Version 1.16 release

Added I parameter in M280 command
Added diagnostic test (M122 S101) for SX1509B chip on Duet WiFi
expansion boards
Heaters driven from TC channels on Duet WiFi no longer glitch on for a
short while after reset
Bug fix: M280 S-1 was ignoring inverted output status
Bug fix: if there were too many files in the /gcodes folder then AJAX
errors occurred (thanks chrishamm)

11 files changed, 77 insertions, 58 deletions

diff --git a/src/Configuration.h b/src/Configuration.h
index 9d809ed4..42e01f49 100644
--- a/src/Configuration.h
+++ b/src/Configuration.h
@@ -26,11 +26,11 @@ Licence: GPL
 // Firmware name is now defined in the Pins file
 
 #ifndef VERSION
-# define VERSION "1.16rc3"
+# define VERSION "1.16"
 #endif
 
 #ifndef DATE
-# define DATE "2016-11-06"
+# define DATE "2016-11-08"
 #endif
 
 #define AUTHORS "reprappro, dc42, zpl, t3p3, dnewman"
@@ -155,11 +155,14 @@ const size_t FILENAME_LENGTH = 100;
 #ifdef DUET_NG
 const uint16_t OUTPUT_BUFFER_SIZE = 256;			// How many bytes does each OutputBuffer hold?
 const size_t OUTPUT_BUFFER_COUNT = 32;				// How many OutputBuffer instances do we have?
+const size_t RESERVED_OUTPUT_BUFFERS = 1;			// Number of reserved output buffers after long responses. Must be enough for an HTTP header
 #else
 const uint16_t OUTPUT_BUFFER_SIZE = 128;			// How many bytes does each OutputBuffer hold?
 const size_t OUTPUT_BUFFER_COUNT = 32;				// How many OutputBuffer instances do we have?
+const size_t RESERVED_OUTPUT_BUFFERS = 2;			// Number of reserved output buffers after long responses. Must be enough for an HTTP header
 #endif
 
+
 // Move system
 
 const float DEFAULT_FEEDRATE = 3000.0;				// The initial requested feed rate after resetting the printer
diff --git a/src/DuetNG/DueXn.cpp b/src/DuetNG/DueXn.cpp
index ac6f0785..c89d50b0 100644
--- a/src/DuetNG/DueXn.cpp
+++ b/src/DuetNG/DueXn.cpp
@@ -72,8 +72,7 @@ namespace DuetExpansion
 
 			expander.pinModeMultiple(AllFanBits, OUTPUT_PWM);			// Initialise the PWM pins
 			const uint16_t stopBits = (boardType == ExpansionBoardType::DueX5) ? AllStopBitsX5 : AllStopBitsX2;	// I am assuming that the X0 has 2 endstop inputs
-			expander.pinModeMultiple(stopBits, INPUT);					// Initialise the endstop inputs (no pullups because 5V-tolerant)
-			expander.pinModeMultiple(AllGpioBits, INPUT);				// Initialise the GPIO pins as inputs
+			expander.pinModeMultiple(stopBits | AllGpioBits, INPUT);	// Initialise the endstop inputs and GPIO pins (no pullups because 5V-tolerant)
 
 			// Set up the interrupt on any input change
 			inputMask = stopBits | AllGpioBits;
@@ -170,6 +169,16 @@ namespace DuetExpansion
 			expander.analogWrite(pin, (uint8_t)(constrain<float>(pwm, 0.0, 1.0) * 255));
 		}
 	}
+
+	// Diagnose the SX1509 by setting all pins as inputs and reading them
+	uint16_t DiagnosticRead()
+	{
+		expander.pinModeMultiple(AllStopBitsX5 | AllGpioBits | AllFanBits, INPUT);	// Initialise the endstop inputs and GPIO pins (no pullups because 5V-tolerant)
+		delay(1);
+		const uint16_t retval = expander.digitalReadAll();	// read all inputs with pullup resistors on fans
+		Init();															// back to normal
+		return retval;
+	}
 }			// end namespace
 
 // End
diff --git a/src/DuetNG/DueXn.h b/src/DuetNG/DueXn.h
index 312620ec..e943b116 100644
--- a/src/DuetNG/DueXn.h
+++ b/src/DuetNG/DueXn.h
@@ -27,6 +27,7 @@ namespace DuetExpansion
 	bool DigitalRead(Pin pin);						// Read a pin
 	void DigitalWrite(Pin pin, bool high);			// Write a pin
 	void AnalogOut(Pin pin, float pwm);				// Set the PWM value on this pin
+	uint16_t DiagnosticRead();						// Diagnose the SX1509 by setting all pins as inputs and reading them
 };
 
 #endif /* SRC_DUETNG_DUEXN_H_ */
diff --git a/src/DuetNG/SX1509.cpp b/src/DuetNG/SX1509.cpp
index 7837a1d5..98035cca 100644
--- a/src/DuetNG/SX1509.cpp
+++ b/src/DuetNG/SX1509.cpp
@@ -87,24 +87,31 @@ void SX1509::pinModeMultiple(uint16_t pins, PinMode inOut)
 	switch (inOut)
 	{
 	case INPUT:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
+		clearBitsInWord(REG_INPUT_DISABLE_B, pins);
 		setBitsInWord(REG_DIR_B, pins);
 		clearBitsInWord(REG_PULL_UP_B, pins);
 		clearBitsInWord(REG_PULL_DOWN_B, pins);
 		break;
 
 	case INPUT_PULLUP:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
+		clearBitsInWord(REG_INPUT_DISABLE_B, pins);
 		setBitsInWord(REG_DIR_B, pins);
-		setBitsInWord(REG_PULL_UP_B, pins);
 		clearBitsInWord(REG_PULL_DOWN_B, pins);
+		setBitsInWord(REG_PULL_UP_B, pins);
 		break;
 
 	case INPUT_PULLDOWN:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
+		clearBitsInWord(REG_INPUT_DISABLE_B, pins);
 		setBitsInWord(REG_DIR_B, pins);
 		clearBitsInWord(REG_PULL_UP_B, pins);
 		setBitsInWord(REG_PULL_DOWN_B, pins);
 		break;
 
 	case OUTPUT_LOW:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
 		clearBitsInWord(REG_PULL_UP_B, pins);
 		clearBitsInWord(REG_PULL_DOWN_B, pins);
 		clearBitsInWord(REG_DATA_B, pins);
@@ -113,6 +120,7 @@ void SX1509::pinModeMultiple(uint16_t pins, PinMode inOut)
 		break;
 
 	case OUTPUT_HIGH:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
 		clearBitsInWord(REG_PULL_UP_B, pins);
 		clearBitsInWord(REG_PULL_DOWN_B, pins);
 		setBitsInWord(REG_DATA_B, pins);
@@ -121,6 +129,7 @@ void SX1509::pinModeMultiple(uint16_t pins, PinMode inOut)
 		break;
 
 	case OUTPUT_LOW_OPEN_DRAIN:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
 		clearBitsInWord(REG_PULL_UP_B, pins);
 		clearBitsInWord(REG_PULL_DOWN_B, pins);
 		clearBitsInWord(REG_DATA_B, pins);
@@ -129,6 +138,7 @@ void SX1509::pinModeMultiple(uint16_t pins, PinMode inOut)
 		break;
 
 	case OUTPUT_HIGH_OPEN_DRAIN:
+		clearBitsInWord(REG_LED_DRIVER_ENABLE_B, pins);
 		clearBitsInWord(REG_PULL_UP_B, pins);
 		clearBitsInWord(REG_PULL_DOWN_B, pins);
 		setBitsInWord(REG_DATA_B, pins);
diff --git a/src/GCodes/GCodes.cpp b/src/GCodes/GCodes.cpp
index c65b0d01..771daa2d 100644
--- a/src/GCodes/GCodes.cpp
+++ b/src/GCodes/GCodes.cpp
@@ -4181,13 +4181,20 @@ bool GCodes::HandleMcode(GCodeBuffer* gb, StringRef& reply)
 			bool invert;
 			if (platform->GetFirmwarePin(servoIndex, PinAccess::servo, servoPin, invert))
 			{
+				if (gb->Seen('I'))
+				{
+					if (gb->GetIValue() > 0)
+					{
+						invert = !invert;
+					}
+				}
 				if (gb->Seen('S'))
 				{
 					float angleOrWidth = gb->GetFValue();
 					if (angleOrWidth < 0.0)
 					{
 						// Disable the servo by setting the pulse width to zero
-						Platform::WriteAnalog(servoPin, 0.0, ServoRefreshFrequency);
+						Platform::WriteAnalog(servoPin, (invert) ? 1.0 : 0.0, ServoRefreshFrequency);
 					}
 					else
 					{
diff --git a/src/Heating/Pid.cpp b/src/Heating/Pid.cpp
index e1a8190c..836d009f 100644
--- a/src/Heating/Pid.cpp
+++ b/src/Heating/Pid.cpp
@@ -786,7 +786,7 @@ void PID::FitCurve()
 void PID::DisplayBuffer(const char *intro)
 {
 	OutputBuffer *buf;
-	if (OutputBuffer::Allocate(buf, false))
+	if (OutputBuffer::Allocate(buf))
 	{
 		buf->catf("%s: interval %.1f sec, readings", intro, tuningReadingInterval * MillisToSeconds);
 		for (size_t i = 0; i < tuningReadingsTaken; ++i)
diff --git a/src/OutputMemory.cpp b/src/OutputMemory.cpp
index 3e187814..b907cfa3 100644
--- a/src/OutputMemory.cpp
+++ b/src/OutputMemory.cpp
@@ -86,37 +86,34 @@ const char *OutputBuffer::Read(size_t len)
 	return data + offset;
 }
 
-int OutputBuffer::printf(const char *fmt, ...)
+size_t OutputBuffer::printf(const char *fmt, ...)
 {
 	char formatBuffer[FORMAT_STRING_LENGTH];
 	va_list vargs;
 	va_start(vargs, fmt);
-	int ret = vsnprintf(formatBuffer, ARRAY_SIZE(formatBuffer), fmt, vargs);
+	vsnprintf(formatBuffer, ARRAY_SIZE(formatBuffer), fmt, vargs);
 	va_end(vargs);
 
-	copy(formatBuffer);
-	return ret;
+	return copy(formatBuffer);
 }
 
-int OutputBuffer::vprintf(const char *fmt, va_list vargs)
+size_t OutputBuffer::vprintf(const char *fmt, va_list vargs)
 {
 	char formatBuffer[FORMAT_STRING_LENGTH];
-	int res = vsnprintf(formatBuffer, ARRAY_SIZE(formatBuffer), fmt, vargs);
+	vsnprintf(formatBuffer, ARRAY_SIZE(formatBuffer), fmt, vargs);
 
-	cat(formatBuffer);
-	return res;
+	return cat(formatBuffer);
 }
 
-int OutputBuffer::catf(const char *fmt, ...)
+size_t OutputBuffer::catf(const char *fmt, ...)
 {
 	char formatBuffer[FORMAT_STRING_LENGTH];
 	va_list vargs;
 	va_start(vargs, fmt);
-	int ret = vsnprintf(formatBuffer, ARRAY_SIZE(formatBuffer), fmt, vargs);
+	vsnprintf(formatBuffer, ARRAY_SIZE(formatBuffer), fmt, vargs);
 	va_end(vargs);
 
-	cat(formatBuffer);
-	return ret;
+	return cat(formatBuffer);
 }
 
 size_t OutputBuffer::copy(const char c)
@@ -157,7 +154,7 @@ size_t OutputBuffer::copy(const char *src, size_t len)
 		OutputBuffer *currentBuffer;
 		size_t bytesCopied = OUTPUT_BUFFER_SIZE;
 		do {
-			if (!Allocate(currentBuffer, true))
+			if (!Allocate(currentBuffer))
 			{
 				// We cannot store the whole string, stop here
 				break;
@@ -207,7 +204,7 @@ size_t OutputBuffer::cat(const char c)
 	{
 		// No - allocate a new item and copy the data
 		OutputBuffer *nextBuffer;
-		if (!Allocate(nextBuffer, true))
+		if (!Allocate(nextBuffer))
 		{
 			// We cannot store any more data. Should never happen
 			return 0;
@@ -247,7 +244,7 @@ size_t OutputBuffer::cat(const char *src, size_t len)
 	{
 		// Yes - copy what we couldn't write into a new chain
 		OutputBuffer *nextBuffer;
-		if (!Allocate(nextBuffer, true))
+		if (!Allocate(nextBuffer))
 		{
 			// We cannot store any more data, stop here
 			return copyLength;
@@ -360,7 +357,7 @@ size_t OutputBuffer::EncodeReply(OutputBuffer *src, bool allowControlChars)
 }
 
 // Allocates an output buffer instance which can be used for (large) string outputs
-/*static*/ bool OutputBuffer::Allocate(OutputBuffer *&buf, bool isAppending)
+/*static*/ bool OutputBuffer::Allocate(OutputBuffer *&buf)
 {
 	const irqflags_t flags = cpu_irq_save();
 
@@ -372,18 +369,6 @@ size_t OutputBuffer::EncodeReply(OutputBuffer *src, bool allowControlChars)
 		buf = nullptr;
 		return false;
 	}
-	else if (isAppending)
-	{
-		// It's a good idea to leave at least one OutputBuffer available if we're
-		// writing a large chunk of data...
-		if (freeOutputBuffers->next == nullptr)
-		{
-			cpu_irq_restore(flags);
-
-			buf = nullptr;
-			return false;
-		}
-	}
 
 	buf = freeOutputBuffers;
 	freeOutputBuffers = buf->next;
@@ -407,32 +392,28 @@ size_t OutputBuffer::EncodeReply(OutputBuffer *src, bool allowControlChars)
 // Get the number of bytes left for continuous writing
 /*static*/ size_t OutputBuffer::GetBytesLeft(const OutputBuffer *writingBuffer)
 {
-	// If writingBuffer is NULL, just return how much space there is left for continuous writing
+	size_t freeOutputBuffers = OUTPUT_BUFFER_COUNT - usedOutputBuffers;
 	if (writingBuffer == nullptr)
 	{
-		if (usedOutputBuffers == OUTPUT_BUFFER_COUNT)
-		{
-			// No more instances can be allocated
-			return 0;
-		}
-
-		return (OUTPUT_BUFFER_COUNT - usedOutputBuffers - 1) * OUTPUT_BUFFER_SIZE;
+		// Only return the total number of bytes left
+		return freeOutputBuffers * OUTPUT_BUFFER_SIZE;
 	}
 
-	// Do we have any more buffers left for writing?
-	if (usedOutputBuffers == OUTPUT_BUFFER_COUNT)
+	// We're doing a possibly long response like a filelist
+	size_t bytesLeft = OUTPUT_BUFFER_SIZE - writingBuffer->last->DataLength();
+
+	if (freeOutputBuffers < RESERVED_OUTPUT_BUFFERS)
 	{
-		// No - refer to this one only
-		return OUTPUT_BUFFER_SIZE - writingBuffer->last->DataLength();
+		// Keep some space left to encapsulate the respones (e.g. via an HTTP header)
+		return bytesLeft;
 	}
 
-	// Yes - we know how many buffers are in use, so there is no need to work through the free list
-	return (OUTPUT_BUFFER_SIZE - writingBuffer->last->DataLength() + (OUTPUT_BUFFER_COUNT - usedOutputBuffers - 1) * OUTPUT_BUFFER_SIZE);
+	return bytesLeft + (freeOutputBuffers - RESERVED_OUTPUT_BUFFERS) * OUTPUT_BUFFER_SIZE;
 }
 
 
 // Truncate an output buffer to free up more memory. Returns the number of released bytes.
-/*static */ size_t OutputBuffer::Truncate(OutputBuffer *buffer, size_t bytesNeeded )
+/*static */ size_t OutputBuffer::Truncate(OutputBuffer *buffer, size_t bytesNeeded)
 {
 	// Can we free up space from this chain? Don't break it up if it's referenced anywhere else
 	if (buffer == nullptr || buffer->Next() == nullptr || buffer->IsReferenced())
diff --git a/src/OutputMemory.h b/src/OutputMemory.h
index 8106f974..629fbe4f 100644
--- a/src/OutputMemory.h
+++ b/src/OutputMemory.h
@@ -39,9 +39,9 @@ class OutputBuffer
 		const char *Read(size_t len);
 		size_t BytesLeft() const { return dataLength - bytesRead; }	// How many bytes have not been sent yet?
 
-		int printf(const char *fmt, ...);
-		int vprintf(const char *fmt, va_list vargs);
-		int catf(const char *fmt, ...);
+		size_t printf(const char *fmt, ...);
+		size_t vprintf(const char *fmt, va_list vargs);
+		size_t catf(const char *fmt, ...);
 
 		size_t copy(const char c);
 		size_t copy(const char *src);
@@ -61,8 +61,7 @@ class OutputBuffer
 		static void Init();
 
 		// Allocate an unused OutputBuffer instance. Returns true on success or false if no instance could be allocated.
-		// Setting isAppending to true will guarantee that one OutputBuffer will remain available for single allocation.
-		static bool Allocate(OutputBuffer *&buf, bool isAppending = false);
+		static bool Allocate(OutputBuffer *&buf);
 
 		// Get the number of bytes left for allocation. If writingBuffer is not NULL, this returns the number of free bytes for
 		// continuous writes, i.e. for writes that need to allocate an extra OutputBuffer instance to finish the message.
diff --git a/src/Platform.cpp b/src/Platform.cpp
index bbbf0573..20409663 100644
--- a/src/Platform.cpp
+++ b/src/Platform.cpp
@@ -1507,6 +1507,12 @@ void Platform::DiagnosticTest(int d)
 		DDA::PrintMoves();
 		break;
 
+#ifdef DUET_NG
+	case (int)DiagnosticTestType::PrintExpanderStatus:
+		MessageF(GENERIC_MESSAGE, "Expander status %04X\n", DuetExpansion::DiagnosticRead());
+		break;
+#endif
+
 	default:
 		break;
 	}
diff --git a/src/Platform.h b/src/Platform.h
index e5ce5480..94ea54bc 100644
--- a/src/Platform.h
+++ b/src/Platform.h
@@ -236,7 +236,10 @@ enum class DiagnosticTestType : int
 	TestWatchdog = 1001,			// test that we get a watchdog reset if the tick interrupt stops
 	TestSpinLockup = 1002,			// test that we get a software reset if a Spin() function takes too long
 	TestSerialBlock = 1003,			// test what happens when we write a blocking message via debugPrintf()
-	PrintMoves = 100				// print summary of recent moves
+	PrintMoves = 100,				// print summary of recent moves
+#ifdef DUET_NG
+	PrintExpanderStatus = 101,		// print DueXn expander status
+#endif
 };
 
 // Enumeration to describe what we want to do with a logical pin
diff --git a/src/Reprap.cpp b/src/Reprap.cpp
index a0a9300e..6b39b3ff 100644
--- a/src/Reprap.cpp
+++ b/src/Reprap.cpp
@@ -896,14 +896,14 @@ OutputBuffer *RepRap::GetStatusResponse(uint8_t type, ResponseSource source)
 
 	if (source == ResponseSource::AUX)
 	{
-		OutputBuffer *response = platform->GetAuxGCodeReply();
+		OutputBuffer *reply = platform->GetAuxGCodeReply();
 		if (response != nullptr)
 		{
 			// Send the response to the last command. Do this last
 			response->catf(",\"seq\":%u,\"resp\":", platform->GetAuxSeq());			// send the response sequence number
 
 			// Send the JSON response
-			response->EncodeReply(response, true);									// also releases the OutputBuffer chain
+			response->EncodeReply(reply, true);										// also releases the OutputBuffer chain
 		}
 	}
 	response->cat("}");