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encode message data in separate function

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This commit is contained in:
Hendrik Langer 2023-06-20 20:02:14 +02:00
parent 66765511dd
commit e53652fed0
2 changed files with 70 additions and 55 deletions
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123
src/protocols/Pager/Pager.cpp
View file

@ -74,6 +74,73 @@ int16_t PagerClient::transmit(uint8_t* data, size_t len, uint32_t addr, uint8_t
return(PagerClient::transmit(message));
}
int16_t PagerClient::encodeData(uint32_t* buf, uint8_t* data, size_t len, uint8_t encoding) {
// get symbol bit length based on encoding
uint8_t symbolLength = (encoding == RADIOLIB_PAGER_BCD)?4:7;
// calculate the number of 20-bit data blocks
size_t numDataBlocks = (len * symbolLength) / RADIOLIB_PAGER_MESSAGE_BITS_LENGTH;
if((len * symbolLength) % RADIOLIB_PAGER_MESSAGE_BITS_LENGTH > 0) {
numDataBlocks += 1;
}
// write the data as 20-bit code blocks
int8_t remBits = 0;
uint8_t dataPos = 0;
for(uint8_t blockPos = 0; blockPos < numDataBlocks; blockPos++) {
// mark this as a message code word
buf[blockPos] = RADIOLIB_PAGER_MESSAGE_CODE_WORD << (RADIOLIB_PAGER_CODE_WORD_LEN - 1);
// first insert the remainder from previous code word (if any)
if(remBits > 0) {
// this doesn't apply to BCD messages, so no need to check that here
uint8_t prev = Module::reflect(data[dataPos - 1], 8);
prev >>= 1;
buf[blockPos] |= (uint32_t)prev << (RADIOLIB_PAGER_CODE_WORD_LEN - 1 - remBits);
}
// set all message symbols until we overflow to the next code word or run out of message symbols
int8_t symbolPos = RADIOLIB_PAGER_CODE_WORD_LEN - 1 - symbolLength - remBits;
while(symbolPos > (RADIOLIB_PAGER_FUNC_BITS_POS - symbolLength)) {
uint8_t symbol;
if(dataPos < len) {
symbol = data[dataPos++];
} else if(dataPos >= len) {
// we ran out of message symbols
// in BCD mode, pad the rest of the code word with spaces (0xC)
if(encoding == RADIOLIB_PAGER_BCD) {
symbol = ' ';
} else {
break;
}
}
// for BCD, encode the symbol
if(encoding == RADIOLIB_PAGER_BCD) {
symbol = encodeBCD(symbol);
}
symbol = Module::reflect(symbol, 8);
symbol >>= (8 - symbolLength);
// insert the next message symbol
buf[blockPos] |= (uint32_t)symbol << symbolPos;
symbolPos -= symbolLength;
}
// ensure the parity bits are not set due to overflow
buf[blockPos] &= ~(RADIOLIB_PAGER_BCH_BITS_MASK);
// save the number of overflown bits
remBits = RADIOLIB_PAGER_FUNC_BITS_POS - symbolPos - symbolLength;
// do the FEC
buf[blockPos] = RadioLibBCHInstance.encode(buf[blockPos]);
}
return(RADIOLIB_ERR_NONE);
}
int16_t PagerClient::transmit(PagerMessage_t &message) {
uint32_t addr = message.addr;
if(addr > RADIOLIB_PAGER_ADDRESS_MAX) {
@ -158,61 +225,7 @@ int16_t PagerClient::transmit(PagerMessage_t &message) {
// write address code word
msg[framePosAddr] = RadioLibBCHInstance.encode(frameAddr);
// write the data as 20-bit code blocks
int8_t remBits = 0;
uint8_t dataPos = 0;
for(size_t i = 0; i < numDataBlocks; i++) {
uint8_t blockPos = framePosAddr + 1 + i;
// mark this as a message code word
msg[blockPos] = RADIOLIB_PAGER_MESSAGE_CODE_WORD << (RADIOLIB_PAGER_CODE_WORD_LEN - 1);
// first insert the remainder from previous code word (if any)
if(remBits > 0) {
// this doesn't apply to BCD messages, so no need to check that here
uint8_t prev = Module::reflect(data[dataPos - 1], 8);
prev >>= 1;
msg[blockPos] |= (uint32_t)prev << (RADIOLIB_PAGER_CODE_WORD_LEN - 1 - remBits);
}
// set all message symbols until we overflow to the next code word or run out of message symbols
int8_t symbolPos = RADIOLIB_PAGER_CODE_WORD_LEN - 1 - symbolLength - remBits;
while(symbolPos > (RADIOLIB_PAGER_FUNC_BITS_POS - symbolLength)) {
uint8_t symbol;
if(dataPos < len) {
symbol = data[dataPos++];
} else if(dataPos >= len) {
// we ran out of message symbols
// in BCD mode, pad the rest of the code word with spaces (0xC)
if(encoding == RADIOLIB_PAGER_BCD) {
symbol = ' ';
} else {
break;
}
}
// for BCD, encode the symbol
if(encoding == RADIOLIB_PAGER_BCD) {
symbol = encodeBCD(symbol);
}
symbol = Module::reflect(symbol, 8);
symbol >>= (8 - symbolLength);
// insert the next message symbol
msg[blockPos] |= (uint32_t)symbol << symbolPos;
symbolPos -= symbolLength;
}
// ensure the parity bits are not set due to overflow
msg[blockPos] &= ~(RADIOLIB_PAGER_BCH_BITS_MASK);
// save the number of overflown bits
remBits = RADIOLIB_PAGER_FUNC_BITS_POS - symbolPos - symbolLength;
// do the FEC
msg[blockPos] = RadioLibBCHInstance.encode(msg[blockPos]);
}
encodeData(msg+framePosAddr+1, data, len, encoding);
// transmit the preamble
for(size_t i = 0; i < RADIOLIB_PAGER_PREAMBLE_LENGTH; i++) {

2
src/protocols/Pager/Pager.h
View file

@ -158,6 +158,8 @@ class PagerClient {
*/
int16_t transmit(PagerMessage_t &message);
int16_t encodeData(uint32_t* buf, uint8_t* data, size_t len, uint8_t encoding);
#if !defined(RADIOLIB_EXCLUDE_DIRECT_RECEIVE)
/*!
\brief Start reception of POCSAG packets.