From f2d2033733bc911aaa2d93f2eb8ab5a3b93803e4 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Wed, 14 Oct 2020 13:29:23 +0100
Subject: [PATCH] Add the sync and RRC 0.5 data and code.

---
 IO.cpp       |  6 +++---
 M17Defines.h | 14 +++++++-------
 M17RX.cpp    |  2 +-
 M17RX.h      |  2 +-
 M17TX.cpp    |  6 +++---
 5 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/IO.cpp b/IO.cpp
index 4e2e86a..f98e991 100644
--- a/IO.cpp
+++ b/IO.cpp
@@ -33,9 +33,9 @@ static q15_t RRC_0_2_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 147
 const uint16_t RRC_0_2_FILTER_LEN = 42U;
 
 // Generated using rcosdesign(0.5, 8, 5, 'sqrt') in MATLAB
-static q15_t RRC_0_5_FILTER[] = {401, 104, -340, -731, -847, -553, 112, 909, 1472, 1450, 683, -675, -2144, -3040, -2706, -770, 2667, 6995,
-                                 11237, 14331, 15464, 14331, 11237, 6995, 2667, -770, -2706, -3040, -2144, -675, 683, 1450, 1472, 909, 112,
-                                 -553, -847, -731, -340, 104, 401, 0};
+static q15_t RRC_0_5_FILTER[] = {-147, -88, 72, 220, 223, 46, -197, -285, -79, 334, 623, 390, -498, -1691, -2363, -1556, 1284, 5872, 11033,
+				  15109, 16656, 15109, 11033, 5872, 1284, -1556, -2363, -1691, -498, 390, 623, 334, -79, -285, -197, 46, 223,
+				  220, 72, -88, -147, 0};
 const uint16_t RRC_0_5_FILTER_LEN = 42U;
 
 // Generated using rcosdesign(0.2, 8, 10, 'sqrt') in MATLAB
diff --git a/M17Defines.h b/M17Defines.h
index 47b02c1..4947341 100644
--- a/M17Defines.h
+++ b/M17Defines.h
@@ -30,18 +30,18 @@ const unsigned int M17_SYNC_LENGTH_BITS    = 16U;
 const unsigned int M17_SYNC_LENGTH_SYMBOLS = M17_SYNC_LENGTH_BITS / 2U;
 const unsigned int M17_SYNC_LENGTH_SAMPLES = M17_SYNC_LENGTH_SYMBOLS * M17_RADIO_SYMBOL_LENGTH;
 
-const uint8_t M17_SYNC_BYTES[]      = {0xCDU, 0xF5U};	// XXX
+const uint8_t M17_SYNC_BYTES[]      = {0x32U, 0x43U};
 const uint8_t M17_SYNC_BYTES_LENGTH = 2U;
 
-const uint16_t M17_SYNC_BITS      = 0xCDF5U;			// XXX
+const uint16_t M17_SYNC_BITS      = 0x3243U;
 
-// C     D      F      5					// XXX
-// 11 00 11 01  11 11  01 01					// XXX
-// -3 +1 -3 +3  -3 -3  +3 +3					// XXX
+// 3     2      4      3
+// 00 11 00 10  01 00  00 11
+// +1 -3 +1 -1  +3 +1  +1 -3
 
-const int8_t M17_SYNC_SYMBOLS_VALUES[] = {-3, +1, -3, +3, -3, -3, +3, +3};	// XXX
+const int8_t M17_SYNC_SYMBOLS_VALUES[] = {+1, -3, +1, -1, +3, +1, +1, -3};
 
-const uint16_t M17_SYNC_SYMBOLS = 0x014DU;			// XXX
+const uint8_t M17_SYNC_SYMBOLS = 0xAEU;
 
 #endif
 
diff --git a/M17RX.cpp b/M17RX.cpp
index 06e9240..3633fbe 100644
--- a/M17RX.cpp
+++ b/M17RX.cpp
@@ -204,7 +204,7 @@ void CM17RX::processData(q15_t sample)
 
 bool CM17RX::correlateSync()
 {
-  if (countBits16(m_bitBuffer[m_bitPtr] ^ M17_SYNC_SYMBOLS) <= MAX_SYNC_SYMBOLS_ERRS) {
+  if (countBits8(m_bitBuffer[m_bitPtr] ^ M17_SYNC_SYMBOLS) <= MAX_SYNC_SYMBOLS_ERRS) {
     uint16_t ptr = m_dataPtr + M17_FRAME_LENGTH_SAMPLES - M17_SYNC_LENGTH_SAMPLES + M17_RADIO_SYMBOL_LENGTH;
     if (ptr >= M17_FRAME_LENGTH_SAMPLES)
       ptr -= M17_FRAME_LENGTH_SAMPLES;
diff --git a/M17RX.h b/M17RX.h
index 7d6dc6f..6826fee 100644
--- a/M17RX.h
+++ b/M17RX.h
@@ -37,7 +37,7 @@ public:
 
 private:
   M17RX_STATE m_state;
-  uint16_t    m_bitBuffer[M17_RADIO_SYMBOL_LENGTH];
+  uint8_t     m_bitBuffer[M17_RADIO_SYMBOL_LENGTH];
   q15_t       m_buffer[M17_FRAME_LENGTH_SAMPLES];
   uint16_t    m_bitPtr;
   uint16_t    m_dataPtr;
diff --git a/M17TX.cpp b/M17TX.cpp
index 41d8d2b..3aa2ba1 100644
--- a/M17TX.cpp
+++ b/M17TX.cpp
@@ -24,9 +24,9 @@
 #include "M17Defines.h"
 
 // Generated using rcosdesign(0.5, 8, 5, 'sqrt') in MATLAB
-static q15_t RRC_0_5_FILTER[] = {0, 0, 0, 0, 850, 219, -720, -1548, -1795, -1172, 237, 1927, 3120, 3073, 1447, -1431, -4544, -6442,
-                                 -5735, -1633, 5651, 14822, 23810, 30367, 32767, 30367, 23810, 14822, 5651, -1633, -5735, -6442,
-                                 -4544, -1431, 1447, 3073, 3120, 1927, 237, -1172, -1795, -1548, -720, 219, 850}; // numTaps = 45, L = 5
+static q15_t RRC_0_5_FILTER[] = {0, 0, 0, 0, -147, -88, 72, 220, 223, 46, -197, -285, -79, 334, 623, 390, -498, -1691, -2363, -1556,
+				  1284, 5872, 11033, 15109, 16656, 15109, 11033, 5872, 1284, -1556, -2363, -1691, -498, 390, 623, 334,
+				  -79, -285, -197, 46, 223, 220, 72, -88, -147}; // numTaps = 45, L = 5
 const uint16_t RRC_0_5_FILTER_PHASE_LEN = 9U; // phaseLength = numTaps/L
 
 const q15_t M17_LEVELA =  1683;