From c09d8c78ee1ce9f17d8a50592b31cbbad995a15e Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <naylorjs@yahoo.com>
Date: Tue, 23 Feb 2016 20:51:57 +0000
Subject: [PATCH] Allow for sync-less data frames.

---
 DMRSlotRX.cpp | 41 ++++++++++++++++++++++++++++++++++-------
 DMRSlotRX.h   |  7 +++++++
 2 files changed, 41 insertions(+), 7 deletions(-)

diff --git a/DMRSlotRX.cpp b/DMRSlotRX.cpp
index a076f61..15c843f 100644
--- a/DMRSlotRX.cpp
+++ b/DMRSlotRX.cpp
@@ -49,7 +49,8 @@ m_threshold(0),
 m_control(0x00U),
 m_syncCount(0U),
 m_colorCode(0U),
-m_n(0U)
+m_n(0U),
+m_state(DMRSRXS_NONE)
 {
 }
 
@@ -72,13 +73,14 @@ void CDMRSlotRX::reset()
   m_threshold = 0;
   m_centre    = 0;
   m_endPtr    = NOENDPTR;
+  m_state     = DMRSRXS_NONE;
 }
 
 bool CDMRSlotRX::processSample(q15_t sample)
 {
   // Ensure that the buffer doesn't overflow
   if (m_dataPtr > m_endPtr || m_dataPtr >= 900U)
-    return m_endPtr != NOENDPTR;
+    return m_state != DMRSRXS_NONE;
 
   m_buffer[m_dataPtr] = sample;
 
@@ -119,14 +121,24 @@ bool CDMRSlotRX::processSample(q15_t sample)
 
         switch (dataType) {
           case DT_DATA_HEADER:
+            m_state = DMRSRXS_DATA;
+            DEBUG3("DMRSlotRX: data header for slot/data type", m_slot ? 2U : 1U, dataType);
+            serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
+            break;
           case DT_VOICE_LC_HEADER:
+            m_state = DMRSRXS_VOICE;
+            DEBUG3("DMRSlotRX: voice header for slot/data type", m_slot ? 2U : 1U, dataType);
+            serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
+            break;
           case DT_VOICE_PI_HEADER:
-            DEBUG3("DMRSlotRX: header for slot/data type", m_slot ? 2U : 1U, dataType);
+            m_state = DMRSRXS_VOICE;
+            DEBUG3("DMRSlotRX: pi header for slot/data type", m_slot ? 2U : 1U, dataType);
             serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
             break;
           case DT_TERMINATOR_WITH_LC:
             DEBUG2("DMRSlotRX: terminator for slot", m_slot ? 2U : 1U);
             m_endPtr = NOENDPTR;
+            m_state  = DMRSRXS_NONE;
             serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
             break;
           default:
@@ -139,6 +151,7 @@ bool CDMRSlotRX::processSample(q15_t sample)
       // Voice sync
       DEBUG2("DMRSlotRX: voice sync for slot", m_slot ? 2U : 1U);
       serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
+      m_state     = DMRSRXS_VOICE;
       m_syncCount = 0U;
       m_n         = 0U;
     } else {
@@ -150,12 +163,26 @@ bool CDMRSlotRX::processSample(q15_t sample)
         m_threshold = 0;
         m_centre    = 0;
         m_endPtr    = NOENDPTR;
+        m_state     = DMRSRXS_NONE;
         return false;
       }
 
-      // Voice data
-      frame[0U] |= ++m_n;
-      serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
+      if (m_state == DMRSRXS_VOICE) {
+        // Voice data
+        frame[0U] |= ++m_n;
+        serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
+      } else if (m_state == DMRSRXS_DATA) {
+        // Data data
+        uint8_t colorCode;
+        uint8_t dataType;
+        CDMRSlotType slotType;
+        slotType.decode(frame + 1U, colorCode, dataType);
+
+        if (colorCode == m_colorCode) {
+          frame[0U] |= dataType;
+          serial.writeDMRData(m_slot, frame, DMR_FRAME_LENGTH_BYTES + 1U);
+        }
+      }
     }
   }
 
@@ -165,7 +192,7 @@ bool CDMRSlotRX::processSample(q15_t sample)
   if (m_bitPtr >= DMR_RADIO_SYMBOL_LENGTH)
     m_bitPtr = 0U;
 
-  return m_endPtr != NOENDPTR;
+  return m_state != DMRSRXS_NONE;
 }
 
 void CDMRSlotRX::correlateSync(q15_t sample)
diff --git a/DMRSlotRX.h b/DMRSlotRX.h
index 0ac8d92..99aef33 100644
--- a/DMRSlotRX.h
+++ b/DMRSlotRX.h
@@ -22,6 +22,12 @@
 #include "Config.h"
 #include "DMRDefines.h"
 
+enum DMRSRXS {
+  DMRSRXS_NONE,
+  DMRSRXS_VOICE,
+  DMRSRXS_DATA
+};
+
 class CDMRSlotRX {
 public:
   CDMRSlotRX(bool slot);
@@ -49,6 +55,7 @@ private:
   uint8_t  m_syncCount;
   uint8_t  m_colorCode;
   uint8_t  m_n;
+  DMRSRXS  m_state;
 
   void    correlateSync(q15_t sample);
   void    samplesToBits(uint16_t start, uint8_t count, uint8_t* buffer, uint16_t offset, q15_t centre, q15_t threshold);