From effeb8ed4a2a42a696d31c04e2c2c0e261e4d1f9 Mon Sep 17 00:00:00 2001
From: Chris Esposito <admin@espotek.com>
Date: Tue, 6 Nov 2018 10:46:47 +1100
Subject: [PATCH] Data decode _should_ work (untested)

---
 Desktop_Interface/i2cdecoder.cpp | 92 ++++++++++++++------------------
 Desktop_Interface/i2cdecoder.h   |  5 +-
 2 files changed, 42 insertions(+), 55 deletions(-)

diff --git a/Desktop_Interface/i2cdecoder.cpp b/Desktop_Interface/i2cdecoder.cpp
index 643e0c4a..39cfb0ff 100644
--- a/Desktop_Interface/i2cdecoder.cpp
+++ b/Desktop_Interface/i2cdecoder.cpp
@@ -140,92 +140,80 @@ void i2cDecoder::decodeAddress(edge sdaEdge, edge sclEdge)
 {
 	// Read in the next bit.
     if (sclEdge == edge::rising && sdaEdge == edge::held_high && currentBitIndex++ < addressBitStreamLength)
-    {
-        qDebug() << "1";
-        addressBitStream = (addressBitStream << 1) | 0x0001;
-        qDebug("%04x\n", addressBitStream);
-    }
+          currentBitStream = (currentBitStream << 1) | 0x0001;
     else if (sclEdge == edge::rising && sdaEdge == edge::held_low && currentBitIndex++ < addressBitStreamLength)
-    {
-        qDebug() << "0";
-        addressBitStream = (addressBitStream << 1) & 0xFFFE;
-        qDebug("%04x\n", addressBitStream);
-    }
+        currentBitStream = (currentBitStream << 1) & 0xFFFE;
     else
         return;
 
     if (currentBitIndex == addressBitStreamLength)
     {
         qDebug() << "Finished Address Decode";
-        if (addressBitStream & 0b0000000000000010)
-            serialBuffer->add("READ  ");
+        if (currentBitStream & 0b0000000000000010)
+            serialBuffer->add("READ:  ");
         else
-            serialBuffer->add("WRITE ");
+            serialBuffer->add("WRITE: ");
 
         char addressStr[8];
-        sprintf(addressStr, "0x%02x ", (addressBitStream & 0b0000000111111100) >> 2);
-
+        sprintf(addressStr, "0x%02x ", (currentBitStream & 0b0000000111111100) >> 2);
         serialBuffer->add(addressStr);
 
-        if (addressBitStream & 0b0000000000000001)
+        if (currentBitStream & 0b0000000000000001)
             serialBuffer->add("(NACK)");
 
         consoleStateInvalid = true;
+
+        // Prepare for next bit
+        currentBitIndex = 0;
+        currentBitStream = 0x0000;
+        state = transmissionState::data;
     }
 }
 
 void i2cDecoder::decodeData(edge sdaEdge, edge sclEdge)
 {
-	// Read in the next bit.
-	if(currentBitIndex < 8)
-	{	
-		if (sdaEdge == edge::rising && sclEdge == edge::held_high)
-			currentDataByte |= 0x01;
-		else if (sdaEdge == edge::rising && sclEdge == edge::held_low)
-			currentDataByte &= 0xFE;
-	
-		currentDataByte = currentDataByte << 1;
-		currentBitIndex++;
-	}
-	else // Full byte received, check for ACK.
-	{
-		dataByteCompleted(currentDataByte, sclEdge == edge::held_low);	
-		currentBitIndex = 0;
-	}
+    // Read in the next bit.
+    if (sclEdge == edge::rising && sdaEdge == edge::held_high && currentBitIndex++ < dataBitStreamLength)
+          currentBitStream = (currentBitStream << 1) | 0x0001;
+    else if (sclEdge == edge::rising && sdaEdge == edge::held_low && currentBitIndex++ < dataBitStreamLength)
+        currentBitStream = (currentBitStream << 1) & 0xFFFE;
+    else
+        return;
+
+    if (currentBitIndex == dataBitStreamLength)
+    {
+        qDebug() << "Finished Data byte Decode";
+
+        char dataStr[8];
+        sprintf(dataStr, "0x%02x ", (currentBitStream & 0b0000000111111110) >> 1);
+        serialBuffer->add(dataStr);
+
+        if (currentBitStream & 0b0000000000000001)
+            serialBuffer->add("(NACK)");
+
+        consoleStateInvalid = true;
+
+        // Prepare for next bit
+        currentBitIndex = 0;
+        currentBitStream = 0x0000;
+    }
 }
 
 void i2cDecoder::startCondition()
 {
 	currentBitIndex = 0;
-    addressBitStream = 0x0000;
+    currentBitStream = 0x0000;
 	state = transmissionState::address;	
     qDebug() << "I2C START";
 }
 
 void i2cDecoder::stopCondition()
 {
-	switch (state)
-	{
-		case transmissionState::address:		
-			currentBitIndex = 0;
-			state = transmissionState::data;
-            currentDataByte = 0;
-            serialBuffer->add('\n');
-			break;	
-		case transmissionState::data:		
-            state = transmissionState::idle;
-            qDebug() << "Data =" << currentDataByte;
-            serialBuffer->add('\n');
-			break;
-	}
+    state = transmissionState::idle;
+    serialBuffer->add('\n');
     qDebug() << "I2C STOP";
 }
 
-void i2cDecoder::dataByteCompleted(uint8_t byte, bool ACKed)
-{
-
-}
-
 void i2cDecoder::updateConsole(){
     std::lock_guard<std::mutex> lock(mutex);
     if (!consoleStateInvalid)
diff --git a/Desktop_Interface/i2cdecoder.h b/Desktop_Interface/i2cdecoder.h
index af51f026..253dc62e 100644
--- a/Desktop_Interface/i2cdecoder.h
+++ b/Desktop_Interface/i2cdecoder.h
@@ -28,6 +28,7 @@ enum class edge: uint8_t
 };
 
 constexpr uint8_t addressBitStreamLength = 9;
+constexpr uint8_t dataBitStreamLength = 9;
 constexpr uint32_t I2C_BUFFER_LENGTH = 8192;
 
 class i2cDecoder : public QObject
@@ -54,8 +55,7 @@ public:
 
 	// Data Transmission
 	uint8_t currentBitIndex = 0;
-    uint16_t addressBitStream;
-	uint8_t currentDataByte = 0;
+    uint16_t currentBitStream;
 
 	// Member functions
 	void updateBitValues();
@@ -67,7 +67,6 @@ public:
 	void decodeData(edge sdaEdge, edge sclEdge);
 	void startCondition();
 	void stopCondition();
-	void dataByteCompleted(uint8_t byte, bool ACKed);	
     void reset();
 signals:
 public slots: