More work on remote heater tuning

10 files changed, 370 insertions, 165 deletions

diff --git a/src/CAN/CommandProcessor.cpp b/src/CAN/CommandProcessor.cpp
index 86936b56..38635bd4 100644
--- a/src/CAN/CommandProcessor.cpp
+++ b/src/CAN/CommandProcessor.cpp
@@ -515,6 +515,10 @@ void CommandProcessor::ProcessReceivedMessage(CanMessageBuffer *buf) noexcept
 				reprap.GetHeat().ProcessRemoteHeatersReport(buf->id.Src(), buf->msg.heatersStatusBroadcast);
 				break;
 
+			case CanMessageType::heaterTuningReport:
+				reprap.GetHeat().ProcessRemoteHeaterTuningReport(buf->id.Src(), buf->msg.heaterTuningReport);
+				break;
+
 			case CanMessageType::fansReport:
 				reprap.GetFansManager().ProcessRemoteFanRpms(buf->id.Src(), buf->msg.fansReport);
 				break;
diff --git a/src/Heating/Heat.cpp b/src/Heating/Heat.cpp
index 89875819..6fab76b7 100644
--- a/src/Heating/Heat.cpp
+++ b/src/Heating/Heat.cpp
@@ -750,12 +750,12 @@ void Heat::Standby(int heater, const Tool *tool) noexcept
 	}
 }
 
-void Heat::PrintCoolingFanPwmChanged(unsigned int heater, float pwmChange) const noexcept
+void Heat::FeedForwardAdjustment(unsigned int heater, float fanPwmChange, float extrusionChange) const noexcept
 {
 	const auto h = FindHeater(heater);
 	if (h.IsNotNull())
 	{
-		h->PrintCoolingFanPwmChanged(pwmChange);
+		h->FeedForwardAdjustment(fanPwmChange, extrusionChange);
 	}
 }
 
@@ -1234,6 +1234,15 @@ void Heat::ProcessRemoteHeatersReport(CanAddress src, const CanMessageHeatersSta
 							);
 }
 
+void Heat::ProcessRemoteHeaterTuningReport(CanAddress src, const CanMessageHeaterTuningReport& msg) noexcept
+{
+	const auto h = FindHeater(msg.heater);
+	if (h.IsNotNull())
+	{
+		h->UpdateHeaterTuning(src, msg);
+	}
+}
+
 #endif
 
 #if SUPPORT_REMOTE_COMMANDS
diff --git a/src/Heating/Heat.h b/src/Heating/Heat.h
index 8b67f807..872c72dc 100644
--- a/src/Heating/Heat.h
+++ b/src/Heating/Heat.h
@@ -130,7 +130,7 @@ public:
 	GCodeResult Activate(int heater, const StringRef& reply) noexcept;	// Turn on a heater
 	void Standby(int heater, const Tool* tool) noexcept;				// Set a heater to standby
 	void SwitchOff(int heater) noexcept;								// Turn off a specific heater
-	void PrintCoolingFanPwmChanged(unsigned int heater, float pwmChange) const noexcept;
+	void FeedForwardAdjustment(unsigned int heater, float fanPwmChange, float extrusionChange) const noexcept;
 
 #if HAS_MASS_STORAGE
 	bool WriteModelParameters(FileStore *f) const noexcept;				// Write heater model parameters to file returning true if no error
@@ -140,6 +140,7 @@ public:
 #if SUPPORT_CAN_EXPANSION
 	void ProcessRemoteSensorsReport(CanAddress src, const CanMessageSensorTemperatures& msg) noexcept;
 	void ProcessRemoteHeatersReport(CanAddress src, const CanMessageHeatersStatus& msg) noexcept;
+	void ProcessRemoteHeaterTuningReport(CanAddress src, const CanMessageHeaterTuningReport& msg) noexcept;
 #endif
 
 #if SUPPORT_REMOTE_COMMANDS
diff --git a/src/Heating/Heater.cpp b/src/Heating/Heater.cpp
index d3bd47f5..a0d582e7 100644
--- a/src/Heating/Heater.cpp
+++ b/src/Heating/Heater.cpp
@@ -11,6 +11,7 @@
 #include "Heat.h"
 #include "HeaterMonitor.h"
 #include "Sensors/TemperatureSensor.h"
+#include <GCodes/GCodes.h>
 #include <GCodes/GCodeBuffer/GCodeBuffer.h>
 #include <GCodes/GCodeException.h>
 
@@ -64,14 +65,17 @@ DEFINE_GET_OBJECT_MODEL_TABLE(Heater)
 
 float Heater::tuningPwm;								// the PWM to use, 0..1
 float Heater::tuningTargetTemp;							// the target temperature
+
 DeviationAccumulator Heater::tuningStartTemp;			// the temperature when we turned on the heater
-uint32_t Heater::tuningBeginTime;						// when we started the tuning process
 DeviationAccumulator Heater::dHigh;
 DeviationAccumulator Heater::dLow;
 DeviationAccumulator Heater::tOn;
 DeviationAccumulator Heater::tOff;
 DeviationAccumulator Heater::heatingRate;
 DeviationAccumulator Heater::coolingRate;
+DeviationAccumulator Heater::tuningVoltage;				// sum of the voltage readings we take during the heating phase
+
+uint32_t Heater::tuningBeginTime;						// when we started the tuning process
 uint32_t Heater::lastOffTime;
 uint32_t Heater::lastOnTime;
 float Heater::peakTemp;									// max or min temperature
@@ -83,6 +87,8 @@ FansBitmap Heater::tuningFans;
 unsigned int Heater::tuningPhase;
 uint8_t Heater::idleCyclesDone;
 
+Heater::HeaterParameters Heater::fanOffParams, Heater::fanOnParams;
+
 // Clear all the counters except tuning voltage and start temperature
 /*static*/ void Heater::ClearCounters() noexcept
 {
@@ -292,6 +298,116 @@ GCodeResult Heater::StartAutoTune(GCodeBuffer& gb, const StringRef& reply, FansB
 	return rslt;
 }
 
+// Get the auto tune status or last result
+void Heater::GetAutoTuneStatus(const StringRef& reply) const noexcept
+{
+	if (GetStatus() == HeaterStatus::tuning)
+	{
+		// Phases are: 1 = stabilising, 2 = heating, 3 = settling, 4 = cycling with fan off, 5 = cycling with fan on
+		const unsigned int numPhases = (tuningFans.IsEmpty()) ? 4
+#if TUNE_WITH_HALF_FAN
+				: 6;
+#else
+				: 5;
+#endif
+		reply.printf("Heater %u is being tuned, phase %u of %u", GetHeaterNumber(), tuningPhase, numPhases);
+	}
+	else if (tuned)
+	{
+		reply.printf("Heater %u tuning succeeded, use M307 H%u to see result", GetHeaterNumber(), GetHeaterNumber());
+	}
+	else
+	{
+		reply.printf("Heater %u tuning failed", GetHeaterNumber());
+	}
+}
+
+void Heater::CalculateModel(HeaterParameters& params) noexcept
+{
+	if (reprap.Debug(moduleHeat))
+	{
+#define PLUS_OR_MINUS "\xC2\xB1"
+		reprap.GetPlatform().MessageF(GenericMessage,
+										"tOn %ld" PLUS_OR_MINUS "%ld, tOff %ld" PLUS_OR_MINUS "%ld,"
+										" dHigh %ld" PLUS_OR_MINUS "%ld, dLow %ld" PLUS_OR_MINUS "%ld,"
+										" R %.3f" PLUS_OR_MINUS "%.3f, C %.3f" PLUS_OR_MINUS "%.3f,"
+#if HAS_VOLTAGE_MONITOR
+										" V %.1f" PLUS_OR_MINUS "%.1f,"
+#endif
+										" cycles %u\n",
+										lrintf(tOn.GetMean()), lrintf(tOn.GetDeviation()),
+										lrintf(tOff.GetMean()), lrintf(tOff.GetDeviation()),
+										lrintf(dHigh.GetMean()), lrintf(dHigh.GetDeviation()),
+										lrintf(dLow.GetMean()), lrintf(dLow.GetDeviation()),
+										(double)heatingRate.GetMean(), (double)heatingRate.GetDeviation(),
+										(double)coolingRate.GetMean(), (double)coolingRate.GetDeviation(),
+#if HAS_VOLTAGE_MONITOR
+										(double)tuningVoltage.GetMean(), (double)tuningVoltage.GetDeviation(),
+#endif
+										coolingRate.GetNumSamples()
+									 );
+	}
+
+	const float cycleTime = tOn.GetMean() + tOff.GetMean();		// in milliseconds
+	const float averageTemperatureRiseHeating = tuningTargetTemp - 0.5 * (TuningHysteresis - TuningPeakTempDrop) - tuningStartTemp.GetMean();
+	const float averageTemperatureRiseCooling = tuningTargetTemp - TuningPeakTempDrop - 0.5 * TuningHysteresis - tuningStartTemp.GetMean();
+	params.deadTime = (((dHigh.GetMean() * tOff.GetMean()) + (dLow.GetMean() * tOn.GetMean())) * MillisToSeconds)/cycleTime;	// in seconds
+	params.coolingRate = coolingRate.GetMean()/averageTemperatureRiseCooling;			// in seconds
+	params.heatingRate = (heatingRate.GetMean() + (coolingRate.GetMean() * averageTemperatureRiseHeating/averageTemperatureRiseCooling)) / tuningPwm;
+	params.numCycles = dHigh.GetNumSamples();
+}
+
+void Heater::SetAndReportModel(bool usingFans) noexcept
+{
+	const float hRate = (usingFans) ? (fanOffParams.heatingRate + fanOnParams.heatingRate) * 0.5 : fanOffParams.heatingRate;
+	const float deadTime = (usingFans) ? (fanOffParams.deadTime + fanOnParams.deadTime) * 0.5 : fanOffParams.deadTime;
+	const float fanOnCoolingRate = (usingFans) ? fanOnParams.coolingRate : fanOffParams.coolingRate;
+	String<StringLength256> str;
+	const GCodeResult rslt = SetModel(	hRate,
+										fanOffParams.coolingRate, fanOnCoolingRate,
+										deadTime,
+										tuningPwm,
+#if HAS_VOLTAGE_MONITOR
+										tuningVoltage.GetMean(),
+#else
+										0.0,
+#endif
+										true, false, str.GetRef());
+	if (rslt == GCodeResult::ok || rslt == GCodeResult::warning)
+	{
+		tuned = true;
+		str.printf("Auto tuning heater %u completed after %u idle and %u tuning cycles in %" PRIu32 " seconds. This heater needs the following M307 command:\n"
+					" M307 H%u R%.3f C%.1f",
+					GetHeaterNumber(),
+					idleCyclesDone,
+					(usingFans) ? fanOffParams.numCycles + fanOnParams.numCycles : fanOffParams.numCycles,
+					(millis() - tuningBeginTime)/(uint32_t)SecondsToMillis,
+					GetHeaterNumber(), (double)GetModel().GetHeatingRate(), (double)(1.0/GetModel().GetCoolingRateFanOff())
+				  );
+		if (usingFans)
+		{
+			str.catf(":%.1f", (double)(1.0/GetModel().GetCoolingRateFanOn()));
+		}
+		str.catf(" D%.2f S%.2f V%.1f\n", (double)GetModel().GetDeadTime(), (double)GetModel().GetMaxPwm(), (double)GetModel().GetVoltage());
+		reprap.GetPlatform().Message(LoggedGenericMessage, str.c_str());
+		if (reprap.GetGCodes().SawM501InConfigFile())
+		{
+			reprap.GetPlatform().Message(GenericMessage, "Send M500 to save this command in config-override.g\n");
+		}
+		else
+		{
+			reprap.GetPlatform().MessageF(GenericMessage, "Edit the M307 H%u command in config.g to match this. Omit the V parameter if the heater is not powered from VIN.\n", GetHeaterNumber());
+		}
+	}
+	else
+	{
+		reprap.GetPlatform().MessageF(WarningMessage, "Auto tune of heater %u failed due to bad curve fit (R=%.3f, 1/C=%.4f:%.4f, D=%.1f)\n",
+										GetHeaterNumber(), (double)hRate,
+										(double)fanOffParams.coolingRate, (double)fanOnCoolingRate,
+										(double)fanOffParams.deadTime);
+	}
+}
+
 GCodeResult Heater::SetFaultDetectionParameters(float pMaxTempExcursion, float pMaxFaultTime, const StringRef& reply) noexcept
 {
 	maxTempExcursion = pMaxTempExcursion;
diff --git a/src/Heating/Heater.h b/src/Heating/Heater.h
index 4600ab0c..d1719a2f 100644
--- a/src/Heating/Heater.h
+++ b/src/Heating/Heater.h
@@ -20,7 +20,10 @@
 # include "CanId.h"
 #endif
 
+#define TUNE_WITH_HALF_FAN	0
+
 class HeaterMonitor;
+struct CanMessageHeaterTuningReport;
 struct CanHeaterReport;
 
 // Enumeration to describe the status of a heater. Note that the web interface returns the numerical values, so don't change them.
@@ -43,13 +46,13 @@ public:
 	virtual GCodeResult ResetFault(const StringRef& reply) noexcept = 0;	// Reset a fault condition - only call this if you know what you are doing
 	virtual void SwitchOff() noexcept = 0;
 	virtual void Spin() noexcept = 0;
-	virtual void GetAutoTuneStatus(const StringRef& reply) const noexcept = 0;	// Get the auto tune status or last result
 	virtual void Suspend(bool sus) noexcept = 0;						// Suspend the heater to conserve power or while doing Z probing
 	virtual float GetAccumulator() const noexcept = 0;					// Get the inertial term accumulator
-	virtual void PrintCoolingFanPwmChanged(float pwmChange) noexcept = 0;
+	virtual void FeedForwardAdjustment(float fanPwmChange, float extrusionChange) noexcept = 0;
 
 #if SUPPORT_CAN_EXPANSION
 	virtual void UpdateRemoteStatus(CanAddress src, const CanHeaterReport& report) noexcept = 0;
+	virtual void UpdateHeaterTuning(CanAddress src, const CanMessageHeaterTuningReport& msg) noexcept = 0;
 #endif
 
 	HeaterStatus GetStatus() const noexcept;							// Get the status of the heater
@@ -61,6 +64,7 @@ public:
 	GCodeResult Activate(const StringRef& reply) noexcept;				// Switch from idle to active
 	void Standby() noexcept;											// Switch from active to idle
 	GCodeResult StartAutoTune(GCodeBuffer& gb, const StringRef& reply, FansBitmap fans) THROWS(GCodeException);	// Start an auto tune cycle for this heater
+	void GetAutoTuneStatus(const StringRef& reply) const noexcept;		// Get the auto tune status or last result
 
 	void GetFaultDetectionParameters(float& pMaxTempExcursion, float& pMaxFaultTime) const noexcept
 		{ pMaxTempExcursion = maxTempExcursion; pMaxFaultTime = maxHeatingFaultTime; }
@@ -107,7 +111,14 @@ protected:
 		lastTuningMode = tuning3
 	};
 
-protected:
+	struct HeaterParameters
+	{
+		float heatingRate;
+		float coolingRate;
+		float deadTime;
+		unsigned int numCycles;
+	};
+
 	virtual void ResetHeater() noexcept = 0;
 	virtual HeaterMode GetMode() const noexcept = 0;
 	virtual GCodeResult SwitchOn(const StringRef& reply) noexcept = 0;
@@ -121,7 +132,10 @@ protected:
 	float GetMaxTemperatureExcursion() const noexcept { return maxTempExcursion; }
 	float GetMaxHeatingFaultTime() const noexcept { return maxHeatingFaultTime; }
 	float GetTargetTemperature() const noexcept { return (active) ? activeTemperature : standbyTemperature; }
-	GCodeResult SetModel(float hr, float coolingRateFanOff, float coolingRateFanOn, float td, float maxPwm, float voltage, bool usePid, bool inverted, const StringRef& reply) noexcept;	// Set the process model
+	GCodeResult SetModel(float hr, float coolingRateFanOff, float coolingRateFanOn, float td, float maxPwm, float voltage, bool usePid, bool inverted, const StringRef& reply) noexcept;
+															// set the process model
+	void CalculateModel(HeaterParameters& params) noexcept;	// calculate G, td and tc from the accumulated readings
+	void SetAndReportModel(bool usingFans) noexcept;
 
 	HeaterMonitor monitors[MaxMonitorsPerHeater];			// embedding them in the Heater uses less memory than dynamic allocation
 	bool tuned;												// true if tuning was successful
@@ -148,6 +162,8 @@ protected:
 	static DeviationAccumulator tOff;
 	static DeviationAccumulator heatingRate;
 	static DeviationAccumulator coolingRate;
+	static DeviationAccumulator tuningVoltage;				// sum of the voltage readings we take during the heating phase
+
 	static uint32_t lastOffTime;
 	static uint32_t lastOnTime;
 	static float peakTemp;									// max or min temperature
@@ -159,6 +175,8 @@ protected:
 	static unsigned int tuningPhase;
 	static uint8_t idleCyclesDone;
 
+	static HeaterParameters fanOffParams, fanOnParams;
+
 	static void ClearCounters() noexcept;
 
 private:
diff --git a/src/Heating/LocalHeater.cpp b/src/Heating/LocalHeater.cpp
index 9a5db5c9..e9da73ab 100644
--- a/src/Heating/LocalHeater.cpp
+++ b/src/Heating/LocalHeater.cpp
@@ -14,14 +14,6 @@
 #include "RepRap.h"
 #include <Tools/Tool.h>
 
-#define TUNE_WITH_HALF_FAN	0
-
-static LocalHeater::HeaterParameters fanOffParams, fanOnParams;
-
-#if HAS_VOLTAGE_MONITOR
-static DeviationAccumulator tuningVoltage;				// sum of the voltage readings we take during the heating phase
-#endif
-
 // Member functions and constructors
 
 LocalHeater::LocalHeater(unsigned int heaterNum) noexcept : Heater(heaterNum), mode(HeaterMode::off)
@@ -474,36 +466,12 @@ GCodeResult LocalHeater::StartAutoTune(const StringRef& reply, FansBitmap fans,
 	return GCodeResult::ok;
 }
 
-// Get the auto tune status or last result
-void LocalHeater::GetAutoTuneStatus(const StringRef& reply) const noexcept
-{
-	if (mode >= HeaterMode::tuning0)
-	{
-		// Phases are: 1 = stabilising, 2 = heating, 3 = settling, 4 = cycling with fan off, 5 = cycling with fan on
-		const unsigned int numPhases = (tuningFans.IsEmpty()) ? 4
-#if TUNE_WITH_HALF_FAN
-				: 6;
-#else
-				: 5;
-#endif
-		reply.printf("Heater %u is being tuned, phase %u of %u", GetHeaterNumber(), tuningPhase + 1, numPhases);
-	}
-	else if (tuned)
-	{
-		reply.printf("Heater %u tuning succeeded, use M307 H%u to see result", GetHeaterNumber(), GetHeaterNumber());
-	}
-	else
-	{
-		reply.printf("Heater %u tuning failed", GetHeaterNumber());
-	}
-}
-
 // Call this when the PWM of a cooling fan has changed. If there are multiple fans, caller must divide pwmChange by the number of fans.
-void LocalHeater::PrintCoolingFanPwmChanged(float pwmChange) noexcept
+void LocalHeater::FeedForwardAdjustment(float fanPwmChange, float extrusionChange) noexcept
 {
 	if (mode == HeaterMode::stable)
 	{
-		const float coolingRateIncrease = GetModel().GetCoolingRateChangeFanOn() * pwmChange;
+		const float coolingRateIncrease = GetModel().GetCoolingRateChangeFanOn() * fanPwmChange;
 		const float boost = (coolingRateIncrease * (GetTargetTemperature() - NormalAmbientTemperature) * FeedForwardMultiplier)/GetModel().GetHeatingRate();
 #if 0
 		if (reprap.Debug(moduleHeat))
@@ -610,9 +578,7 @@ void LocalHeater::DoTuningStep() noexcept
 				SetHeater(0.0);
 				peakTemp = afterPeakTemp = temperature;
 				lastOffTime = peakTime = afterPeakTime = now;
-#if HAS_VOLTAGE_MONITOR
 				tuningVoltage.Clear();
-#endif
 				idleCyclesDone = 0;
 				mode = HeaterMode::tuning2;
 				tuningPhase = 2;
@@ -757,92 +723,6 @@ void LocalHeater::DoTuningStep() noexcept
 }
 
 // Calculate the heater model from the accumulated heater parameters
-void LocalHeater::CalculateModel(HeaterParameters& params) noexcept
-{
-	if (reprap.Debug(moduleHeat))
-	{
-#define PLUS_OR_MINUS "\xC2\xB1"
-		reprap.GetPlatform().MessageF(GenericMessage,
-										"tOn %ld" PLUS_OR_MINUS "%ld, tOff %ld" PLUS_OR_MINUS "%ld,"
-										" dHigh %ld" PLUS_OR_MINUS "%ld, dLow %ld" PLUS_OR_MINUS "%ld,"
-										" R %.3f" PLUS_OR_MINUS "%.3f, C %.3f" PLUS_OR_MINUS "%.3f,"
-#if HAS_VOLTAGE_MONITOR
-										" V %.1f" PLUS_OR_MINUS "%.1f,"
-#endif
-										" cycles %u\n",
-										lrintf(tOn.GetMean()), lrintf(tOn.GetDeviation()),
-										lrintf(tOff.GetMean()), lrintf(tOff.GetDeviation()),
-										lrintf(dHigh.GetMean()), lrintf(dHigh.GetDeviation()),
-										lrintf(dLow.GetMean()), lrintf(dLow.GetDeviation()),
-										(double)heatingRate.GetMean(), (double)heatingRate.GetDeviation(),
-										(double)coolingRate.GetMean(), (double)coolingRate.GetDeviation(),
-#if HAS_VOLTAGE_MONITOR
-										(double)tuningVoltage.GetMean(), (double)tuningVoltage.GetDeviation(),
-#endif
-										coolingRate.GetNumSamples()
-									 );
-	}
-
-	const float cycleTime = tOn.GetMean() + tOff.GetMean();		// in milliseconds
-	const float averageTemperatureRiseHeating = tuningTargetTemp - 0.5 * (TuningHysteresis - TuningPeakTempDrop) - tuningStartTemp.GetMean();
-	const float averageTemperatureRiseCooling = tuningTargetTemp - TuningPeakTempDrop - 0.5 * TuningHysteresis - tuningStartTemp.GetMean();
-	params.deadTime = (((dHigh.GetMean() * tOff.GetMean()) + (dLow.GetMean() * tOn.GetMean())) * MillisToSeconds)/cycleTime;	// in seconds
-	params.coolingRate = coolingRate.GetMean()/averageTemperatureRiseCooling;			// in seconds
-	params.heatingRate = (heatingRate.GetMean() + (coolingRate.GetMean() * averageTemperatureRiseHeating/averageTemperatureRiseCooling)) / tuningPwm;
-	params.numCycles = dHigh.GetNumSamples();
-}
-
-void LocalHeater::SetAndReportModel(bool usingFans) noexcept
-{
-	const float hRate = (usingFans) ? (fanOffParams.heatingRate + fanOnParams.heatingRate) * 0.5 : fanOffParams.heatingRate;
-	const float deadTime = (usingFans) ? (fanOffParams.deadTime + fanOnParams.deadTime) * 0.5 : fanOffParams.deadTime;
-	const float fanOnCoolingRate = (usingFans) ? fanOnParams.coolingRate : fanOffParams.coolingRate;
-	String<StringLength256> str;
-	const GCodeResult rslt = SetModel(	hRate,
-										fanOffParams.coolingRate, fanOnCoolingRate,
-										deadTime,
-										tuningPwm,
-#if HAS_VOLTAGE_MONITOR
-										tuningVoltage.GetMean(),
-#else
-										0.0,
-#endif
-										true, false, str.GetRef());
-	if (rslt == GCodeResult::ok || rslt == GCodeResult::warning)
-	{
-		tuned = true;
-		str.printf("Auto tuning heater %u completed after %u idle and %u tuning cycles in %" PRIu32 " seconds. This heater needs the following M307 command:\n"
-					" M307 H%u R%.3f C%.1f",
-					GetHeaterNumber(),
-					idleCyclesDone,
-					(usingFans) ? fanOffParams.numCycles + fanOnParams.numCycles : fanOffParams.numCycles,
-					(millis() - tuningBeginTime)/(uint32_t)SecondsToMillis,
-					GetHeaterNumber(), (double)GetModel().GetHeatingRate(), (double)(1.0/GetModel().GetCoolingRateFanOff())
-				  );
-		if (usingFans)
-		{
-			str.catf(":%.1f", (double)(1.0/GetModel().GetCoolingRateFanOn()));
-		}
-		str.catf(" D%.2f S%.2f V%.1f\n", (double)GetModel().GetDeadTime(), (double)GetModel().GetMaxPwm(), (double)GetModel().GetVoltage());
-		reprap.GetPlatform().Message(LoggedGenericMessage, str.c_str());
-		if (reprap.GetGCodes().SawM501InConfigFile())
-		{
-			reprap.GetPlatform().Message(GenericMessage, "Send M500 to save this command in config-override.g\n");
-		}
-		else
-		{
-			reprap.GetPlatform().MessageF(GenericMessage, "Edit the M307 H%u command in config.g to match this. Omit the V parameter if the heater is not powered from VIN.\n", GetHeaterNumber());
-		}
-	}
-	else
-	{
-		reprap.GetPlatform().MessageF(WarningMessage, "Auto tune of heater %u failed due to bad curve fit (R=%.3f, 1/C=%.4f:%.4f, D=%.1f)\n",
-										GetHeaterNumber(), (double)hRate,
-										(double)fanOffParams.coolingRate, (double)fanOnCoolingRate,
-										(double)fanOffParams.deadTime);
-	}
-}
-
 // Suspend the heater, or resume it
 void LocalHeater::Suspend(bool sus) noexcept
 {
diff --git a/src/Heating/LocalHeater.h b/src/Heating/LocalHeater.h
index 80afa0ad..02fde4f9 100644
--- a/src/Heating/LocalHeater.h
+++ b/src/Heating/LocalHeater.h
@@ -25,14 +25,6 @@ class LocalHeater : public Heater
 	static const size_t NumPreviousTemperatures = 4;		// How many samples we average the temperature derivative over
 
 public:
-	struct HeaterParameters
-	{
-		float heatingRate;
-		float coolingRate;
-		float deadTime;
-		unsigned int numCycles;
-	};
-
 	LocalHeater(unsigned int heaterNum) noexcept;
 	~LocalHeater() noexcept;
 
@@ -46,12 +38,12 @@ public:
 	float GetTemperature() const noexcept override;							// Get the latest temperature
 	float GetAveragePWM() const noexcept override;							// Return the running average PWM to the heater. Answer is a fraction in [0, 1].
 	float GetAccumulator() const noexcept override;							// Return the integral accumulator
-	void GetAutoTuneStatus(const StringRef& reply) const noexcept override;	// Get the auto tune status or last result
 	void Suspend(bool sus) noexcept override;								// Suspend the heater to conserve power or while doing Z probing
-	void PrintCoolingFanPwmChanged(float pwmChange) noexcept override;
+	void FeedForwardAdjustment(float fanPwmChange, float extrusionChange) noexcept override;
 
 #if SUPPORT_CAN_EXPANSION
 	void UpdateRemoteStatus(CanAddress src, const CanHeaterReport& report) noexcept override { }
+	void UpdateHeaterTuning(CanAddress src, const CanMessageHeaterTuningReport& msg) noexcept override { }
 #endif
 
 protected:
@@ -67,8 +59,6 @@ private:
 	void SetHeater(float power) const noexcept;				// Power is a fraction in [0,1]
 	TemperatureError ReadTemperature() noexcept;			// Read and store the temperature of this heater
 	void DoTuningStep() noexcept;							// Called on each temperature sample when auto tuning
-	void CalculateModel(HeaterParameters& params) noexcept;	// Calculate G, td and tc from the accumulated readings
-	void SetAndReportModel(bool usingFans) noexcept;
 	float GetExpectedHeatingRate() const noexcept;			// Get the minimum heating rate we expect
 	void RaiseHeaterFault(const char *format, ...) noexcept;
 
diff --git a/src/Heating/RemoteHeater.cpp b/src/Heating/RemoteHeater.cpp
index 1620bf1d..7517ba0e 100644
--- a/src/Heating/RemoteHeater.cpp
+++ b/src/Heating/RemoteHeater.cpp
@@ -17,6 +17,12 @@
 #include <CanMessageFormats.h>
 #include <CanMessageBuffer.h>
 
+// Static variables used only during tuning
+uint32_t RemoteHeater::timeSetHeating;
+float RemoteHeater::currentCoolingRate;
+unsigned int RemoteHeater::tuningCyclesDone;
+bool RemoteHeater::newTuningResult = false;
+
 RemoteHeater::RemoteHeater(unsigned int num, CanAddress board) noexcept
 	: Heater(num), boardAddress(board), lastMode(HeaterMode::offline), averagePwm(0), tuningState(TuningState::notTuning), lastTemperature(0.0), whenLastStatusReceived(0)
 {
@@ -33,34 +39,162 @@ RemoteHeater::~RemoteHeater() noexcept
 
 void RemoteHeater::Spin() noexcept
 {
+	const uint32_t now = millis();
 	switch (tuningState)
 	{
 	case TuningState::notTuning:
 		break;
 
 	case TuningState::stabilising:
-		//TODO wait for temp to stabilise
+		if (tuningStartTemp.GetNumSamples() < 5000/HeatSampleIntervalMillis)
+		{
+			tuningStartTemp.Add(lastTemperature);						// take another reading until we have samples temperatures for 5 seconds
+		}
+		else if (tuningStartTemp.GetDeviation() <= 2.0)
 		{
+			timeSetHeating = now;
+			ClearCounters();
+			timeSetHeating = millis();
 			String<StringLength100> reply;
-			if (SendTuningCommand(reply.GetRef(), true) != GCodeResult::ok)
+			if (SendTuningCommand(reply.GetRef(), true) == GCodeResult::ok)
+			{
+				tuningState = TuningState::heatingUp;
+				tuningPhase = 1;
+				reprap.GetPlatform().Message(GenericMessage, "Auto tune starting phase 1, heater on\n");
+			}
+			else
 			{
-				reprap.GetPlatform().MessageF(ErrorMessage, "Heater tuning cancelled: %s\n", reply.c_str());
-				SwitchOff();
+				reprap.GetPlatform().Message(ErrorMessage, "Failed to start heater tuning\n");
 				tuningState = TuningState::notTuning;
 			}
 		}
+		else if (now - tuningBeginTime >= 20000)						// allow up to 20 seconds for starting temperature to settle
+		{
+			reprap.GetPlatform().Message(GenericMessage, "Auto tune cancelled because starting temperature is not stable\n");
+			StopTuning();
+		}
 		break;
 
 	case TuningState::heatingUp:
-		//TODO
+		{
+			const bool isBedOrChamberHeater = reprap.GetHeat().IsBedOrChamberHeater(GetHeaterNumber());
+			const uint32_t heatingTime = now - timeSetHeating;
+			const float extraTimeAllowed = (isBedOrChamberHeater) ? 120.0 : 30.0;
+			if (heatingTime > (uint32_t)((GetModel().GetDeadTime() + extraTimeAllowed) * SecondsToMillis) && (lastTemperature - tuningStartTemp.GetMean()) < 3.0)
+			{
+				reprap.GetPlatform().Message(GenericMessage, "Auto tune cancelled because temperature is not increasing\n");
+				StopTuning();
+				break;
+			}
+
+			const uint32_t timeoutMinutes = (isBedOrChamberHeater) ? 30 : 7;
+			if (heatingTime >= timeoutMinutes * 60 * (uint32_t)SecondsToMillis)
+			{
+				reprap.GetPlatform().Message(GenericMessage, "Auto tune cancelled because target temperature was not reached\n");
+				StopTuning();
+				break;
+			}
+
+			if (lastTemperature >= tuningTargetTemp)							// if reached target
+			{
+				// Move on to next phase
+				peakTemp = afterPeakTemp = lastTemperature;
+				lastOffTime = peakTime = afterPeakTime = now;
+				tuningVoltage.Clear();
+				idleCyclesDone = 0;
+				newTuningResult = false;
+				tuningState = TuningState::idleCycles;
+				tuningPhase = 2;
+				reprap.GetPlatform().Message(GenericMessage, "Auto tune starting phase 2, heater settling\n");
+			}
+		}
 		break;
 
-	case TuningState::cyclingFanOff:
-		//TODO
+	case TuningState::idleCycles:
+		if (newTuningResult)
+		{
+			// To allow for heat reservoirs, we do idle cycles until the cooling rate decreases by no more than a certain amount in a single cycle
+			if (idleCyclesDone == TuningHeaterMaxIdleCycles || (idleCyclesDone >= TuningHeaterMinIdleCycles && currentCoolingRate >= lastCoolingRate * HeaterSettledCoolingTimeRatio))
+			{
+				tuningPhase = 3;
+				tuningState = TuningState::cyclingFanOff;
+				reprap.GetPlatform().Message(GenericMessage, "Auto tune starting phase 3, fan off\n");
+			}
+			else
+			{
+				lastCoolingRate = currentCoolingRate;
+				ClearCounters();
+				++idleCyclesDone;
+			}
+			newTuningResult = false;
+		}
 		break;
 
+	case TuningState::cyclingFanOff:
+#if TUNE_WITH_HALF_FAN
+	case TuningState::cyclingHalfFan:
+#endif
 	case TuningState::cyclingFanOn:
-		//TODO
+		if (newTuningResult)
+		{
+			if (coolingRate.GetNumSamples() >= MinTuningHeaterCycles)
+			{
+				const bool isConsistent = dLow.DeviationFractionWithin(0.2)
+										&& dHigh.DeviationFractionWithin(0.2)
+										&& heatingRate.DeviationFractionWithin(0.1)
+										&& coolingRate.DeviationFractionWithin(0.1);
+				if (isConsistent || coolingRate.GetNumSamples() == MaxTuningHeaterCycles)
+				{
+					if (!isConsistent)
+					{
+						reprap.GetPlatform().Message(WarningMessage, "heater behaviour was not consistent during tuning\n");
+					}
+
+					if (tuningState == TuningState::cyclingFanOff)
+					{
+						CalculateModel(fanOffParams);
+						if (tuningFans.IsEmpty())
+						{
+							SetAndReportModel(false);
+							break;
+						}
+						else
+						{
+							tuningPhase = 4;
+							ClearCounters();
+#if TUNE_WITH_HALF_FAN
+							tuningState = TuningState::cyclingFanHalf;
+							reprap.GetFansManager().SetFansValue(tuningFans, 0.5);		// turn fans on at half PWM
+							reprap.GetPlatform().Message(GenericMessage, "Auto tune starting phase 3, fan 50%\n");
+#else
+							tuningState = TuningState::cyclingFanOn;
+							reprap.GetFansManager().SetFansValue(tuningFans, 1.0);		// turn fans on at full PWM
+							reprap.GetPlatform().Message(GenericMessage, "Auto tune starting phase 3, fan on\n");
+#endif
+						}
+					}
+#if TUNE_WITH_HALF_FAN
+					else if (tuningState == TuningState::cyclingFanHalf)
+					{
+						CalculateModel(fanOnParams);
+						tuningPhase = 5;
+						tuningState = TuningState::cyclingFanOn;
+						ClearCounters();
+						reprap.GetFansManager().SetFansValue(tuningFans, 1.0);			// turn fans fully on
+						reprap.GetPlatform().Message(GenericMessage, "Auto tune starting phase 4, fan 100%\n");
+					}
+#endif
+					else
+					{
+						reprap.GetFansManager().SetFansValue(tuningFans, 0.0);			// turn fans off
+						CalculateModel(fanOnParams);
+						SetAndReportModel(true);
+						break;
+					}
+				}
+			}
+			newTuningResult = false;
+		}
 		break;
 	}
 }
@@ -98,10 +232,11 @@ GCodeResult RemoteHeater::ReportDetails(const StringRef& reply) const noexcept
 
 void RemoteHeater::SwitchOff() noexcept
 {
+	constexpr const char *errMsg = "Failed to switch off remote heater %u: %s\n";
 	CanMessageBuffer * const buf = CanMessageBuffer::Allocate();
 	if (buf == nullptr)
 	{
-		reprap.GetPlatform().MessageF(ErrorMessage, "Failed to switch off remote heater %u: no CAN buffer available\n", GetHeaterNumber());
+		reprap.GetPlatform().MessageF(ErrorMessage, errMsg, GetHeaterNumber(), "no CAN buffer available");
 	}
 	else
 	{
@@ -113,7 +248,7 @@ void RemoteHeater::SwitchOff() noexcept
 		String<StringLength100> reply;
 		if (CanInterface::SendRequestAndGetStandardReply(buf, rid, reply.GetRef()) != GCodeResult::ok)
 		{
-			reprap.GetPlatform().MessageF(ErrorMessage, "Failed to switch off remote heater %u: %s\n", GetHeaterNumber(), reply.c_str());
+			reprap.GetPlatform().MessageF(ErrorMessage, errMsg, GetHeaterNumber(), reply.c_str());
 		}
 	}
 }
@@ -173,8 +308,7 @@ GCodeResult RemoteHeater::StartAutoTune(const StringRef& reply, FansBitmap fans,
 	tuningTargetTemp = targetTemp;
 	tuningStartTemp.Clear();
 	tuningBeginTime = millis();
-	tuningPhase = 0;
-	tuned = false;					// assume failure
+	tuned = false;
 
 	if (seenA)
 	{
@@ -187,23 +321,38 @@ GCodeResult RemoteHeater::StartAutoTune(const StringRef& reply, FansBitmap fans,
 			return rslt;
 		}
 		tuningState = TuningState::heatingUp;
+		tuningPhase = 1;
 	}
 	else
 	{
 		tuningState = TuningState::stabilising;
+		tuningPhase = 0;
 	}
 
 	return GCodeResult::ok;
 }
 
-void RemoteHeater::GetAutoTuneStatus(const StringRef& reply) const noexcept
-{
-	reply.copy("remote heater auto tune not implemented");
-}
-
-void RemoteHeater::PrintCoolingFanPwmChanged(float pwmChange) noexcept
+void RemoteHeater::FeedForwardAdjustment(float fanPwmChange, float extrusionChange) noexcept
 {
-	//TODO send a CAN message to remote
+	constexpr const char* warnMsg = "Failed to make heater feedforward adjustment: %s\n";
+	CanMessageBuffer * const buf = CanMessageBuffer::Allocate();
+	if (buf == nullptr)
+	{
+		reprap.GetPlatform().MessageF(WarningMessage, warnMsg, "no CAN buffer");
+	}
+	else
+	{
+		const CanRequestId rid = CanInterface::AllocateRequestId(boardAddress);
+		auto msg = buf->SetupRequestMessage<CanMessageHeaterFeedForward>(rid, CanInterface::GetCanAddress(), boardAddress);
+		msg->heaterNumber = GetHeaterNumber();
+		msg->fanPwmAdjustment = fanPwmChange;
+		msg->extrusionAdjustment = extrusionChange;
+		String<StringLength100> reply;
+		if (CanInterface::SendRequestAndGetStandardReply(buf, rid, reply.GetRef()) != GCodeResult::ok)
+		{
+			reprap.GetPlatform().MessageF(WarningMessage, reply.c_str());
+		}
+	}
 }
 
 void RemoteHeater::Suspend(bool sus) noexcept
@@ -311,6 +460,23 @@ void RemoteHeater::UpdateRemoteStatus(CanAddress src, const CanHeaterReport& rep
 	}
 }
 
+void RemoteHeater::UpdateHeaterTuning(CanAddress src, const CanMessageHeaterTuningReport& msg) noexcept
+{
+	if (src == boardAddress && tuningState >= TuningState::idleCycles && !newTuningResult)
+	{
+		tOn.Add((float)msg.ton);
+		tOff.Add((float)msg.toff);
+		dHigh.Add((float)msg.dhigh);
+		dLow.Add((float)msg.dlow);
+		heatingRate.Add(msg.heatingRate);
+		coolingRate.Add(msg.coolingRate);
+		tuningVoltage.Add(msg.voltage);
+		currentCoolingRate = msg.coolingRate;
+		tuningCyclesDone = msg.cyclesDone;
+		newTuningResult = true;
+	}
+}
+
 GCodeResult RemoteHeater::SendTuningCommand(const StringRef& reply, bool on) noexcept
 {
 	CanMessageBuffer * const buf = CanMessageBuffer::Allocate();
@@ -331,6 +497,17 @@ GCodeResult RemoteHeater::SendTuningCommand(const StringRef& reply, bool on) noe
 	return CanInterface::SendRequestAndGetStandardReply(buf, rid, reply);
 }
 
+void RemoteHeater::StopTuning() noexcept
+{
+	tuningState = TuningState::notTuning;
+	String<StringLength100> reply;
+	if (SendTuningCommand(reply.GetRef(), false) != GCodeResult::ok)
+	{
+		reprap.GetPlatform().MessageF(ErrorMessage, "%s\n", reply.c_str());
+		reprap.GetPlatform().MessageF(ErrorMessage, "DANGER! Failed to stop tuning heater %u on CAN board %u, suggest turn power off\n", GetHeaterNumber(), boardAddress);
+	}
+}
+
 #endif
 
 // End
diff --git a/src/Heating/RemoteHeater.h b/src/Heating/RemoteHeater.h
index d39558d6..3ff8e066 100644
--- a/src/Heating/RemoteHeater.h
+++ b/src/Heating/RemoteHeater.h
@@ -28,10 +28,10 @@ public:
 	float GetTemperature() const noexcept override;							// Get the latest temperature
 	float GetAveragePWM() const noexcept override;							// Return the running average PWM to the heater. Answer is a fraction in [0, 1].
 	float GetAccumulator() const noexcept override;							// Return the integral accumulator
-	void GetAutoTuneStatus(const StringRef& reply) const noexcept override;	// Get the auto tune status or last result
 	void Suspend(bool sus) noexcept override;								// Suspend the heater to conserve power or while doing Z probing
-	void PrintCoolingFanPwmChanged(float pwmChange) noexcept override;
+	void FeedForwardAdjustment(float fanPwmChange, float extrusionChange) noexcept override;
 	void UpdateRemoteStatus(CanAddress src, const CanHeaterReport& report) noexcept override;
+	void UpdateHeaterTuning(CanAddress src, const CanMessageHeaterTuningReport& msg) noexcept override;
 
 protected:
 	void ResetHeater() noexcept override;
@@ -48,11 +48,16 @@ private:
 		notTuning = 0,
 		stabilising,
 		heatingUp,
+		idleCycles,
 		cyclingFanOff,
+#if TUNE_WITH_HALF_FAN
+		cyclingHalfFan,
+#endif
 		cyclingFanOn
 	};
 
 	GCodeResult SendTuningCommand(const StringRef& reply, bool on) noexcept;
+	void StopTuning() noexcept;
 
 	static constexpr uint32_t RemoteStatusTimeout = 2000;
 
@@ -62,7 +67,12 @@ private:
 	TuningState tuningState;
 	float lastTemperature;
 	uint32_t whenLastStatusReceived;
-	uint32_t timeSetHeating;												// When we turned on the heater at the start of auto tuning
+
+	// Variables used only during tuning
+	static uint32_t timeSetHeating;											// When we turned on the heater at the start of auto tuning
+	static float currentCoolingRate;
+	static unsigned int tuningCyclesDone;
+	static bool newTuningResult;
 };
 
 #endif
diff --git a/src/Tools/Tool.cpp b/src/Tools/Tool.cpp
index 5f346381..460d0506 100644
--- a/src/Tools/Tool.cpp
+++ b/src/Tools/Tool.cpp
@@ -622,7 +622,7 @@ void Tool::SetFansPwm(float f) const noexcept
 	const float pwmChange = reprap.GetFansManager().SetFansValue(fanMapping, f);
 	if (pwmChange != 0.0)
 	{
-		IterateHeaters([pwmChange](unsigned int heater) { reprap.GetHeat().PrintCoolingFanPwmChanged(heater, pwmChange); });
+		IterateHeaters([pwmChange](unsigned int heater) { reprap.GetHeat().FeedForwardAdjustment(heater, pwmChange, 0.0); });
 	}
 }