improved debugging messages on serial port (approximate measured time to append a message : 10µs ; messages are actually sent later, from the main loop)

OneWireIO.ino

@@ -6,9 +6,12 @@
 #define OWPin 2
 #define InterruptNumber 0 // Must correspond to the OWPin to correctly detect state changes. On Arduino Uno, interrupt 0 is for digital pin 2
 
-#define ResetMinDuration 360
+#define ResetMinDuration 480
 #define ResetMaxDuration 900
 
+#define PresenceWaitDuration 30
+#define PresenceDuration 150
+
 SerialChannel debug("debug");
 
 Pin owPin(OWPin);
@@ -16,6 +19,16 @@ Pin ledPin(LEDPin);
 
 unsigned long resetStart = (unsigned long)-1;
 
+enum Status
+{
+	S_WaitReset,
+	S_WaitPresence,
+	S_Presence,
+};
+
+Status status = S_WaitReset;
+unsigned long statusChangeTime = (unsigned long)-1;
+
 void setup()
 {
 	ledPin.outputMode();
@@ -31,9 +44,10 @@ void setup()
 void loop()
 {
     cli();//disable interrupts
-    
+	SerialChannel::swap();
     sei();//enable interrupts
     
+	SerialChannel::flush();
 }
 
 void onewireInterrupt(void)
@@ -48,12 +62,15 @@ void onewireInterrupt(void)
 
 	if (state)
 	{
-		unsigned long resetDuration = now - resetStart;
-		if (resetStart != (unsigned long)-1 && resetDuration >= ResetMinDuration && resetDuration <= ResetMaxDuration)
+		unsigned long resetDuration = resetStart == (unsigned long)-1 ? (unsigned long)-1 : now - resetStart;
+		resetStart = (unsigned long)-1;
+
+		if (resetDuration >= ResetMinDuration && resetDuration <= ResetMaxDuration)
 		{
-			debug.write("reset");
-			ledPin.writeHigh();
+			debug.SC_APPEND_STR_TIME("reset", now);
+			status = S_WaitPresence;
+			statusChangeTime = now;
+			return;
 		}
-		resetStart = (unsigned long)-1;
 	}
 }

SerialChannel.cpp

@@ -4,6 +4,12 @@
 byte SerialChannel::nextId = 1;
 SerialChannel* SerialChannel::first = 0;
 
+SerialChannel::Message SerialChannel::buffer1[SerialChannel::MaxPendingMessages];
+SerialChannel::Message SerialChannel::buffer2[SerialChannel::MaxPendingMessages];
+SerialChannel::Message* SerialChannel::backBuffer;
+byte SerialChannel::backBufferPos;
+byte SerialChannel::frontBufferSize;
+
 SerialChannel::SerialChannel(const char* name_)
     : next(0)
     , id((byte)-1)
@@ -21,6 +27,14 @@ SerialChannel::SerialChannel(const char* name_)
     id = nextId++;
 }
 
+void SerialChannel::beginWriteInChannel(byte id, short byteCount, unsigned long time)
+{
+	Serial.write("START");
+	Serial.write(id);
+	writeULong(time);
+	writeShort(byteCount);
+}
+
 void SerialChannel::write(byte* data, short byteCount, unsigned long time)
 {
 	beginWrite(byteCount, time);
@@ -34,10 +48,7 @@ void SerialChannel::beginWrite(short byteCount, unsigned long time)
 
 	handleConnection();
 
-	Serial.write("START");
-	Serial.write(id);
-	writeULong(time);
-	writeShort(byteCount);
+	beginWriteInChannel(id, byteCount, time);
 }
 
 void SerialChannel::continueWrite(byte* data, short byteCount)
@@ -50,6 +61,44 @@ void SerialChannel::write(const char* text, unsigned long time)
     write((byte*)text, strlen(text), time);
 }
 
+void SerialChannel::append(byte* data, short byteCount, unsigned long time)
+{
+	if (time == (unsigned long)-1)
+		time = micros();
+
+	Message& msg = backBuffer[backBufferPos++];
+	if (backBufferPos >= MaxPendingMessages)
+		backBufferPos = MaxPendingMessages - 1;
+	msg.id = id;
+	msg.data = data;
+	msg.byteCount = byteCount;
+	msg.time = time;
+}
+
+void SerialChannel::append(const char* text, unsigned long time)
+{
+	append((byte*)text, strlen(text), time);
+}
+
+void SerialChannel::swap()
+{
+	backBuffer = backBuffer == buffer1 ? buffer2 : buffer1;
+	frontBufferSize = backBufferPos;
+	backBufferPos = 0;
+}
+
+void SerialChannel::flush()
+{
+	handleConnection();
+
+	Message* frontBuffer = backBuffer == buffer1 ? buffer2 : buffer1;
+	for (Message* msg = frontBuffer; msg < frontBuffer + frontBufferSize; ++msg)
+	{
+		beginWriteInChannel(msg->id, msg->byteCount, msg->time);
+		Serial.write(msg->data, msg->byteCount);
+	}
+}
+
 void SerialChannel::writeShort(short num)
 {
     Serial.write((byte*)&num, 2);
@@ -77,6 +126,7 @@ void SerialChannel::handleConnection()
             Serial.write(c->name);
             c = c->next;
         }
+		Serial.flush();
     }
 }
 

SerialChannel.h

@@ -1,9 +1,22 @@
 #ifndef _SerialChannel_h_
 #define _SerialChannel_h_
 
+#define SC_APPEND_STR(str) append((byte*)str, sizeof(str)-1)
+#define SC_APPEND_STR_TIME(str, time) append((byte*)str, sizeof(str)-1, time)
+
 class SerialChannel
 {
 private:
+	static const byte MaxPendingMessages = 16;
+
+	struct Message
+	{
+		byte* data;
+		unsigned long time;
+		short byteCount;
+		byte id;
+	};
+
     static SerialChannel* first;
     SerialChannel* next;
     
@@ -11,20 +24,31 @@ private:
     byte id;
     const char* name;
 
+	static Message buffer1[MaxPendingMessages];
+	static Message buffer2[MaxPendingMessages];
+	static Message* backBuffer;
+	static byte backBufferPos;
+	static byte frontBufferSize;
+
 public:
     SerialChannel(const char* name_);
     
+	static void beginWriteInChannel(byte id, short byteCount, unsigned long time);
     void write(byte* data, short byteCount, unsigned long time = (unsigned long)-1);
-    
     void write(const char* text, unsigned long time = (unsigned long)-1);
 
 	void beginWrite(short byteCount, unsigned long time = (unsigned long)-1);
 	void continueWrite(byte* data, short byteCount);
 
+	void append(byte* data, short byteCount, unsigned long time = (unsigned long)-1);
+	void append(const char* text, unsigned long time = (unsigned long)-1);
+	static void swap();
+	static void flush();
+    
 private:
-    void handleConnection();
-    void writeShort(short num);
-    void writeULong(unsigned long num);
+    static void handleConnection();
+    static void writeShort(short num);
+    static void writeULong(unsigned long num);
 };
 
 #endif

SerialMonitor/SerialMonitor/App.xaml.cs

@@ -80,7 +80,7 @@ namespace SerialMonitor
             switch (message.ChannelName)
             {
                 case "debug":
-                    string text = ((float)message.SendTime / 1000000).ToString("0.000") + "s " + message.StringData;
+                    string text = ((float)message.SendTime / 1000000).ToString("0.000000") + "s " + message.StringData;
                     //Debug.WriteLine(text);
                     MainWindowContext.Get.WriteLine(text);
                     break;