Various

Support layer counting in GCode files generated by SuperSlicer
When reporting a bad command, display any non-printing characters in hex
Support measuring fan RPMs down to 160 instead of down to 320
After turning a remote heater on, if it was previously off then set its
status to 'heating' pending receiving updated status for it, to make
sure that M116 waits for it

15 files changed, 105 insertions, 39 deletions

diff --git a/src/CAN/CanInterface.cpp b/src/CAN/CanInterface.cpp
index 764a73c2..710f14e9 100644
--- a/src/CAN/CanInterface.cpp
+++ b/src/CAN/CanInterface.cpp
@@ -179,8 +179,12 @@ static Task<CanReceiverTaskStackWords> canReceiverTask;
 constexpr size_t CanClockTaskStackWords = 400;			// used to be 300 but RD had a stack overflow
 static Task<CanSenderTaskStackWords> canClockTask;
 
-static CanMessageBuffer * volatile pendingBuffers;
-static CanMessageBuffer * volatile lastBuffer;			// only valid when pendingBuffers != nullptr
+static CanMessageBuffer * volatile pendingMotionBuffers = nullptr;
+static CanMessageBuffer * volatile lastMotionBuffer;			// only valid when pendingBuffers != nullptr
+
+#if 0	//unused
+static unsigned int numPendingMotionBuffers = 0;
+#endif
 
 extern "C" [[noreturn]] void CanSenderLoop(void *) noexcept;
 extern "C" [[noreturn]] void CanClockLoop(void *) noexcept;
@@ -239,7 +243,7 @@ void TxCallback(uint8_t marker, CanId id, uint16_t timeStamp) noexcept
 void CanInterface::Init() noexcept
 {
 	CanMessageBuffer::Init(NumCanBuffers);
-	pendingBuffers = nullptr;
+	pendingMotionBuffers = nullptr;
 
 	transactionMutex.Create("CanTrans");
 
@@ -369,13 +373,16 @@ extern "C" [[noreturn]] void CanSenderLoop(void *) noexcept
 			{
 				can0dev->SendMessage(TxBufferIndexUrgent, MaxUrgentSendWait, urgentMessage);
 			}
-			else if (pendingBuffers != nullptr)
+			else if (pendingMotionBuffers != nullptr)
 			{
 				CanMessageBuffer *buf;
 				{
 					TaskCriticalSectionLocker lock;
-					buf = pendingBuffers;
-					pendingBuffers = buf->next;
+					buf = pendingMotionBuffers;
+					pendingMotionBuffers = buf->next;
+#if 0	//unused
+					--numPendingMotionBuffers;
+#endif
 				}
 
 				// Send the message
@@ -617,20 +624,33 @@ void CanInterface::SendMotion(CanMessageBuffer *buf) noexcept
 	{
 		TaskCriticalSectionLocker lock;
 
-		if (pendingBuffers == nullptr)
+		if (pendingMotionBuffers == nullptr)
 		{
-			pendingBuffers = buf;
+			pendingMotionBuffers = buf;
 		}
 		else
 		{
-			lastBuffer->next = buf;
+			lastMotionBuffer->next = buf;
 		}
-		lastBuffer = buf;
+		lastMotionBuffer = buf;
+#if 0	//unused
+		++numPendingMotionBuffers;
+#endif
 	}
 
 	canSenderTask.Give();
 }
 
+#if 0	// not currently used
+
+// Get the number of motion messages waiting to be sent through the Tx fifo
+unsigned int CanInterface::GetNumPendingMotionMessages() noexcept
+{
+	return can0dev->NumTxMessagesPending(TxBufferIndexMotion) + numPendingMotionBuffers;
+}
+
+#endif
+
 // Send a request to an expansion board and append the response to 'reply'
 GCodeResult CanInterface::SendRequestAndGetStandardReply(CanMessageBuffer *buf, CanRequestId rid, const StringRef& reply, uint8_t *extra) noexcept
 {
diff --git a/src/CAN/CanInterface.h b/src/CAN/CanInterface.h
index 50aecfd7..8ee3b0b1 100644
--- a/src/CAN/CanInterface.h
+++ b/src/CAN/CanInterface.h
@@ -106,6 +106,9 @@ namespace CanInterface
 	GCodeResult SetRemoteDriverStepsPerMmAndMicrostepping(const CanDriversData<StepsPerUnitAndMicrostepping>& data, const StringRef& reply) noexcept;
 	GCodeResult ConfigureRemoteDriver(DriverId driver, GCodeBuffer& gb, const StringRef& reply) THROWS(GCodeException);
 	GCodeResult GetSetRemoteDriverStallParameters(const CanDriversList& drivers, GCodeBuffer& gb, const StringRef& reply, OutputBuffer *& buf) THROWS(GCodeException);
+#if 0	// not currently used
+	unsigned int GetNumPendingMotionMessages() noexcept;
+#endif
 	void WakeAsyncSenderFromIsr() noexcept;
 
 	// Remote handle functions
diff --git a/src/CAN/CanMotion.cpp b/src/CAN/CanMotion.cpp
index 6c8e72b6..c1c82dc2 100644
--- a/src/CAN/CanMotion.cpp
+++ b/src/CAN/CanMotion.cpp
@@ -17,6 +17,10 @@ static CanMessageBuffer *movementBufferList = nullptr;
 static CanMessageBuffer *urgentMessageBuffer = nullptr;
 static uint32_t currentMoveClocks;
 
+#if 0
+static unsigned int numMotionMessagesSentLast = 0;
+#endif
+
 static volatile uint32_t hiccupToInsert = 0;
 static CanDriversList driversToStop[2];
 static size_t driversToStopIndexBeingFilled = 0;
@@ -128,6 +132,9 @@ uint32_t CanMotion::FinishMovement(uint32_t moveStartTime) noexcept
 		return 0;
 	}
 
+#if 0
+	numMotionMessagesSentLast = 0;
+#endif
 	do
 	{
 		boardsActiveInLastMove.SetBit(buf->id.Dst());					//TODO should we set this if there were no steps for drives on the board, just drives to be enabled?
@@ -138,6 +145,9 @@ uint32_t CanMotion::FinishMovement(uint32_t moveStartTime) noexcept
 		buf->dataLength = buf->msg.moveLinear.GetActualDataLength();
 		CanMessageBuffer * const nextBuffer = buf->next;				// must get this before sending the buffer, because sending the buffer releases it
 		CanInterface::SendMotion(buf);									// queues the buffer for sending and frees it when done
+#if 0
+		++numMotionMessagesSentLast;
+#endif
 		buf = nextBuffer;
 	} while (buf != nullptr);
 
diff --git a/src/Fans/LocalFan.h b/src/Fans/LocalFan.h
index 469053a7..7178833f 100644
--- a/src/Fans/LocalFan.h
+++ b/src/Fans/LocalFan.h
@@ -46,7 +46,7 @@ private:
 	float lastVal;											// the last PWM value we sent to the fan, not allowing for blipping, or -1 if we don't know it
 
 	// Variables used to read the tacho
-	static constexpr uint32_t fanMaxInterruptCount = 32;	// number of fan interrupts that we average over
+	static constexpr uint32_t fanMaxInterruptCount = 16;	// number of fan interrupts that we average over. We time out after 3 seconds, so a count of 16 allows us to read rpm down to (16/3) * (60/2) = 160.
 	uint32_t fanInterruptCount;								// accessed only in ISR, so no need to declare it volatile
 	volatile uint32_t fanLastResetTime;						// time (in step clocks) at which we last reset the interrupt count, accessed inside and outside ISR
 	volatile uint32_t fanInterval;							// written by ISR, read outside the ISR
diff --git a/src/GCodes/GCodeBuffer/StringParser.cpp b/src/GCodes/GCodeBuffer/StringParser.cpp
index abf822e5..8b4df0f0 100644
--- a/src/GCodes/GCodeBuffer/StringParser.cpp
+++ b/src/GCodes/GCodeBuffer/StringParser.cpp
@@ -266,7 +266,7 @@ bool StringParser::Put(char c) noexcept
 
 // This is called when we are fed a null, CR or LF character.
 // Return true if there is a completed command ready to be executed.
-bool StringParser::LineFinished()
+bool StringParser::LineFinished() noexcept
 {
 	if (hadLineNumber)
 	{
@@ -1486,9 +1486,21 @@ void StringParser::PrintCommand(const StringRef& s) const noexcept
 }
 
 // Append the full command content to a string
+// This is called when we report a "Bad command" error, so make sure we display any control characters.
 void StringParser::AppendFullCommand(const StringRef &s) const noexcept
 {
-	s.cat(gb.buffer);
+	for (size_t i = commandStart; i < commandEnd; ++i)
+	{
+		const char c = gb.buffer[i];
+		if (c < 0x20)
+		{
+			s.catf("[0x%02x]", (unsigned int)c);
+		}
+		else
+		{
+			s.cat(c);
+		}
+	}
 }
 
 // Called when we start a new file
diff --git a/src/GCodes/GCodeBuffer/StringParser.h b/src/GCodes/GCodeBuffer/StringParser.h
index a4b828fe..3e7c515b 100644
--- a/src/GCodes/GCodeBuffer/StringParser.h
+++ b/src/GCodes/GCodeBuffer/StringParser.h
@@ -92,7 +92,7 @@ private:
 
 	void AddToChecksum(char c) noexcept;
 	void StoreAndAddToChecksum(char c) noexcept;
-	bool LineFinished() THROWS(GCodeException);									// Deal with receiving end-of-line and return true if we have a command
+	bool LineFinished() noexcept;											// Deal with receiving end-of-line and return true if we have a command
 	void InternalGetQuotedString(const StringRef& str) THROWS(GCodeException)
 		pre (readPointer >= 0; gb.buffer[readPointer] == '"'; str.IsEmpty());
 	void InternalGetPossiblyQuotedString(const StringRef& str) THROWS(GCodeException)
diff --git a/src/GCodes/GCodes3.cpp b/src/GCodes/GCodes3.cpp
index ed140fb7..b48ae06b 100644
--- a/src/GCodes/GCodes3.cpp
+++ b/src/GCodes/GCodes3.cpp
@@ -38,9 +38,11 @@
 #endif
 
 #ifdef I2C_IFACE
-# include "Wire.h"
+# include <Wire.h>
 #endif
 
+#include <cctype>
+
 // Deal with G60
 GCodeResult GCodes::SavePosition(GCodeBuffer& gb, const StringRef& reply) THROWS(GCodeException)
 {
@@ -1650,29 +1652,29 @@ bool GCodes::ProcessWholeLineComment(GCodeBuffer& gb, const StringRef& reply) TH
 		"BEGIN_LAYER_OBJECT z=",	// KISSlicer (followed by Z height)
 		"HEIGHT",					// Ideamaker
 		"PRINTING",					// Ideamaker
-		"REMAINING_TIME"			// Ideamaker
+		"REMAINING_TIME",			// Ideamaker
+		"LAYER_CHANGE"				// SuperSlicer
 	};
 
 	String<StringLength100> comment;
 	gb.GetCompleteParameters(comment.GetRef());
-	const char *text = comment.c_str();
-	while (*text == ' ')
+	const char *fullText = comment.c_str();
+	while (*fullText == ' ')
 	{
-		++text;
+		++fullText;
 	}
 
 	for (size_t i = 0; i < ARRAY_SIZE(StartStrings); ++i)
 	{
-		if (StringStartsWith(text, StartStrings[i]))
+		if (StringStartsWith(fullText, StartStrings[i]))
 		{
-			text += strlen(StartStrings[i]);
-			if (*text == ' ' || *text == ':')			// need this test to avoid recognising "processName" as "process"
+			const char *text = fullText + strlen(StartStrings[i]);
+			if (!isalpha(*text) && *text != '_')			// need this test to avoid recognising "processName" as "process"
 			{
-				do
+				while (*text == ' ' || *text == ':')
 				{
 					++text;
 				}
-				while (*text == ' ' || *text == ':');
 
 				switch (i)
 				{
@@ -1717,7 +1719,7 @@ bool GCodes::ProcessWholeLineComment(GCodeBuffer& gb, const StringRef& reply) TH
 
 				case 4:		// layer (counting from 1)
 				case 5:		// layer (counting from 0)
-				case 6:		// later (counting from 0)
+				case 6:		// layer (counting from 0)
 					{
 						const char *endptr;
 						const int32_t layer = StrToI32(text, &endptr);		// IdeaMaker uses negative layer numbers for the raft, so read a signed number here
@@ -1756,6 +1758,10 @@ bool GCodes::ProcessWholeLineComment(GCodeBuffer& gb, const StringRef& reply) TH
 						}
 					}
 					break;
+
+				case 11:	// LAYER_CHANGE (SuperSlicer). No layer number provided.
+					reprap.GetPrintMonitor().LayerChange();
+					break;
 				}
 				break;
 			}
diff --git a/src/Heating/RemoteHeater.cpp b/src/Heating/RemoteHeater.cpp
index e4cf368d..8bdfe5f3 100644
--- a/src/Heating/RemoteHeater.cpp
+++ b/src/Heating/RemoteHeater.cpp
@@ -385,7 +385,14 @@ GCodeResult RemoteHeater::SwitchOn(const StringRef& reply) noexcept
 	msg->heaterNumber = GetHeaterNumber();
 	msg->setPoint = GetTargetTemperature();
 	msg->command = CanMessageSetHeaterTemperature::commandOn;
-	return CanInterface::SendRequestAndGetStandardReply(buf, rid, reply);
+	const GCodeResult rslt = CanInterface::SendRequestAndGetStandardReply(buf, rid, reply);
+	if (lastMode == HeaterMode::off && rslt <= GCodeResult::warning)
+	{
+		// If the heater was previously off then we need to change lastMode, otherwise if M116 is executed before we get an update from the expansion board
+		// then it will treat the heater as inactive and not wait for it to reach temperature
+		lastMode = HeaterMode::heating;
+	}
+	return rslt;
 }
 
 // This is called when the heater model has been updated
diff --git a/src/Movement/DDA.cpp b/src/Movement/DDA.cpp
index 5870f59c..89959ee0 100644
--- a/src/Movement/DDA.cpp
+++ b/src/Movement/DDA.cpp
@@ -1576,7 +1576,7 @@ void DDA::Prepare(uint8_t simMode, float extrusionPending[]) noexcept
 		const DDAState st = prev->state;
 		afterPrepare.moveStartTime = (st == DDAState::executing || st == DDAState::frozen)
 						? prev->afterPrepare.moveStartTime + prev->clocksNeeded			// this move will follow the previous one, so calculate the start time assuming no more hiccups
-							: StepTimer::GetTimerTicks() + MovementStartDelayClocks;	// else this move is the first so start it after a short delay
+							: StepTimer::GetTimerTicks() + AbsoluteMinimumPreparedTime;	// else this move is the first so start it after a short delay
 
 		if (flags.checkEndstops)
 		{
diff --git a/src/Movement/DDA.h b/src/Movement/DDA.h
index 22c65780..3db44ded 100644
--- a/src/Movement/DDA.h
+++ b/src/Movement/DDA.h
@@ -113,6 +113,7 @@ public:
 
 #if SUPPORT_LASER || SUPPORT_IOBITS
 	LaserPwmOrIoBits GetLaserPwmOrIoBits() const noexcept { return laserPwmOrIoBits; }
+	bool ControlLaser() const noexcept { return flags.controlLaser; }
 #endif
 
 #if SUPPORT_LASER
@@ -135,6 +136,8 @@ public:
 	void DebugPrint(const char *tag) const noexcept;								// print the DDA only
 	void DebugPrintAll(const char *tag) const noexcept;								// print the DDA and active DMs
 
+	static void PrintMoves() noexcept;												// print saved moves for debugging
+
 	// Note on the following constant:
 	// If we calculate the step interval on every clock, we reach a point where the calculation time exceeds the step interval.
 	// The worst case is pure Z movement on a delta. On a Mini Kossel with 80 steps/mm with this firmware running on a Duet (84MHx SAM3X8 processor),
@@ -163,7 +166,8 @@ public:
 	static constexpr uint32_t WakeupTime = (100 * StepTimer::StepClockRate)/1000000;				// stop resting 100us before the move is due to end
 	static constexpr uint32_t HiccupIncrement = HiccupTime/2;										// how much we increase the hiccup time by on each attempt
 
-	static void PrintMoves() noexcept;																// print saved moves for debugging
+	static constexpr uint32_t UsualMinimumPreparedTime = StepTimer::StepClockRate/10;				// 100ms
+	static constexpr uint32_t AbsoluteMinimumPreparedTime = StepTimer::StepClockRate/20;			// 50ms
 
 #if DDA_LOG_PROBE_CHANGES
 	static const size_t MaxLoggedProbePositions = 40;
@@ -171,10 +175,6 @@ public:
 	static int32_t loggedProbePositions[XYZ_AXES * MaxLoggedProbePositions];
 #endif
 
-#if SUPPORT_LASER || SUPPORT_IOBITS
-	bool ControlLaser() const noexcept { return flags.controlLaser; }
-#endif
-
 	static uint32_t lastStepLowTime;										// when we last completed a step pulse to a slow driver
 	static uint32_t lastDirChangeTime;										// when we last change the DIR signal to a slow driver
 
diff --git a/src/Movement/DDARing.cpp b/src/Movement/DDARing.cpp
index cb765e53..11108208 100644
--- a/src/Movement/DDARing.cpp
+++ b/src/Movement/DDARing.cpp
@@ -15,9 +15,6 @@
 # include "CAN/CanMotion.h"
 #endif
 
-constexpr uint32_t UsualMinimumPreparedTime = StepTimer::StepClockRate/10;			// 100ms
-constexpr uint32_t AbsoluteMinimumPreparedTime = StepTimer::StepClockRate/20;		// 50ms
-
 // Object model table and functions
 // Note: if using GCC version 7.3.1 20180622 and lambda functions are used in this table, you must compile this file with option -std=gnu++17.
 // Otherwise the table will be allocated in RAM instead of flash, which wastes too much RAM.
@@ -357,9 +354,9 @@ void DDARing::PrepareMoves(DDA *firstUnpreparedMove, int32_t moveTimeLeft, unsig
 	// If the number of prepared moves will execute in less than the minimum time, prepare another move.
 	// Try to avoid preparing deceleration-only moves too early
 	while (	  firstUnpreparedMove->GetState() == DDA::provisional
-		   && moveTimeLeft < (int32_t)UsualMinimumPreparedTime		// prepare moves one eighth of a second ahead of when they will be needed
+		   && moveTimeLeft < (int32_t)DDA::UsualMinimumPreparedTime		// prepare moves one tenth of a second ahead of when they will be needed
 		   && alreadyPrepared * 2 < numDdasInRing					// but don't prepare more than half the ring
-		   && (firstUnpreparedMove->IsGoodToPrepare() || moveTimeLeft < (int32_t)AbsoluteMinimumPreparedTime)
+		   && (firstUnpreparedMove->IsGoodToPrepare() || moveTimeLeft < (int32_t)DDA::AbsoluteMinimumPreparedTime)
 #if SUPPORT_CAN_EXPANSION
 		   && CanMotion::CanPrepareMove()
 #endif
diff --git a/src/Platform/TaskPriorities.h b/src/Platform/TaskPriorities.h
index b65f1568..36545a55 100644
--- a/src/Platform/TaskPriorities.h
+++ b/src/Platform/TaskPriorities.h
@@ -14,7 +14,7 @@ namespace TaskPriority
 	constexpr int IdlePriority = 0;
 	constexpr int SpinPriority = 1;							// priority for tasks that rarely block
 #if HAS_LINUX_INTERFACE
-	constexpr int SbcPriority = 1;							// priority for SBC task
+	constexpr int SbcPriority = 1;							// priority for SBC task. TODO increase this when we are certain that it never spins.
 #endif
 #if defined(LPC_NETWORKING)
     constexpr int TcpPriority  = 2;
@@ -26,7 +26,9 @@ namespace TaskPriority
 	constexpr int TmcPriority = 4;
 	constexpr int AinPriority = 4;
 	constexpr int HeightFollowingPriority = 4;
+#ifdef DUET_NG
 	constexpr int DueXPriority = 5;
+#endif
 	constexpr int LaserPriority = 5;
 	constexpr int CanSenderPriority = 5;
 	constexpr int CanReceiverPriority = 5;
diff --git a/src/PrintMonitor/PrintMonitor.cpp b/src/PrintMonitor/PrintMonitor.cpp
index 64661cb9..4cf8f2ed 100644
--- a/src/PrintMonitor/PrintMonitor.cpp
+++ b/src/PrintMonitor/PrintMonitor.cpp
@@ -346,6 +346,14 @@ void PrintMonitor::SetLayerZ(float layerZ) noexcept
 	// Currently we don't use the layerZ value
 }
 
+// Report that a new layer has started
+void PrintMonitor::LayerChange() noexcept
+{
+	++currentLayer;
+	lastLayerChangeTime = millis64();
+	lastLayerChangeNonPrintingTime = GetWarmUpDuration() + GetPauseDuration();
+}
+
 float PrintMonitor::FractionOfFilePrinted() const noexcept
 {
 	ReadLocker locker(printMonitorLock);
diff --git a/src/PrintMonitor/PrintMonitor.h b/src/PrintMonitor/PrintMonitor.h
index 16ae6b62..5ff5406f 100644
--- a/src/PrintMonitor/PrintMonitor.h
+++ b/src/PrintMonitor/PrintMonitor.h
@@ -44,6 +44,7 @@ public:
 	void StoppedPrint() noexcept;							// Called whenever a file print has stopped
 	void SetLayerNumber(uint32_t layerNumber) noexcept;		// Set the current layer number
 	void SetLayerZ(float layerZ) noexcept;					// Set the printing height of the new layer
+	void LayerChange() noexcept;							// Report that a new layer has started
 	float FractionOfFilePrinted() const noexcept;			// Return the fraction printed (0..1)
 
 	// Return an estimate in seconds based on a specific estimation method
diff --git a/src/Version.h b/src/Version.h
index f31ac080..f1076245 100644
--- a/src/Version.h
+++ b/src/Version.h
@@ -9,7 +9,7 @@
 #define SRC_VERSION_H_
 
 #ifndef VERSION
-# define MAIN_VERSION	"3.3RC3+6"
+# define MAIN_VERSION	"3.3RC3+7"
 # ifdef USE_CAN0
 #  define VERSION_SUFFIX	" (CAN0)"
 # else