- improved syncronization

- fixed inverted bit 

git-svn-id: http://moon:8086/svn/software/trunk/projects/GnuRadio@395 b431acfa-c32f-4a4a-93f1-934dc6c82436

gr-jay/lib/preamble_sync_impl.cc

@@ -35,16 +35,19 @@ preamble_sync::sptr preamble_sync::make()
 	return gnuradio::get_initial_sptr (new preamble_sync_impl());
 }
 
+const char* preamble_sync_impl::stateNames[NUM_STATES] = {"PreambleSlow", "SyncSlow", "DataSlow", "PreambleFast", "SyncFast", "DataFast"};
+
 /*
  * The private constructor
  */
 preamble_sync_impl::preamble_sync_impl()
 : gr::block("preamble_sync", gr::io_signature::make(1, 1, sizeof(uint8_t)), gr::io_signature::make(1, 1, sizeof(uint8_t)))
-, m_state(Init)
-, m_stateNext(Init)
+, m_state(PreambleSlow)
+, m_stateNext(PreambleSlow)
 , m_word(0)
 , m_wordCount(0)
-, m_preambleCount(0)
+, m_wordSize(1)
+, m_dataCount(0)
 {
 }
 
@@ -62,8 +65,8 @@ void preamble_sync_impl::forecast (int noutput_items, gr_vector_int &ninput_item
 
 int preamble_sync_impl::general_work (int noutput_items, gr_vector_int &ninput_items, gr_vector_const_void_star &input_items, gr_vector_void_star &output_items)
 {
-	size_t const word_size = 8;
-	
+	uint8_t zero = 0x01;
+	const uint8_t fastSyncWord[4] = {0x7C, 0xD2, 0x15, 0xD8};
 	const uint8_t *in = (const uint8_t *) input_items[0];
 	uint8_t *out = (uint8_t *) output_items[0];
 
@@ -74,14 +77,23 @@ int preamble_sync_impl::general_work (int noutput_items, gr_vector_int &ninput_i
 	{
 		if (in[i] == 0xFF)
 		{
-			if (m_state != Init)
+			if (m_state != PreambleSlow)
 			{
-				m_state = Init;
-				fprintf(stderr, "Init\n");
+				m_state = PreambleSlow;
+				m_wordCount = 0;
+				fprintf(stderr, "Reset\n");
 			}
 			continue;
 		}
-		m_word = (m_word << 1) | in[i];
+		
+		if (in[i] == zero)
+		{
+			m_word = (m_word << 1) | 0;
+		}
+		else
+		{
+			m_word = (m_word << 1) | 1;
+		}
 		
 		if (m_wordCount != 0)
 		{
@@ -89,63 +101,64 @@ int preamble_sync_impl::general_work (int noutput_items, gr_vector_int &ninput_i
 			continue;
 		}
 		
-		m_word &= (typeof(m_word))(1 << word_size)-1;
 		m_stateNext = m_state;
 		switch (m_state)
 		{
-			case Init:
-				if (m_word != 0xCC)
+			case PreambleSlow:
+				if ((m_word & 0xFF) == 0xCC)
 				{
-					m_wordCount = 0;
-					m_preambleCount = 8;
+					m_wordSize = 1;
+					m_stateNext = SyncSlow;
 				}
-				else
+				break;
+			case SyncSlow:
+				if ((m_word & 0xFF) == 0x3F)
 				{
-					m_wordCount = word_size-1;
-					if (m_preambleCount)
+					m_wordSize = 8;
+					m_dataCount = 1;
+					out[j++] = m_word;
+					m_stateNext = DataSlow;
+				}
+				break;
+			case DataSlow:
+				m_dataCount++;
+				out[j++] = m_word;
+				if (m_dataCount == 0xA0)
+				{
+					m_wordSize = 1;
+					m_stateNext = PreambleFast;
+				}
+				break;
+			case PreambleFast:
+				if ((m_word & 0xFF) == 0xAA)
+				{
+					m_wordSize = 8;
+					m_dataCount = 0;
+					m_stateNext = SyncFast;
+				}
+				break;
+			case SyncFast:
+				if ((m_word & 0xFF) == fastSyncWord[m_dataCount])
+				{
+					out[j++] = m_word;
+					m_dataCount++;
+					if (m_dataCount == 4)
 					{
-						m_preambleCount--;
-					}
-					else
-					{
-						m_stateNext = Preamble;
-						fprintf(stderr, "Preamble\n");
+						m_stateNext = DataFast;
 					}
 				}
 				break;
-			case Preamble:
-				m_wordCount = word_size-1;
-				if (m_word == 0xC0)
-				{
-					m_stateNext = Sync;
-					fprintf(stderr, "Sync 1\n");
-				}
-				else if (m_word == 0xCF)
-				{
-					m_stateNext = Sync;
-					fprintf(stderr, "Sync 2\n");
-				}
-				else if (m_word == 0xF0)
-				{
-					m_wordCount = word_size/2-1;
-					m_stateNext = Sync;
-					fprintf(stderr, "Sync 3\n");
-				}
-				else if (m_word != 0xCC)
-				{
-					m_wordCount = 0;
-					m_stateNext = Init;
-				}
-				break;
-			case Sync:
-				m_wordCount = word_size-1;
+			case DataFast:
+				m_wordSize = 8;
 				out[j++] = m_word;
 				break;
+				
 		}
 		if (m_state != m_stateNext)
 		{
-			fprintf(stderr, "State changed\n");
+			fprintf(stderr, "State changed: %s => %s\n", stateNames[m_state], stateNames[m_stateNext]);
 		}
+		m_wordCount = m_wordSize - 1;
 		m_state = m_stateNext;
 	}
 
@@ -155,6 +168,7 @@ int preamble_sync_impl::general_work (int noutput_items, gr_vector_int &ninput_i
 
 	// Tell runtime system how many output items we produced.
 	return j;
+
 }
 
 } /* namespace jay */

gr-jay/lib/preamble_sync_impl.h

@@ -33,16 +33,25 @@ class preamble_sync_impl : public preamble_sync
     private:
 	enum State
 	{
-		Init,
-		Preamble,
-		Sync
+		PreambleSlow = 0,
+		SyncSlow,
+		DataSlow,
+		PreambleFast,
+		SyncFast,
+		DataFast,
+		NUM_STATES
+		
 	};
 		
+	static const char *stateNames[NUM_STATES];
+	
 	State m_state;
 	State m_stateNext;
 	uint32_t m_word;
 	size_t m_wordCount;
-	size_t m_preambleCount;
+	size_t m_wordSize;
+	size_t m_dataCount;
+
 	public:
 	preamble_sync_impl();
     ~preamble_sync_impl();