte_data, 2);
hex_error += to_string_hex(byte_error, 2); hex_error += to_string_hex(byte_error, 2);
} }
@ -577,10 +607,8 @@ static std::pair<std::string, std::string> format_manchester(
} }
void ReceiverView::on_packet_tpms(const TPMSPacketMessage& message) { void ReceiverView::on_packet_tpms(const TPMSPacketMessage& message) {
auto payload = message.packet.payload; const ManchesterDecoder decoder(message.packet.payload, message.packet.bits_received, 1);
auto payload_length = message.packet.bits_received; const auto hex_formatted = format_manchester(decoder);
const auto hex_formatted = format_manchester(1, payload, payload_length);
auto console = reinterpret_cast<Console*>(widget_content.get()); auto console = reinterpret_cast<Console*>(widget_content.get());
console->writeln(hex_formatted.first.substr(0, 240 / 8)); console->writeln(hex_formatted.first.substr(0, 240 / 8));
@ -606,29 +634,6 @@ void ReceiverView::on_packet_tpms(const TPMSPacketMessage& message) {
} }
} }
static std::bitset<512> manchester_decode(
const size_t sense,
const std::bitset<1024>& encoded,
const size_t count
) {
std::bitset<512> result;
for(size_t i=0; i<count; i+=2) {
result[i >> 1] = encoded[i+sense];
}
return result;
}
static std::bitset<512> manchester_errors(
const std::bitset<1024>& encoded,
const size_t count
) {
std::bitset<512> result;
for(size_t i=0; i<count; i+=2) {
result[i >> 1] = (encoded[i+0] == encoded[i+1]);
}
return result;
}
void ReceiverView::on_packet_ert(const ERTPacketMessage& message) { void ReceiverView::on_packet_ert(const ERTPacketMessage& message) {
auto console = reinterpret_cast<Console*>(widget_content.get()); auto console = reinterpret_cast<Console*>(widget_content.get());
@ -639,7 +644,9 @@ void ReceiverView::on_packet_ert(const ERTPacketMessage& message) {
console->writeln("SCM"); console->writeln("SCM");
} }
const auto hex_formatted = format_manchester(0, message.packet.payload, message.packet.bits_received); const ManchesterDecoder decoder(message.packet.payload, message.packet.bits_received);
const auto hex_formatted = format_manchester(decoder);
console->writeln(hex_formatted.first); console->writeln(hex_formatted.first);
console->writeln(hex_formatted.second); console->writeln(hex_formatted.second);
} }