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more work on debugging the pager decoder

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AlexandreRouma
2024-02-02 22:52:19 +01:00
parent 7ab743d05b
commit a08d2a0f85
4 changed files with 91 additions and 18 deletions
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77
decoder_modules/pager_decoder/src/pocsag/pocsag.cpp
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@ -5,6 +5,7 @@
#define POCSAG_FRAME_SYNC_CODEWORD ((uint32_t)(0b01111100110100100001010111011000))
#define POCSAG_IDLE_CODEWORD_DATA ((uint32_t)(0b011110101100100111000))
#define POCSAG_BATCH_BIT_COUNT (POCSAG_BATCH_CODEWORD_COUNT*32)
#define POCSAG_DATA_BITS_PER_CW 20
#define POCSAG_GEN_POLY ((uint32_t)(0b11101101001))
@ -28,6 +29,11 @@ namespace pocsag {
'['
};
Decoder::Decoder() {
// Zero out batch
memset(batch, 0, sizeof(batch));
}
void Decoder::process(uint8_t* symbols, int count) {
for (int i = 0; i < count; i++) {
// Get symbol
@ -78,8 +84,37 @@ namespace pocsag {
void Decoder::flushMessage() {
if (!msg.empty()) {
onMessage(addr, msgType, msg);
// Unpack bits
std::string outStr = "";
for (int i = 0; (i+7) <= msg.size(); i += 7) {
uint8_t b0 = msg[i];
uint8_t b1 = msg[i+1];
uint8_t b2 = msg[i+2];
uint8_t b3 = msg[i+3];
uint8_t b4 = msg[i+4];
uint8_t b5 = msg[i+5];
uint8_t b6 = msg[i+6];
outStr += (char)((b6<<6) | (b5<<5) | (b4<<4) | (b3<<3) | (b2<<2) | (b1<<1) | b0);
}
onMessage(addr, msgType, outStr);
msg.clear();
leftInLast = 0;
}
}
void printbin(uint32_t cw) {
for (int i = 31; i >= 0; i--) {
printf("%c", ((cw >> i) & 1) ? '1':'0');
}
}
void bitswapChar(char in, char& out) {
out = 0;
for (int i = 0; i < 7; i++) {
out |= ((in >> (6-i)) & 1) << i;
}
}
@ -102,14 +137,14 @@ namespace pocsag {
if (type == CODEWORD_TYPE_IDLE) {
// If a non-empty message is available, send it out and clear
flushMessage();
flog::debug("[{}:{}]: IDLE", (i >> 1), i&1);
}
else if (type == CODEWORD_TYPE_ADDRESS) {
// If a non-empty message is available, send it out and clear
flushMessage();
// Decode message type
msgType = (MessageType)((cw >> 11) & 0b11);
msgType = MESSAGE_TYPE_ALPHANUMERIC;
// msgType = (MessageType)((cw >> 11) & 0b11);
// Decode address and append lower 8 bits from position
addr = ((cw >> 13) & 0b111111111111111111) << 3;
@ -122,14 +157,38 @@ namespace pocsag {
// Decode data depending on message type
if (msgType == MESSAGE_TYPE_NUMERIC) {
// Numeric messages pack 5 characters per message codeword
msg += NUMERIC_CHARSET[(data >> 16) & 0b1111];
msg += NUMERIC_CHARSET[(data >> 12) & 0b1111];
msg += NUMERIC_CHARSET[(data >> 8) & 0b1111];
msg += NUMERIC_CHARSET[(data >> 4) & 0b1111];
msg += NUMERIC_CHARSET[data & 0b1111];
//msg += NUMERIC_CHARSET[(data >> 16) & 0b1111];
//msg += NUMERIC_CHARSET[(data >> 12) & 0b1111];
//msg += NUMERIC_CHARSET[(data >> 8) & 0b1111];
//msg += NUMERIC_CHARSET[(data >> 4) & 0b1111];
//msg += NUMERIC_CHARSET[data & 0b1111];
}
else if (msgType == MESSAGE_TYPE_ALPHANUMERIC) {
// Alpha messages pack 7bit characters in the entire codeword stream
// int lasti;
// for (int i = -leftInLast; i <= POCSAG_DATA_BITS_PER_CW-7; i += 7) {
// // Read 7 bits
// char c = 0;
// if (i < 0) {
// c = (lastMsgData & ((1 << (-i)) - 1)) << (7+i);
// }
// c |= (data >> (13 - i)) & 0b1111111;
// // Save character
// bitswapChar(c, c);
// msg += c;
// // Update last successful unpack
// lasti = i;
// }
// Pack the bits backwards
for (int i = 19; i >= 0; i--) {
msg += (char)((data >> i) & 1);
}
// Save how much is still left to read
//leftInLast = 20 - (lasti + 7);
}
// Save last data