mirror of
https://github.com/g4klx/MMDVM_HS.git
synced 2025-12-06 07:02:00 +01:00
Clean up the M17 synchronisation.
This commit is contained in:
Jonathan Naylor
parent
4f1ed20d77
commit
2f52282c47
38
M17RX.cpp
38
M17RX.cpp
|
|
@ -25,7 +25,7 @@
|
|||
const uint8_t MAX_SYNC_BIT_START_ERRS = 0U;
|
||||
const uint8_t MAX_SYNC_BIT_RUN_ERRS = 2U;
|
||||
|
||||
const unsigned int MAX_SYNC_FRAMES = 5U + 1U;
|
||||
const unsigned int MAX_SYNC_FRAMES = 3U + 1U;
|
||||
|
||||
const uint8_t BIT_MASK_TABLE[] = {0x80U, 0x40U, 0x20U, 0x10U, 0x08U, 0x04U, 0x02U, 0x01U};
|
||||
|
||||
|
|
@ -53,17 +53,17 @@ void CM17RX::reset()
|
|||
void CM17RX::databit(bool bit)
|
||||
{
|
||||
switch (m_state) {
|
||||
case M17RXS_NONE:
|
||||
processNone(bit);
|
||||
case M17RXS_LINK_SETUP:
|
||||
processLinkSetup(bit);
|
||||
break;
|
||||
case M17RXS_HEADER:
|
||||
processHeader(bit);
|
||||
case M17RXS_STREAM:
|
||||
processStream(bit);
|
||||
break;
|
||||
case M17RXS_PACKET:
|
||||
processPacket(bit);
|
||||
break;
|
||||
default:
|
||||
processStream(bit);
|
||||
processNone(bit);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
|
@ -74,15 +74,15 @@ void CM17RX::processNone(bool bit)
|
|||
if (bit)
|
||||
m_bitBuffer |= 0x01U;
|
||||
|
||||
// Fuzzy matching of the header sync bit sequence
|
||||
// Fuzzy matching of the link setup sync bit sequence
|
||||
if (countBits16(m_bitBuffer ^ M17_LINK_SETUP_SYNC_BITS) <= MAX_SYNC_BIT_START_ERRS) {
|
||||
DEBUG1("M17RX: header sync found in None");
|
||||
DEBUG1("M17RX: link setup sync found in None");
|
||||
for (uint8_t i = 0U; i < M17_SYNC_BYTES_LENGTH; i++)
|
||||
m_buffer[i] = M17_LINK_SETUP_SYNC_BYTES[i];
|
||||
|
||||
m_lostCount = MAX_SYNC_FRAMES;
|
||||
m_bufferPtr = M17_SYNC_LENGTH_BITS;
|
||||
m_state = M17RXS_HEADER;
|
||||
m_state = M17RXS_LINK_SETUP;
|
||||
|
||||
io.setDecode(true);
|
||||
}
|
||||
|
|
@ -114,7 +114,7 @@ void CM17RX::processNone(bool bit)
|
|||
}
|
||||
}
|
||||
|
||||
void CM17RX::processHeader(bool bit)
|
||||
void CM17RX::processLinkSetup(bool bit)
|
||||
{
|
||||
m_bitBuffer <<= 1;
|
||||
if (bit)
|
||||
|
|
@ -126,16 +126,6 @@ void CM17RX::processHeader(bool bit)
|
|||
if (m_bufferPtr > M17_FRAME_LENGTH_BITS)
|
||||
reset();
|
||||
|
||||
// Only search for a sync in the right place +-2 symbols
|
||||
if (m_bufferPtr >= (M17_SYNC_LENGTH_BITS - 2U) && m_bufferPtr <= (M17_SYNC_LENGTH_BITS + 2U)) {
|
||||
// Fuzzy matching of the data sync bit sequence
|
||||
if (countBits16(m_bitBuffer ^ M17_LINK_SETUP_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
|
||||
DEBUG2("M17RX: found header sync in Data, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
|
||||
m_lostCount = MAX_SYNC_FRAMES;
|
||||
m_bufferPtr = M17_SYNC_LENGTH_BITS;
|
||||
}
|
||||
}
|
||||
|
||||
// Send a data frame to the host if the required number of bits have been received
|
||||
if (m_bufferPtr == M17_FRAME_LENGTH_BITS) {
|
||||
m_lostCount--;
|
||||
|
|
@ -145,9 +135,7 @@ void CM17RX::processHeader(bool bit)
|
|||
writeRSSIHeader(m_outBuffer);
|
||||
|
||||
// Start the next frame, but we don't know the type
|
||||
::memset(m_outBuffer, 0x00U, M17_FRAME_LENGTH_BYTES + 3U);
|
||||
m_state = M17RXS_NONE;
|
||||
m_bufferPtr = 0U;
|
||||
reset();
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -167,7 +155,7 @@ void CM17RX::processStream(bool bit)
|
|||
if (m_bufferPtr >= (M17_SYNC_LENGTH_BITS - 2U) && m_bufferPtr <= (M17_SYNC_LENGTH_BITS + 2U)) {
|
||||
// Fuzzy matching of the stream sync bit sequence
|
||||
if (countBits16(m_bitBuffer ^ M17_STREAM_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
|
||||
DEBUG2("M17RX: found stream sync in Data, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
|
||||
DEBUG2("M17RX: found stream sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
|
||||
m_lostCount = MAX_SYNC_FRAMES;
|
||||
m_bufferPtr = M17_SYNC_LENGTH_BITS;
|
||||
}
|
||||
|
|
@ -211,7 +199,7 @@ void CM17RX::processPacket(bool bit)
|
|||
if (m_bufferPtr >= (M17_SYNC_LENGTH_BITS - 2U) && m_bufferPtr <= (M17_SYNC_LENGTH_BITS + 2U)) {
|
||||
// Fuzzy matching of the packet sync bit sequence
|
||||
if (countBits16(m_bitBuffer ^ M17_PACKET_SYNC_BITS) <= MAX_SYNC_BIT_RUN_ERRS) {
|
||||
DEBUG2("M17RX: found packet sync in Data, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
|
||||
DEBUG2("M17RX: found packet sync, pos", m_bufferPtr - M17_SYNC_LENGTH_BITS);
|
||||
m_lostCount = MAX_SYNC_FRAMES;
|
||||
m_bufferPtr = M17_SYNC_LENGTH_BITS;
|
||||
}
|
||||
|
|
|
|||
4
M17RX.h
4
M17RX.h
|
|
@ -24,7 +24,7 @@
|
|||
|
||||
enum M17RX_STATE {
|
||||
M17RXS_NONE,
|
||||
M17RXS_HEADER,
|
||||
M17RXS_LINK_SETUP,
|
||||
M17RXS_STREAM,
|
||||
M17RXS_PACKET
|
||||
};
|
||||
|
|
@ -46,7 +46,7 @@ private:
|
|||
uint16_t m_lostCount;
|
||||
|
||||
void processNone(bool bit);
|
||||
void processHeader(bool bit);
|
||||
void processLinkSetup(bool bit);
|
||||
void processStream(bool bit);
|
||||
void processPacket(bool bit);
|
||||
void writeRSSIHeader(uint8_t* data);
|
||||
|
|
|
|||
Loading…
Reference in a new issue