From 300a6be90f0428911c3376d6e655a4bd0333b4f8 Mon Sep 17 00:00:00 2001
From: Youen Toupin <youen.toupin@gmail.com>
Date: Sun, 26 Apr 2015 21:09:30 +0200
Subject: [PATCH] added background reset check (in case the master sends a
 reset while another operation had started)

---
 OneWireSlave.cpp | 174 +++++++++++++++++++++++++++--------------------
 OneWireSlave.h   |   4 ++
 2 files changed, 106 insertions(+), 72 deletions(-)

diff --git a/OneWireSlave.cpp b/OneWireSlave.cpp
index ca8deba..0ae7cdb 100644
--- a/OneWireSlave.cpp
+++ b/OneWireSlave.cpp
@@ -179,84 +179,31 @@ void OneWireSlave::releaseBus_()
 #endif
 }
 
-void OneWireSlave::beginWaitReset_()
+void OneWireSlave::beginResetDetection_()
+{
+	setTimerEvent_(ResetMinDuration - 50, &OneWireSlave::resetCheck_);
+	resetStart_ = micros() - 50;
+}
+
+void OneWireSlave::cancelResetDetection_()
 {
 	disableTimer_();
-	pin_.attachInterrupt(&OneWireSlave::waitReset_, CHANGE);
-	resetStart_ = (unsigned int)-1;
+	resetStart_ = (unsigned long)-1;
 }
 
-void OneWireSlave::waitReset_()
+void OneWireSlave::resetCheck_()
 {
 	onEnterInterrupt_();
-	bool state = pin_.read();
-	unsigned long now = micros();
-	if (state)
+	if (!pin_.read())
 	{
-		if (resetStart_ == (unsigned int)-1)
-		{
-			onLeaveInterrupt_();
-			return;
-		}
-
-		unsigned long resetDuration = now - resetStart_;
-		resetStart_ = (unsigned int)-1;
-		if (resetDuration >= ResetMinDuration)
-		{
-			if (resetDuration > ResetMaxDuration)
-			{
-				error_("Reset too long");
-				onLeaveInterrupt_();
-				return;
-			}
-
-			lastReset_ = now;
-			pin_.detachInterrupt();
-			setTimerEvent_(PresenceWaitDuration - (micros() - now), &OneWireSlave::beginPresence_);
-		}
-	}
-	else
-	{
-		resetStart_ = now;
+		pin_.attachInterrupt(&OneWireSlave::waitReset_, CHANGE);
+		#ifdef DEBUG_LOG
+		debug.SC_APPEND_STR("Reset detected during another operation");
+		#endif
 	}
 	onLeaveInterrupt_();
 }
 
-void OneWireSlave::beginPresence_()
-{
-	unsigned long now = micros();
-	pullLow_();
-	setTimerEvent_(PresenceDuration, &OneWireSlave::endPresence_);
-	#ifdef DEBUG_LOG
-	debug.SC_APPEND_STR_TIME("reset", lastReset_);
-	debug.SC_APPEND_STR_TIME("beginPresence", now);
-	#endif
-}
-
-void OneWireSlave::endPresence_()
-{
-	unsigned long now = micros();
-	releaseBus_();
-	#ifdef DEBUG_LOG
-	debug.SC_APPEND_STR_TIME("endPresence", now);
-	#endif
-
-	beginWaitCommand_();
-}
-
-void OneWireSlave::beginWaitCommand_()
-{
-	receiveTarget_ = ReceiveCommand;
-	beginReceive_();
-}
-
-void OneWireSlave::beginReceive_()
-{
-	receivingByte_ = 0;
-	receivingBitPos_ = 0;
-	beginReceiveBit_(&OneWireSlave::onBitReceived_);
-}
-
 void OneWireSlave::beginReceiveBit_(void(*completeCallback)(bool bit, bool error))
 {
 	receiveBitCallback_ = completeCallback;
@@ -273,6 +220,22 @@ void OneWireSlave::receive_()
 	onLeaveInterrupt_();
 }
 
+void OneWireSlave::readBit_()
+{
+	onEnterInterrupt_();
+
+	bool bit = pin_.read();
+	if (bit)
+		cancelResetDetection_();
+	else
+		beginResetDetection_();
+	receiveBitCallback_(bit, false);
+	//dbgOutput.writeLow();
+	//dbgOutput.writeHigh();
+
+	onLeaveInterrupt_();
+}
+
 void OneWireSlave::beginSendBit_(bool bit, void(*completeCallback)(bool error))
 {
 	bitSentCallback_ = completeCallback;
@@ -290,6 +253,7 @@ void OneWireSlave::sendBitOne_()
 {
 	onEnterInterrupt_();
 
+	beginResetDetection_();
 	bitSentCallback_(false);
 
 	onLeaveInterrupt_();
@@ -317,18 +281,84 @@ void OneWireSlave::endSendBitZero_()
 	onLeaveInterrupt_();
 }
 
-void OneWireSlave::readBit_()
+void OneWireSlave::beginWaitReset_()
+{
+	disableTimer_();
+	pin_.attachInterrupt(&OneWireSlave::waitReset_, CHANGE);
+	resetStart_ = (unsigned int)-1;
+}
+
+void OneWireSlave::waitReset_()
 {
 	onEnterInterrupt_();
+	bool state = pin_.read();
+	unsigned long now = micros();
+	if (state)
+	{
+		if (resetStart_ == (unsigned int)-1)
+		{
+			onLeaveInterrupt_();
+			return;
+		}
 
-	bool bit = pin_.read();
-	receiveBitCallback_(bit, false);
-	//dbgOutput.writeLow();
-	//dbgOutput.writeHigh();
+		unsigned long resetDuration = now - resetStart_;
+		resetStart_ = (unsigned int)-1;
+		if (resetDuration >= ResetMinDuration)
+		{
+			if (resetDuration > ResetMaxDuration)
+			{
+				error_("Reset too long");
+				onLeaveInterrupt_();
+				return;
+			}
 
+			lastReset_ = now;
+			pin_.detachInterrupt();
+			setTimerEvent_(PresenceWaitDuration - (micros() - now), &OneWireSlave::beginPresence_);
+		}
+	}
+	else
+	{
+		resetStart_ = now;
+	}
 	onLeaveInterrupt_();
 }
 
+void OneWireSlave::beginPresence_()
+{
+	unsigned long now = micros();
+	pullLow_();
+	setTimerEvent_(PresenceDuration, &OneWireSlave::endPresence_);
+	#ifdef DEBUG_LOG
+	debug.SC_APPEND_STR_TIME("reset", lastReset_);
+	debug.SC_APPEND_STR_TIME("beginPresence", now);
+	#endif
+}
+
+void OneWireSlave::endPresence_()
+{
+	unsigned long now = micros();
+	releaseBus_();
+	#ifdef DEBUG_LOG
+	debug.SC_APPEND_STR_TIME("endPresence", now);
+	#endif
+
+	beginWaitCommand_();
+}
+
+void OneWireSlave::beginWaitCommand_()
+{
+	receiveTarget_ = ReceiveCommand;
+	beginReceive_();
+}
+
+void OneWireSlave::beginReceive_()
+{
+	receivingByte_ = 0;
+	receivingBitPos_ = 0;
+	beginReceiveBit_(&OneWireSlave::onBitReceived_);
+}
+
 void OneWireSlave::onBitReceived_(bool bit, bool error)
 {
 	if (error)
diff --git a/OneWireSlave.h b/OneWireSlave.h
index 0275698..73ecee7 100644
--- a/OneWireSlave.h
+++ b/OneWireSlave.h
@@ -39,6 +39,9 @@ private:
 	static void beginReceiveBit_(void(*completeCallback)(bool bit, bool error));
 	static void beginSendBit_(bool bit, void(*completeCallback)(bool error));
 
+	static void beginResetDetection_();
+	static void cancelResetDetection_();
+
 	static void beginWaitReset_();
 	static void beginWaitCommand_();
 	static void beginReceive_();
@@ -58,6 +61,7 @@ private:
 	static void sendBitOne_();
 	static void sendBitZero_();
 	static void endSendBitZero_();
+	static void resetCheck_();
 
 private:
 	static byte rom_[8];