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POCSAG TX (with fixed message for testing)

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This commit is contained in:
furrtek 2017-02-07 17:48:17 +00:00
parent b430b1e427
commit dc7fcbc6c3
22 changed files with 562 additions and 91 deletions
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81
firmware/common/pocsag.cpp
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@ -94,19 +94,20 @@ void pocsag_encode(
}
// Address
codeword = (address & 0x1FFFF8U) << 13;
codeword = (address & 0x1FFFF8U) << 10;
address_slot = (address & 7) * 2;
// Function
codeword = 3 << 11;
codeword |= (3 << 11);
insert_BCH(BCH_code, &codeword);
// Address batch
codewords.push_back(POCSAG_SYNCWORD);
for (c = 0; c < 16; c++) {
if (c == address_slot)
if (c == address_slot) {
codewords.push_back(codeword);
else
break;
} else
codewords.push_back(POCSAG_IDLEWORD);
}
@ -115,44 +116,52 @@ void pocsag_encode(
// Messages batch(es)
do {
codewords.push_back(POCSAG_SYNCWORD);
if (c == 0) codewords.push_back(POCSAG_SYNCWORD);
for (c = 0; c < 16; c++) {
// Fill up 20 bits
do {
bit_idx -= 7;
if (char_idx < text_size)
ascii_char = text[char_idx] & 0x7F;
else
ascii_char = 0; // Padding
// Bottom's up
ascii_char = (ascii_char & 0xF0) >> 4 | (ascii_char & 0x0F) << 4; // *6543210 -> 3210*654
ascii_char = (ascii_char & 0xCC) >> 2 | (ascii_char & 0x33) << 2; // 3210*654 -> 103254*6
ascii_char = (ascii_char & 0xAA) >> 2 | (ascii_char & 0x55); // 103254*6 -> *0123456
codeword |= (ascii_char << bit_idx);
char_idx++;
} while (bit_idx > 11);
for ( ; c < 16; c++) {
codeword &= 0x7FFFF800; // Trim data
codeword |= 0x80000000; // Message type
insert_BCH(BCH_code, &codeword);
codewords.push_back(codeword);
if (bit_idx != 11) {
bit_idx = 20 + bit_idx;
codeword = ascii_char << bit_idx;
if (char_idx < text_size) {
// Fill up 20 bits
do {
bit_idx -= 7;
if (char_idx < text_size)
ascii_char = text[char_idx] & 0x7F;
else
ascii_char = 0; // Codeword padding
// Bottom's up
ascii_char = (ascii_char & 0xF0) >> 4 | (ascii_char & 0x0F) << 4; // *6543210 -> 3210*654
ascii_char = (ascii_char & 0xCC) >> 2 | (ascii_char & 0x33) << 2; // 3210*654 -> 103254*6
ascii_char = (ascii_char & 0xAA) >> 2 | (ascii_char & 0x55); // 103254*6 -> *0123456
codeword |= (ascii_char << bit_idx);
char_idx++;
} while (bit_idx > 11);
codeword &= 0x7FFFF800; // Trim data
codeword |= 0x80000000; // Message type
insert_BCH(BCH_code, &codeword);
codewords.push_back(codeword);
if (bit_idx != 11) {
bit_idx = 20 + bit_idx;
codeword = ascii_char << bit_idx;
} else {
bit_idx = 20 + 11;
codeword = 0;
}
} else {
bit_idx = 20 + 11;
codeword = 0;
codewords.push_back(POCSAG_IDLEWORD); // Batch padding
}
}
c = 0;
} while (char_idx < text_size);
}