Support longer step pulses on MB6XD when in test mode

3 files changed, 34 insertions, 20 deletions

diff --git a/src/CAN/CanInterface.cpp b/src/CAN/CanInterface.cpp
index b7827e4d..94aabd0c 100644
--- a/src/CAN/CanInterface.cpp
+++ b/src/CAN/CanInterface.cpp
@@ -332,6 +332,9 @@ void CanInterface::SwitchToExpansionMode(CanAddress addr, bool useTestMode) noex
 	inExpansionMode = true;
 	inTestMode = useTestMode;
 	reprap.GetGCodes().SwitchToExpansionMode();
+#ifdef DUET3_MB6XD
+	reprap.GetPlatform().InitStepGateTimer();		// change the step gate timer to allow longer pulses for ATE
+#endif
 	ReInit();										// reset the CAN filters to account for our new CAN address
 }
 
diff --git a/src/Platform/Platform.cpp b/src/Platform/Platform.cpp
index e9dfb10f..82bb839c 100644
--- a/src/Platform/Platform.cpp
+++ b/src/Platform/Platform.cpp
@@ -647,19 +647,7 @@ void Platform::Init() noexcept
 
 #ifdef DUET3_MB6XD
 	driverErrPinsActiveLow = (numErrorHighDrivers >= NumDirectDrivers/2);				// determine the error signal polarity by assuming most drivers are not in the error state
-
-	// Set up the step gate timer
-	pmc_enable_periph_clk(STEP_GATE_TC_ID);
-	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_CCR = TC_CCR_CLKDIS;
-	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_CMR =  TC_CMR_BSWTRG_SET				// software trigger sets TIOB
-														| TC_CMR_BCPC_CLEAR				// RC compare clears TIOB
-														| TC_CMR_WAVE					// waveform mode
-														| TC_CMR_WAVSEL_UP				// count up
-														| TC_CMR_CPCSTOP				// counter clock is stopped when counter reaches RC
-														| TC_CMR_EEVT_XC0   			// set external events from XC0 (this allows TIOB to be an output)
-														| TC_CMR_TCCLKS_TIMER_CLOCK2;	// divide MCLK (150MHz) by 8 = 18.75MHz
-	SetPinFunction(StepGatePin, StepGatePinFunction);
-	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_CCR = TC_CCR_CLKEN;
+	InitStepGateTimer();
 #endif
 
 	// Set up the axis+extruder arrays
@@ -705,9 +693,7 @@ void Platform::Init() noexcept
 #endif
 	}
 
-#ifdef DUET3_MB6XD
-	UpdateDriverTimings();
-#else
+#ifndef DUET3_MB6XD
 	for (uint32_t& entry : slowDriverStepTimingClocks)
 	{
 		entry = 0;												// reset all to zero as we have no known slow drivers yet
@@ -2763,6 +2749,27 @@ GCodeResult Platform::SetMotorCurrent(size_t axisOrExtruder, float currentOrPerc
 
 #ifdef DUET3_MB6XD
 
+// Set up the step gate timer. We reduce the speed to allow longer pulses when in test mode.
+void Platform::InitStepGateTimer() noexcept
+{
+	pmc_enable_periph_clk(STEP_GATE_TC_ID);
+	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_CCR = TC_CCR_CLKDIS;
+	const uint32_t clockDiv = (CanInterface::InTestMode())
+								? TC_CMR_TCCLKS_TIMER_CLOCK3							// divide MCLK (150MHz) by 32 = 4.6875MHz
+									: TC_CMR_TCCLKS_TIMER_CLOCK2;						// divide MCLK (150MHz) by 8 = 18.75MHz
+	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_CMR =  TC_CMR_BSWTRG_SET				// software trigger sets TIOB
+														| TC_CMR_BCPC_CLEAR				// RC compare clears TIOB
+														| TC_CMR_WAVE					// waveform mode
+														| TC_CMR_WAVSEL_UP				// count up
+														| TC_CMR_CPCSTOP				// counter clock is stopped when counter reaches RC
+														| TC_CMR_EEVT_XC0   			// set external events from XC0 (this allows TIOB to be an output)
+														| clockDiv;						// divide MCLK (150MHz) by 8 or 32
+	SetPinFunction(StepGatePin, StepGatePinFunction);
+	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_CCR = TC_CCR_CLKEN;
+
+	UpdateDriverTimings();
+}
+
 // Fetch the worst (longest) timings of any driver, set up the step pulse width timer, and convert the other timings from microseconds to step clocks
 void Platform::UpdateDriverTimings() noexcept
 {
@@ -2779,8 +2786,8 @@ void Platform::UpdateDriverTimings() noexcept
 	}
 
 	// Convert the step pulse width to clocks of the step pulse gate timer. First define some constants.
-	constexpr uint32_t StepGateTcClockFrequency = (SystemCoreClockFreq/2)/8;
-	constexpr float StepGateClocksPerMicrosecond = (float)StepGateTcClockFrequency/1.0e6;
+	const uint32_t StepGateTcClockFrequency = (CanInterface::InTestMode()) ? (SystemCoreClockFreq/2)/32 : (SystemCoreClockFreq/2)/8;
+	const float StepGateClocksPerMicrosecond = (float)StepGateTcClockFrequency/1.0e6;
 	const float fclocks = min<float>(ceilf(worstTimings[0] * StepGateClocksPerMicrosecond), 65535.0);		// the TC is only 16 bits wide
 	STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_RC = (uint32_t)fclocks;
 
@@ -2797,8 +2804,8 @@ void Platform::UpdateDriverTimings() noexcept
 
 void Platform::GetActualDriverTimings(float timings[4]) noexcept
 {
-	constexpr uint32_t StepGateTcClockFrequency = (SystemCoreClockFreq/2)/8;
-	constexpr float MicrosecondsPerStepGateClock = 1.0e6/(float)StepGateTcClockFrequency;
+	const uint32_t StepGateTcClockFrequency = (CanInterface::InTestMode()) ? (SystemCoreClockFreq/2)/32 : (SystemCoreClockFreq/2)/8;
+	const float MicrosecondsPerStepGateClock = 1.0e6/(float)StepGateTcClockFrequency;
 	constexpr float StepClocksToMicroseconds = 1.0e6/(float)StepClockRate;
 	timings[0] = (float)STEP_GATE_TC->TC_CHANNEL[STEP_GATE_TC_CHAN].TC_RC * MicrosecondsPerStepGateClock;
 	timings[1] = stepPulseMinimumPeriodClocks * StepClocksToMicroseconds - timings[0];
diff --git a/src/Platform/Platform.h b/src/Platform/Platform.h
index a8ae2c27..518a26ee 100644
--- a/src/Platform/Platform.h
+++ b/src/Platform/Platform.h
@@ -680,6 +680,10 @@ public:
 	void OnProcessingCanMessage() noexcept;								// called when we start processing any CAN message except for regular messages e.g. time sync
 #endif
 
+#ifdef DUET3_MB6XD
+	void InitStepGateTimer() noexcept;
+#endif
+
 protected:
 	DECLARE_OBJECT_MODEL
 	OBJECT_MODEL_ARRAY(axisDrivers)