/****************************************************************************************************

 RepRapFirmware - Platform: RepRapPro Ormerod with Arduino Due controller

 Platform contains all the code and definitions to deal with machine-dependent things such as control
 pins, bed area, number of extruders, tolerable accelerations and speeds and so on.

 -----------------------------------------------------------------------------------------------------

 Version 0.1

 18 November 2012

 Adrian Bowyer
 RepRap Professional Ltd
 http://reprappro.com

 Licence: GPL

 ****************************************************************************************************/

#include "RepRapFirmware.h"
#include "DueFlashStorage.h"
#include "lwip/src/include/lwip/stats.h"

extern char _end;
extern "C" char *sbrk(int i);

const uint8_t memPattern = 0xA5;

// Arduino initialise and loop functions
// Put nothing in these other than calls to the RepRap equivalents

void setup()
{
	// Fill the free memory with a pattern so that we can check for stack usage and memory corruption
	char* heapend = sbrk(0);
	register const char * stack_ptr asm ("sp");
	while (heapend + 16 < stack_ptr)
	{
		*heapend++ = memPattern;
	}

	reprap.Init();
}

void loop()
{
	reprap.Spin();
}

extern "C"
{
	// This intercepts the 1ms system tick. It must return 'false', otherwise the Arduino core tick handler will be bypassed.
	int sysTickHook()
	{
		reprap.Tick();
		return 0;
	}
}

//*************************************************************************************************
// PidParameters class

bool PidParameters::UsePID() const
{
	return kP >= 0;
}

float PidParameters::GetThermistorR25() const
{
	return thermistorInfR * exp(thermistorBeta / (25.0 - ABS_ZERO));
}

void PidParameters::SetThermistorR25AndBeta(float r25, float beta)
{
	thermistorInfR = r25 * exp(-beta / (25.0 - ABS_ZERO));
	thermistorBeta = beta;
}

bool PidParameters::operator==(const PidParameters& other) const
{
	return kI == other.kI && kD == other.kD && kP == other.kP && kT == other.kT && kS == other.kS
			&& fullBand == other.fullBand && pidMin == other.pidMin
			&& pidMax == other.pidMax && thermistorBeta == other.thermistorBeta && thermistorInfR == other.thermistorInfR
			&& thermistorSeriesR == other.thermistorSeriesR && adcLowOffset == other.adcLowOffset
			&& adcHighOffset == other.adcHighOffset;
}

//*************************************************************************************************
// Platform class

Platform::Platform() :
		tickState(0), fileStructureInitialised(false), active(false), errorCodeBits(0), debugCode(0)
{
	line = new Line();

	// Files

	massStorage = new MassStorage(this);

	for (int8_t i = 0; i < MAX_FILES; i++)
	{
		files[i] = new FileStore(this);
	}
}

//*******************************************************************************************************************

void Platform::Init()
{
	digitalWrite(atxPowerPin, LOW);		// ensure ATX power is off by default
	pinMode(atxPowerPin, OUTPUT);

	DueFlashStorage::init();
	// We really want to use static_assert here, but the ancient version of gcc used by Arduino doesn't support it
	//static_assert(sizeof(nvData) <= 1024, "NVData too large");
	// So instead, create a reference to a non-existent declaration if the condition fails.
	// We are relying on the compiler optimizing this out if the condition is false
	// Watch out for the build warning "undefined reference to 'NonExistantFunction()' if this fails.
	if (!(sizeof(nvData) <= 1024))
	{
		extern void BadStaticAssert();
		BadStaticAssert();
	}
	DueFlashStorage::read(nvAddress, &nvData, sizeof(nvData));
	if (nvData.magic != FlashData::magicValue)
	{
		// Nonvolatile data has not been initialized since the firmware was last written, so set up default values
		nvData.compatibility = me;
		nvData.ipAddress = IP_ADDRESS;
		nvData.netMask = NET_MASK;
		nvData.gateWay = GATE_WAY;
		nvData.macAddress = MAC_ADDRESS;

		nvData.zProbeType = 0;	// Default is to use the switch
		nvData.zProbeAxes = Z_PROBE_AXES;
		nvData.switchZProbeParameters.Init(0.0);
		nvData.irZProbeParameters.Init(Z_PROBE_STOP_HEIGHT);
		nvData.alternateZProbeParameters.Init(Z_PROBE_STOP_HEIGHT);

		for (size_t i = 0; i < HEATERS; ++i)
		{
			PidParameters& pp = nvData.pidParams[i];
			pp.thermistorSeriesR = defaultThermistorSeriesRs[i];
			pp.SetThermistorR25AndBeta(defaultThermistor25RS[i], defaultThermistorBetas[i]);
			pp.kI = defaultPidKis[i];
			pp.kD = defaultPidKds[i];
			pp.kP = defaultPidKps[i];
			pp.kT = defaultPidKts[i];
			pp.kS = defaultPidKss[i];
			pp.fullBand = defaultFullBand[i];
			pp.pidMin = defaultPidMin[i];
			pp.pidMax = defaultPidMax[i];
			pp.adcLowOffset = pp.adcHighOffset = 0.0;
		}

		nvData.resetReason = 0;
		GetStackUsage(NULL, NULL, &nvData.neverUsedRam);
		nvData.magic = FlashData::magicValue;
		WriteNvData();
	}

	line->Init();
	messageIndent = 0;

	massStorage->Init();

	for (size_t i = 0; i < MAX_FILES; i++)
	{
		files[i]->Init();
	}

	fileStructureInitialised = true;

	mcpDuet.begin(); //only call begin once in the entire execution, this begins the I2C comms on that channel for all objects
	mcpExpansion.setMCP4461Address(0x2E); //not required for mcpDuet, as this uses the default address
	sysDir = SYS_DIR;
	configFile = CONFIG_FILE;

	// DRIVES

	stepPins = STEP_PINS;
	directionPins = DIRECTION_PINS;
	enablePins = ENABLE_PINS;
	disableDrives = DISABLE_DRIVES;
	lowStopPins = LOW_STOP_PINS;
	highStopPins = HIGH_STOP_PINS;
	maxFeedrates = MAX_FEEDRATES;
	accelerations = ACCELERATIONS;
	driveStepsPerUnit = DRIVE_STEPS_PER_UNIT;
	instantDvs = INSTANT_DVS;
	potWipes = POT_WIPES;
	senseResistor = SENSE_RESISTOR;
	maxStepperDigipotVoltage = MAX_STEPPER_DIGIPOT_VOLTAGE;
	numMixingDrives = NUM_MIXING_DRIVES;

	// Z PROBE

	zProbePin = Z_PROBE_PIN;
	zProbeModulationPin = Z_PROBE_MOD_PIN;
	zProbeAdcChannel = PinToAdcChannel(zProbePin);
	InitZProbe();

	// AXES

	axisMaxima = AXIS_MAXIMA;
	axisMinima = AXIS_MINIMA;
	homeFeedrates = HOME_FEEDRATES;
	headOffsets = HEAD_OFFSETS;

	SetSlowestDrive();

	// HEATERS - Bed is assumed to be the first

	tempSensePins = TEMP_SENSE_PINS;
	heatOnPins = HEAT_ON_PINS;
	heatSampleTime = HEAT_SAMPLE_TIME;
	standbyTemperatures = STANDBY_TEMPERATURES;
	activeTemperatures = ACTIVE_TEMPERATURES;
	coolingFanPin = COOLING_FAN_PIN;

	webDir = WEB_DIR;
	gcodeDir = GCODE_DIR;
	tempDir = TEMP_DIR;

  /*
  	FIXME Nasty having to specify individually if a pin is arduino or not.
    requires a unified variant file. If implemented this would be much better
	to allow for different hardware in the future
  */
	for (size_t i = 0; i < DRIVES; i++)
	{
		if (stepPins[i] >= 0)
		{
		  if(i == E0_DRIVE || i == E3_DRIVE) // STEP_PINS {14, 25, 5, X2, 41, 39, X4, 49}
				pinModeNonDue(stepPins[i], OUTPUT);
			else
				pinMode(stepPins[i], OUTPUT);
		}
		if (directionPins[i] >= 0)
		{
		  if(i == E0_DRIVE) // DIRECTION_PINS {15, 26, 4, X3, 35, 53, 51, 48}
				pinModeNonDue(directionPins[i], OUTPUT);
			else
				pinMode(directionPins[i], OUTPUT);
		}
		if (enablePins[i] >= 0)
		{
		  if(i == Z_AXIS || i == E0_DRIVE || i == E2_DRIVE) // ENABLE_PINS {29, 27, X1, X0, 37, X8, 50, 47}
				pinModeNonDue(enablePins[i], OUTPUT);
			else
				pinMode(enablePins[i], OUTPUT);
		}
		Disable(i);
		driveEnabled[i] = false;
	}
	for(size_t i = 0; i < DRIVES; i++)
	{
		if (lowStopPins[i] >= 0)
		{
			pinMode(lowStopPins[i], INPUT);
			digitalWrite(lowStopPins[i], HIGH); // Turn on pullup
		}
		if (highStopPins[i] >= 0)
		{
			pinMode(highStopPins[i], INPUT);
			digitalWrite(highStopPins[i], HIGH); // Turn on pullup
		}
	}

	for (size_t i = 0; i < HEATERS; i++)
	{
		if (heatOnPins[i] >= 0)
		{
			if(i == E0_HEATER || i == E1_HEATER) // HEAT_ON_PINS {6, X5, X7, 7, 8, 9}
			{
				digitalWriteNonDue(heatOnPins[i], HIGH);	// turn the heater off
				pinModeNonDue(heatOnPins[i], OUTPUT);
			}
			else
			{
				digitalWrite(heatOnPins[i], HIGH);			// turn the heater off
				pinMode(heatOnPins[i], OUTPUT);
			}
		}
		analogReadResolution(12);
		thermistorFilters[i].Init(analogRead(tempSensePins[i]));
		heaterAdcChannels[i] = PinToAdcChannel(tempSensePins[i]);

		// Calculate and store the ADC average sum that corresponds to an overheat condition, so that we can check is quickly in the tick ISR
		float thermistorOverheatResistance = nvData.pidParams[i].GetRInf()
				* exp(-nvData.pidParams[i].GetBeta() / (BAD_HIGH_TEMPERATURE - ABS_ZERO));
		float thermistorOverheatAdcValue = (adRangeReal + 1) * thermistorOverheatResistance
				/ (thermistorOverheatResistance + nvData.pidParams[i].thermistorSeriesR);
		thermistorOverheatSums[i] = (uint32_t) (thermistorOverheatAdcValue + 0.9) * numThermistorReadingsAveraged;
	}

	if (coolingFanPin >= 0)
	{
	  //pinModeNonDue(coolingFanPin, OUTPUT); //not required as analogwrite does this automatically
	  analogWriteNonDue(coolingFanPin, 255); //inverse logic for Duet v0.6 this turns it off
	}

	InitialiseInterrupts();

	addToTime = 0.0;
	lastTimeCall = 0;
	lastTime = Time();
	longWait = lastTime;
}

void Platform::SetSlowestDrive()
{
	slowestDrive = 0;
	for(int8_t drive = 1; drive < DRIVES; drive++)
	{
		if(InstantDv(drive) < InstantDv(slowestDrive))
			slowestDrive = drive;
	}
}

void Platform::InitZProbe()
{
	zProbeOnFilter.Init(0);
	zProbeOffFilter.Init(0);

	if (nvData.zProbeType == 1 || nvData.zProbeType == 2)
	{
		pinMode(zProbeModulationPin, OUTPUT);
		digitalWrite(zProbeModulationPin, HIGH);	// enable the IR LED
		SetZProbing(false);
	}
	else if (nvData.zProbeType == 3)
	{
		pinMode(zProbeModulationPin, OUTPUT);
		digitalWrite(zProbeModulationPin, LOW);		// enable the alternate sensor
		SetZProbing(false);
	}
}

int Platform::GetRawZHeight() const
{
	return (nvData.zProbeType != 0) ? analogRead(zProbePin) : 0;
}

// Return the Z probe data.
// The ADC readings are 12 bits, so we convert them to 10-bit readings for compatibility with the old firmware.
int Platform::ZProbe() const
{
	if (zProbeOnFilter.IsValid() && zProbeOffFilter.IsValid())
	{
		switch (nvData.zProbeType)
		{
		case 1:
		case 3:
			// Simple IR sensor, or direct-mode ultrasonic sensor
			return (int) ((zProbeOnFilter.GetSum() + zProbeOffFilter.GetSum()) / (8 * numZProbeReadingsAveraged));

		case 2:
			// Modulated IR sensor. We assume that zProbeOnFilter and zprobeOffFilter average the same number of readings.
			// Because of noise, it is possible to get a negative reading, so allow for this.
			return (int) (((int32_t) zProbeOnFilter.GetSum() - (int32_t) zProbeOffFilter.GetSum())
					/ (4 * numZProbeReadingsAveraged));

		default:
			break;
		}
	}
	return 0;	// Z probe not turned on or not initialised yet
}

// Return the Z probe secondary values.
int Platform::GetZProbeSecondaryValues(int& v1, int& v2)
{
	if (zProbeOnFilter.IsValid() && zProbeOffFilter.IsValid())
	{
		switch (nvData.zProbeType)
		{
		case 2:		// modulated IR sensor
			v1 = (int) (zProbeOnFilter.GetSum() / (4 * numZProbeReadingsAveraged));	// pass back the reading with IR turned on
			return 1;
		default:
			break;
		}
	}
	return 0;
}

int Platform::GetZProbeType() const
{
	return nvData.zProbeType;
}

void Platform::SetZProbeAxes(const bool axes[AXES])
{
	for(int axis=0; axis<AXES; axis++)
	{
		nvData.zProbeAxes[axis] = axes[axis];
	}
	WriteNvData();
}

void Platform::GetZProbeAxes(bool (&axes)[AXES])
{
	for(int axis=0; axis<AXES; axis++)
	{
		axes[axis] = nvData.zProbeAxes[axis];
	}
}

float Platform::ZProbeStopHeight() const
{
	switch (nvData.zProbeType)
	{
	case 0:
		return nvData.switchZProbeParameters.GetStopHeight(GetTemperature(0));
	case 1:
	case 2:
		return nvData.irZProbeParameters.GetStopHeight(GetTemperature(0));
	case 3:
		return nvData.alternateZProbeParameters.GetStopHeight(GetTemperature(0));
	default:
		return 0;
	}
}

void Platform::SetZProbeType(int pt)
{
	int newZProbeType = (pt >= 0 && pt <= 3) ? pt : 0;
	if (newZProbeType != nvData.zProbeType)
	{
		nvData.zProbeType = newZProbeType;
		WriteNvData();
	}
	InitZProbe();
}

bool Platform::GetZProbeParameters(struct ZProbeParameters& params) const
{
	switch (nvData.zProbeType)
	{
	case 0:
		params = nvData.switchZProbeParameters;
		return true;
	case 1:
	case 2:
		params = nvData.irZProbeParameters;
		return true;
	case 3:
		params = nvData.alternateZProbeParameters;
		return true;
	default:
		return false;
	}
}

bool Platform::SetZProbeParameters(const struct ZProbeParameters& params)
{
	switch (nvData.zProbeType)
	{
	case 0:
		if (nvData.switchZProbeParameters != params)
		{
			nvData.switchZProbeParameters = params;
			WriteNvData();
		}
		return true;
	case 1:
	case 2:
		if (nvData.irZProbeParameters != params)
		{
			nvData.irZProbeParameters = params;
			WriteNvData();
		}
		return true;
	case 3:
		if (nvData.alternateZProbeParameters != params)
		{
			nvData.alternateZProbeParameters = params;
			WriteNvData();
		}
		return true;
	default:
		return false;
	}
}

// Return true if we must home X and Y before we home Z (i.e. we are using a bed probe)
bool Platform::MustHomeXYBeforeZ() const
{
	return nvData.zProbeType != 0;
}

void Platform::WriteNvData()
{
	DueFlashStorage::write(nvAddress, &nvData, sizeof(nvData));
}

void Platform::SetZProbing(bool starting)
{
}

// Note: the use of floating point time will cause the resolution to degrade over time.
// For example, 1ms time resolution will only be available for about half an hour from startup.
// Personally, I (dc42) would rather just maintain and provide the time in milliseconds in a uint32_t.
// This would wrap round after about 49 days, but that isn't difficult to handle.
float Platform::Time()
{
	unsigned long now = micros();
	if (now < lastTimeCall) // Has timer overflowed?
		addToTime += ((float) ULONG_MAX) * TIME_FROM_REPRAP;
	lastTimeCall = now;
	return addToTime + TIME_FROM_REPRAP * (float) now;
}

void Platform::Exit()
{
	Message(HOST_MESSAGE, "Platform class exited.\n");
	active = false;
}

Compatibility Platform::Emulating() const
{
	if(compatibility == reprapFirmware)
		return me;
	return compatibility;
}

void Platform::SetEmulating(Compatibility c)
{
	if(c != me && c != reprapFirmware && c != marlin)
	{
		Message(HOST_MESSAGE, "Attempt to emulate unsupported firmware.\n");
		return;
	}
	if(c == reprapFirmware)
	{
		c = me;
	}
	compatibility = c;
}

void Platform::UpdateNetworkAddress(byte dst[4], const byte src[4])
{
	bool changed = false;
	for (uint8_t i = 0; i < 4; i++)
	{
		if (dst[i] != src[i])
		{
			dst[i] = src[i];
			changed = true;
		}
	}
	if (changed)
	{
		WriteNvData();
	}
}

void Platform::SetIPAddress(byte ip[])
{
	UpdateNetworkAddress(nvData.ipAddress, ip);
}

void Platform::SetGateWay(byte gw[])
{
	UpdateNetworkAddress(nvData.gateWay, gw);
}

void Platform::SetNetMask(byte nm[])
{
	UpdateNetworkAddress(nvData.netMask, nm);
}

void Platform::Spin()
{
	if (!active)
		return;

	if (debugCode == DiagnosticTest::TestSpinLockup)
	{
		for (;;) {}
	}

	line->Spin();

	ClassReport("Platform", longWait);

}

void Platform::SoftwareReset(uint16_t reason)
{
	if (reason != 0)
	{
		if (line->inUsbWrite)
		{
			reason |= SoftwareResetReason::inUsbOutput;	// if we are resetting because we are stuck in a Spin function, record whether we are trying to send to USB
		}
		if (reprap.GetNetwork()->InLwip())
		{
			reason |= SoftwareResetReason::inLwipSpin;
		}
	}

	if (reason != 0 || reason != nvData.resetReason)
	{
		nvData.resetReason = reason;
		GetStackUsage(NULL, NULL, &nvData.neverUsedRam);
		WriteNvData();
	}

	rstc_start_software_reset(RSTC);
	for(;;) {}
}

//*****************************************************************************************************************

// Interrupts

void TC3_Handler()
{
	TC_GetStatus(TC1, 0);
	reprap.Interrupt();
}

void Platform::InitialiseInterrupts()
{
	// Timer interrupt for stepper motors
	pmc_set_writeprotect(false);
	pmc_enable_periph_clk((uint32_t) TC3_IRQn);
	TC_Configure(TC1, 0, TC_CMR_WAVE | TC_CMR_WAVSEL_UP_RC | TC_CMR_TCCLKS_TIMER_CLOCK4);
	TC1 ->TC_CHANNEL[0].TC_IER = TC_IER_CPCS;
	TC1 ->TC_CHANNEL[0].TC_IDR = ~TC_IER_CPCS;
	SetInterrupt(STANDBY_INTERRUPT_RATE);

	// Tick interrupt for ADC conversions
	tickState = 0;
	currentHeater = 0;

	active = true;							// this enables the tick interrupt, which keeps the watchdog happy
}

//void Platform::DisableInterrupts()
//{
//	NVIC_DisableIRQ(TC3_IRQn);
//}

// Process a 1ms tick interrupt
// This function must be kept fast so as not to disturb the stepper timing, so don't do any floating point maths in here.
// This is what we need to do:
// 0.  Kick the watchdog.
// 1.  Kick off a new ADC conversion.
// 2.  Fetch and process the result of the last ADC conversion.
// 3a. If the last ADC conversion was for the Z probe, toggle the modulation output if using a modulated IR sensor.
// 3b. If the last ADC reading was a thermistor reading, check for an over-temperature situation and turn off the heater if necessary.
//     We do this here because the usual polling loop sometimes gets stuck trying to send data to the USB port.

//#define TIME_TICK_ISR	1		// define this to store the tick ISR time in errorCodeBits

void Platform::Tick()
{
#ifdef TIME_TICK_ISR
	uint32_t now = micros();
#endif
	switch (tickState)
	{
	case 1:			// last conversion started was a thermistor
	case 3:
	{
		ThermistorAveragingFilter& currentFilter = const_cast<ThermistorAveragingFilter&>(thermistorFilters[currentHeater]);
		currentFilter.ProcessReading(GetAdcReading(heaterAdcChannels[currentHeater]));
		StartAdcConversion(zProbeAdcChannel);
		if (currentFilter.IsValid())
		{
			uint32_t sum = currentFilter.GetSum();
			if (sum < thermistorOverheatSums[currentHeater] || sum >= adDisconnectedReal * numThermistorReadingsAveraged)
			{
				// We have an over-temperature or bad reading from this thermistor, so turn off the heater
				// NB - the SetHeater function we call does floating point maths, but this is an exceptional situation so we allow it
				SetHeater(currentHeater, 0.0);
				errorCodeBits |= ErrorBadTemp;
			}
		}
		++currentHeater;
		if (currentHeater == HEATERS)
		{
			currentHeater = 0;
		}
	}
		++tickState;
		break;

	case 2:			// last conversion started was the Z probe, with IR LED on
		const_cast<ZProbeAveragingFilter&>(zProbeOnFilter).ProcessReading(GetAdcReading(zProbeAdcChannel));
		StartAdcConversion(heaterAdcChannels[currentHeater]);	// read a thermistor
		if (nvData.zProbeType == 2)								// if using a modulated IR sensor
		{
			digitalWrite(Z_PROBE_MOD_PIN, LOW);					// turn off the IR emitter
		}
		++tickState;
		break;

	case 4:			// last conversion started was the Z probe, with IR LED off if modulation is enabled
		const_cast<ZProbeAveragingFilter&>(zProbeOffFilter).ProcessReading(GetAdcReading(zProbeAdcChannel));
		// no break
	case 0:			// this is the state after initialisation, no conversion has been started
	default:
		StartAdcConversion(heaterAdcChannels[currentHeater]);	// read a thermistor
		if (nvData.zProbeType == 2)								// if using a modulated IR sensor
		{
			digitalWrite(Z_PROBE_MOD_PIN, HIGH);				// turn on the IR emitter
		}
		tickState = 1;
		break;
	}
#ifdef TIME_TICK_ISR
	uint32_t now2 = micros();
	if (now2 - now > errorCodeBits)
	{
		errorCodeBits = now2 - now;
	}
#endif
}

/*static*/uint16_t Platform::GetAdcReading(adc_channel_num_t chan)
{
	uint16_t rslt = (uint16_t) adc_get_channel_value(ADC, chan);
	adc_disable_channel(ADC, chan);
	return rslt;
}

/*static*/void Platform::StartAdcConversion(adc_channel_num_t chan)
{
	adc_enable_channel(ADC, chan);
	adc_start(ADC );
}

// Convert an Arduino Due pin number to the corresponding ADC channel number
/*static*/adc_channel_num_t Platform::PinToAdcChannel(int pin)
{
	if (pin < A0)
	{
		pin += A0;
	}
	return (adc_channel_num_t) (int) g_APinDescription[pin].ulADCChannelNumber;
}

//*************************************************************************************************

// This diagnostics function is the first to be called, so it calls Message to start with.
// All other messages generated by this and other diagnostics functions must call AppendMessage.
void Platform::Diagnostics()
{
	Message(BOTH_MESSAGE, "Platform Diagnostics:\n");

	// Print memory stats and error codes to USB and copy them to the current webserver reply
	const char *ramstart = (char *) 0x20070000;
	const struct mallinfo mi = mallinfo();
	AppendMessage(BOTH_MESSAGE, "Memory usage:\n\n");
	scratchString.printf("Program static ram used: %d\n", &_end - ramstart);
	AppendMessage(BOTH_MESSAGE, scratchString);
	scratchString.printf("Dynamic ram used: %d\n", mi.uordblks);
	AppendMessage(BOTH_MESSAGE, scratchString);
	scratchString.printf("Recycled dynamic ram: %d\n", mi.fordblks);
	AppendMessage(BOTH_MESSAGE, scratchString);
	size_t currentStack, maxStack, neverUsed;
	GetStackUsage(&currentStack, &maxStack, &neverUsed);
	scratchString.printf("Current stack ram used: %d\n", currentStack);
	AppendMessage(BOTH_MESSAGE, scratchString);
	scratchString.printf("Maximum stack ram used: %d\n", maxStack);
	AppendMessage(BOTH_MESSAGE, scratchString);
	scratchString.printf("Never used ram: %d\n", neverUsed);
	AppendMessage(BOTH_MESSAGE, scratchString);

	// Show the up time and reason for the last reset
	const uint32_t now = (uint32_t)Time();		// get up time in seconds
	const char* resetReasons[8] = { "power up", "backup", "watchdog", "software", "external", "?", "?", "?" };
	scratchString.printf("Last reset %02d:%02d:%02d ago, cause: %s\n",
			(unsigned int)(now/3600), (unsigned int)((now % 3600)/60), (unsigned int)(now % 60),
			resetReasons[(REG_RSTC_SR & RSTC_SR_RSTTYP_Msk) >> RSTC_SR_RSTTYP_Pos]);
	AppendMessage(BOTH_MESSAGE, scratchString);

	// Show the error code stored at the last software reset
	scratchString.printf("Last software reset code & available RAM: 0x%04x, %u\n", nvData.resetReason, nvData.neverUsedRam);
	AppendMessage(BOTH_MESSAGE, scratchString);

	// Show the current error codes
	scratchString.printf("Error status: %u\n", errorCodeBits);
	AppendMessage(BOTH_MESSAGE, scratchString);

	// Show the current probe position heights
	scratchString.copy("Bed probe heights:");
	for (size_t i = 0; i < NUMBER_OF_PROBE_POINTS; ++i)
	{
		scratchString.catf(" %.3f", reprap.GetMove()->ZBedProbePoint(i));
	}
	scratchString.cat("\n");
	AppendMessage(BOTH_MESSAGE, scratchString);

	// Show the number of free entries in the file table
	unsigned int numFreeFiles = 0;
	for (int8_t i = 0; i < MAX_FILES; i++)
	{
		if (!files[i]->inUse)
		{
			++numFreeFiles;
		}
	}
	scratchString.printf("Free file entries: %u\n", numFreeFiles);
	AppendMessage(BOTH_MESSAGE, scratchString);

	// Show the longest write time
	scratchString.printf("Longest block write time: %.1fms\n", FileStore::GetAndClearLongestWriteTime());
	AppendMessage(BOTH_MESSAGE, scratchString);

	reprap.Timing();

#if LWIP_STATS
	// Normally we should NOT try to display LWIP stats here, because it uses debugPrintf(), which will hang the system is no USB cable is connected.
	if (reprap.Debug())
	{
		stats_display();
	}
#endif
}

void Platform::DiagnosticTest(int d)
{
	switch (d)
	{
	case DiagnosticTest::TestWatchdog:
		SysTick ->CTRL &= ~(SysTick_CTRL_TICKINT_Msk);	// disable the system tick interrupt so that we get a watchdog timeout reset
		break;

	case DiagnosticTest::TestSpinLockup:
		debugCode = d;									// tell the Spin function to loop
		break;
	default:
		break;
	}
}

// Return the stack usage and amount of memory that has never been used, in bytes
void Platform::GetStackUsage(size_t* currentStack, size_t* maxStack, size_t* neverUsed) const
{
	const char *ramend = (const char *) 0x20088000;
	register const char * stack_ptr asm ("sp");
	const char *heapend = sbrk(0);
	const char* stack_lwm = heapend;
	while (stack_lwm < stack_ptr && *stack_lwm == memPattern)
	{
		++stack_lwm;
	}
	if (currentStack) { *currentStack = ramend - stack_ptr; }
	if (maxStack) { *maxStack = ramend - stack_lwm; }
	if (neverUsed) { *neverUsed = stack_lwm - heapend; }
}

void Platform::ClassReport(char* className, float &lastTime)
{
	if (!reprap.Debug())
		return;
	if (Time() - lastTime < LONG_TIME)
		return;
	lastTime = Time();
	scratchString.printf("Class %s spinning.\n", className);
	Message(HOST_MESSAGE, scratchString);
}

//===========================================================================
//=============================Thermal Settings  ============================
//===========================================================================

// See http://en.wikipedia.org/wiki/Thermistor#B_or_.CE.B2_parameter_equation

// BETA is the B value
// RS is the value of the series resistor in ohms
// R_INF is R0.exp(-BETA/T0), where R0 is the thermistor resistance at T0 (T0 is in kelvin)
// Normally T0 is 298.15K (25 C).  If you write that expression in brackets in the #define the compiler 
// should compute it for you (i.e. it won't need to be calculated at run time).

// If the A->D converter has a range of 0..1023 and the measured voltage is V (between 0 and 1023)
// then the thermistor resistance, R = V.RS/(1024 - V)
// and the temperature, T = BETA/ln(R/R_INF)
// To get degrees celsius (instead of kelvin) add -273.15 to T

// Result is in degrees celsius

float Platform::GetTemperature(size_t heater) const
{
	int rawTemp = GetRawTemperature(heater);

	// If the ADC reading is N then for an ideal ADC, the input voltage is at least N/(AD_RANGE + 1) and less than (N + 1)/(AD_RANGE + 1), times the analog reference.
	// So we add 0.5 to to the reading to get a better estimate of the input.

	float reading = (float) rawTemp + 0.5;

	// Recognise the special case of thermistor disconnected.
	// For some ADCs, the high-end offset is negative, meaning that the ADC never returns a high enough value. We need to allow for this here.

	const PidParameters& p = nvData.pidParams[heater];
	if (p.adcHighOffset < 0.0)
	{
		rawTemp -= (int) p.adcHighOffset;
	}
	if (rawTemp >= adDisconnectedVirtual)
	{
		return ABS_ZERO;		// thermistor is disconnected
	}

	// Correct for the low and high ADC offsets
	reading -= p.adcLowOffset;
	reading *= (adRangeVirtual + 1) / (adRangeVirtual + 1 + p.adcHighOffset - p.adcLowOffset);

	float resistance = reading * p.thermistorSeriesR / ((adRangeVirtual + 1) - reading);
	return (resistance <= p.GetRInf()) ? 2000.0			// thermistor short circuit, return a high temperature
			: ABS_ZERO + p.GetBeta() / log(resistance / p.GetRInf());
}

void Platform::SetPidParameters(size_t heater, const PidParameters& params)
{
	if (heater < HEATERS && params != nvData.pidParams[heater])
	{
		nvData.pidParams[heater] = params;
		WriteNvData();
	}
}
const PidParameters& Platform::GetPidParameters(size_t heater)
{
	return nvData.pidParams[heater];
}

// power is a fraction in [0,1]

void Platform::SetHeater(size_t heater, const float& power)
{
	if (heatOnPins[heater] < 0)
		return;

	byte p = (byte) (255.0 * min<float>(1.0, max<float>(0.0, power)));
	if (HEAT_ON == 0)
	{
		p = 255 - p;
		if(heater == E0_HEATER || heater == E1_HEATER) //HEAT_ON_PINS {6, X5, X7, 7, 8, 9}
  		{
			analogWriteNonDue(heatOnPins[heater], p);
		}
		else
		{
			analogWrite(heatOnPins[heater], p);
		}
	 }
}

EndStopHit Platform::Stopped(int8_t drive)
{
	if (nvData.zProbeType > 0 && drive < AXES && nvData.zProbeAxes[drive])
	{
		int zProbeVal = ZProbe();
		int zProbeADValue =
				(nvData.zProbeType == 3) ?
						nvData.alternateZProbeParameters.adcValue : nvData.irZProbeParameters.adcValue;
		if (zProbeVal >= zProbeADValue)
			return lowHit;
		else if (zProbeVal * 10 >= zProbeADValue * 9)	// if we are at/above 90% of the target value
			return lowNear;
		else
			return noStop;
	}

	if (lowStopPins[drive] >= 0)
	{
		if (digitalRead(lowStopPins[drive]) == ENDSTOP_HIT)
			return lowHit;
	}
	if (highStopPins[drive] >= 0)
	{
		if (digitalRead(highStopPins[drive]) == ENDSTOP_HIT)
			return highHit;
	}
	return noStop;
}

void Platform::SetDirection(byte drive, bool direction)
{
	if(directionPins[drive] < 0)
		return;
	if(drive == E0_DRIVE) //DIRECTION_PINS {15, 26, 4, X3, 35, 53, 51, 48}
	{
		digitalWriteNonDue(directionPins[drive], direction);
	}
	else
	{
		digitalWrite(directionPins[drive], direction);
	}
}

void Platform::Disable(byte drive)
{
	if(enablePins[drive] < 0)
		  return;
	if(drive == Z_AXIS || drive==E0_DRIVE || drive==E2_DRIVE) //ENABLE_PINS {29, 27, X1, X0, 37, X8, 50, 47}
		digitalWriteNonDue(enablePins[drive], DISABLE);
	else
		digitalWrite(enablePins[drive], DISABLE);
	driveEnabled[drive] = false;
}

void Platform::Step(byte drive)
{
	if(stepPins[drive] < 0)
		return;
	if(!driveEnabled[drive] && enablePins[drive] >= 0)
	{
		if(drive == Z_AXIS || drive==E0_DRIVE || drive==E2_DRIVE) //ENABLE_PINS {29, 27, X1, X0, 37, X8, 50, 47}
			digitalWriteNonDue(enablePins[drive], ENABLE);
		else
			digitalWrite(enablePins[drive], ENABLE);
		driveEnabled[drive] = true;
	}
	if(drive == E0_DRIVE || drive == E3_DRIVE) //STEP_PINS {14, 25, 5, X2, 41, 39, X4, 49}
	{
		digitalWriteNonDue(stepPins[drive], 0);
		digitalWriteNonDue(stepPins[drive], 1);
	} else
	{
		digitalWrite(stepPins[drive], 0);
		digitalWrite(stepPins[drive], 1);
	}
}

// current is in mA

void Platform::SetMotorCurrent(byte drive, float current)
{
	unsigned short pot = (unsigned short)(0.256*current*8.0*senseResistor/maxStepperDigipotVoltage);
//	Message(HOST_MESSAGE, "Set pot to: ");
//	snprintf(scratchString, STRING_LENGTH, "%d", pot);
//	Message(HOST_MESSAGE, scratchString);
//	Message(HOST_MESSAGE, "\n");
	if(drive < 4)
	{
		mcpDuet.setNonVolatileWiper(potWipes[drive], pot);
		mcpDuet.setVolatileWiper(potWipes[drive], pot);
	}
	else
	{
		mcpExpansion.setNonVolatileWiper(potWipes[drive], pot);
		mcpExpansion.setVolatileWiper(potWipes[drive], pot);
	}
}


float Platform::MotorCurrent(byte drive)
{
	unsigned short pot;
	if (drive < 4)
	{
		pot = mcpDuet.getNonVolatileWiper(potWipes[drive]);
	}
	else
	{
		pot = mcpExpansion.getNonVolatileWiper(potWipes[drive]);
	}

	return (float)pot * maxStepperDigipotVoltage / (0.256 * 8.0 * senseResistor);
}

// This is a bit of a compromise - old RepRaps used fan speeds in the range
// [0, 255], which is very hardware dependent.  It makes much more sense
// to specify speeds in [0.0, 1.0].  This looks at the value supplied (which
// the G Code reader will get right for a float or an int) and attempts to
// do the right thing whichever the user has done.  This will only not work
// for an old-style fan speed of 1/255...

void Platform::CoolingFan(float speed)
{
	if(coolingFanPin >= 0)
	{
		byte p;

		if(speed <= 1.0)
		{
			p = (byte)(255.0 * max<float>(0.0, speed));
		}
		else
		{
			p = (byte)speed;
		}

		// The cooling fan output pin gets inverted if HEAT_ON == 0
		analogWriteNonDue(coolingFanPin, (HEAT_ON == 0) ? (255 - p) : p);
	}
}

// Interrupts

void Platform::SetInterrupt(float s) // Seconds
{
	if (s <= 0.0)
	{
		//NVIC_DisableIRQ(TC3_IRQn);
		Message(HOST_MESSAGE, "Negative interrupt!\n");
		s = STANDBY_INTERRUPT_RATE;
	}
	uint32_t rc = (uint32_t)( (((long)(TIME_TO_REPRAP*s))*84l)/128l );
	TC_SetRA(TC1, 0, rc/2); //50% high, 50% low
	TC_SetRC(TC1, 0, rc);
	TC_Start(TC1, 0);
	NVIC_EnableIRQ(TC3_IRQn);
}

//-----------------------------------------------------------------------------------------------------

FileStore* Platform::GetFileStore(const char* directory, const char* fileName, bool write)
{
	if (!fileStructureInitialised)
		return NULL;

	for (int i = 0; i < MAX_FILES; i++)
	{
		if (!files[i]->inUse)
		{
			files[i]->inUse = true;
			if (files[i]->Open(directory, fileName, write))
			{
				return files[i];
			}
			else
			{
				files[i]->inUse = false;
				return NULL;
			}
		}
	}
	Message(HOST_MESSAGE, "Max open file count exceeded.\n");
	return NULL;
}

MassStorage* Platform::GetMassStorage()
{
	return massStorage;
}

void Platform::Message(char type, const char* message)
{
	switch(type)
	{
	case FLASH_LED:
		// Message that is to flash an LED; the next two bytes define
		// the frequency and M/S ratio.

		break;

	case DISPLAY_MESSAGE:
		// Message that is to appear on a local display;  \f and \n should be supported.
		break;

	case HOST_MESSAGE:
	case DEBUG_MESSAGE:
		// Message that is to be sent to the host via USB; the H is not sent.
		if (line->GetOutputColumn() == 0)
		{
			for(uint8_t i = 0; i < messageIndent; i++)
			{
				line->Write(' ', type == DEBUG_MESSAGE);
			}
		}
		line->Write(message, type == DEBUG_MESSAGE);
		break;

	case WEB_MESSAGE:
		// Message that is to be sent to the web
		reprap.GetWebserver()->MessageStringToWebInterface(message, false);
		break;

	case WEB_ERROR_MESSAGE:
		// Message that is to be sent to the web - flags an error
		reprap.GetWebserver()->MessageStringToWebInterface(message, true);
		break;

	case BOTH_MESSAGE:
		// Message that is to be sent to the web & host
		if (line->GetOutputColumn() == 0)
		{
			for(uint8_t i = 0; i < messageIndent; i++)
			{
				line->Write(' ');
			}
		}
		line->Write(message);
		reprap.GetWebserver()->MessageStringToWebInterface(message, false);
		break;

	case BOTH_ERROR_MESSAGE:
		// Message that is to be sent to the web & host - flags an error
		// Make this the default behaviour too.

	default:
		if (line->GetOutputColumn() == 0)
		{
			for(uint8_t i = 0; i < messageIndent; i++)
			{
				line->Write(' ');
			}
		}
		line->Write(message);
		reprap.GetWebserver()->MessageStringToWebInterface(message, true);
		break;
	}
}

void Platform::AppendMessage(char type, const char* message)
{
	switch(type)
	{
	case FLASH_LED:
		// Message that is to flash an LED; the next two bytes define
		// the frequency and M/S ratio.

		break;

	case DISPLAY_MESSAGE:
		// Message that is to appear on a local display;  \f and \n should be supported.

		break;

	case HOST_MESSAGE:
	case DEBUG_MESSAGE:
		// Message that is to be sent to the host via USB; the H is not sent.
		if (line->GetOutputColumn() == 0)
		{
			for(uint8_t i = 0; i < messageIndent; i++)
			{
				line->Write(' ', type == DEBUG_MESSAGE);
			}
		}
		line->Write(message, type == DEBUG_MESSAGE);
		break;

	case WEB_MESSAGE:
		// Message that is to be sent to the web
		reprap.GetWebserver()->AppendReplyToWebInterface(message, false);
		break;

	case WEB_ERROR_MESSAGE:
		// Message that is to be sent to the web - flags an error
		reprap.GetWebserver()->AppendReplyToWebInterface(message, true);
		break;

	case BOTH_MESSAGE:
		// Message that is to be sent to the web & host
		if (line->GetOutputColumn() == 0)
		{
			for(uint8_t i = 0; i < messageIndent; i++)
			{
				line->Write(' ');
			}
		}
		line->Write(message);
		reprap.GetWebserver()->AppendReplyToWebInterface(message, false);
		break;

	case BOTH_ERROR_MESSAGE:
		// Message that is to be sent to the web & host - flags an error
		// Make this the default behaviour too.

	default:
		if (line->GetOutputColumn() == 0)
		{
			for(uint8_t i = 0; i < messageIndent; i++)
			{
				line->Write(' ');
			}
		}
		line->Write(message);
		reprap.GetWebserver()->AppendReplyToWebInterface(message, true);
		break;
	}
}


void Platform::SetAtxPower(bool on)
{
	digitalWrite(atxPowerPin, (on) ? HIGH : LOW);
}


/*********************************************************************************

 Files & Communication

 */

MassStorage::MassStorage(Platform* p)
{
	platform = p;
}

void MassStorage::Init()
{
	hsmciPinsinit();
	// Initialize SD MMC stack
	sd_mmc_init();
	delay(20);
	int sdPresentCount = 0;
	while ((CTRL_NO_PRESENT == sd_mmc_check(0)) && (sdPresentCount < 5))
	{
		//platform->Message(HOST_MESSAGE, "Please plug in the SD card.\n");
		//delay(1000);
		sdPresentCount++;
	}

	if (sdPresentCount >= 5)
	{
		platform->Message(HOST_MESSAGE, "Can't find the SD card.\n");
		return;
	}

	//print card info

//	SerialUSB.print("sd_mmc_card->capacity: ");
//	SerialUSB.print(sd_mmc_get_capacity(0));
//	SerialUSB.print(" bytes\n");
//	SerialUSB.print("sd_mmc_card->clock: ");
//	SerialUSB.print(sd_mmc_get_bus_clock(0));
//	SerialUSB.print(" Hz\n");
//	SerialUSB.print("sd_mmc_card->bus_width: ");
//	SerialUSB.println(sd_mmc_get_bus_width(0));

	memset(&fileSystem, 0, sizeof(FATFS));
	//f_mount (LUN_ID_SD_MMC_0_MEM, NULL);
	//int mounted = f_mount(LUN_ID_SD_MMC_0_MEM, &fileSystem);
	int mounted = f_mount(0, &fileSystem);
	if (mounted != FR_OK)
	{
		platform->Message(HOST_MESSAGE, "Can't mount filesystem 0: code ");
		snprintf(scratchString, STRING_LENGTH, "%d", mounted);
		platform->Message(HOST_MESSAGE, scratchString);
		platform->Message(HOST_MESSAGE, "\n");
	}
}

const char* MassStorage::CombineName(const char* directory, const char* fileName)
{
	int out = 0;
	int in = 0;

	if (directory != NULL)
	{
		while (directory[in] != 0 && directory[in] != '\n')
		{
			scratchString[out] = directory[in];
			in++;
			out++;
			if (out >= STRING_LENGTH)
			{
				platform->Message(HOST_MESSAGE, "CombineName() buffer overflow.");
				out = 0;
			}
		}
	}

	if (in > 0 && directory[in -1] != '/' && out < STRING_LENGTH -1)
	{
		scratchString[out] = '/';
		out++;
	}

	in = 0;
	while (fileName[in] != 0 && fileName[in] != '\n')
	{
		scratchString[out] = fileName[in];
		in++;
		out++;
		if (out >= STRING_LENGTH)
		{
			platform->Message(HOST_MESSAGE, "CombineName() buffer overflow.");
			out = 0;
		}
	}
	scratchString[out] = 0;

	return scratchString;
}

// Open a directory to read a file list. Returns true if it contains any files, false otherwise.
bool MassStorage::FindFirst(const char *directory, FileInfo &file_info)
{
	TCHAR loc[64 + 1];

	// Remove the trailing '/' from the directory name
	size_t len = strnlen(directory, ARRAY_SIZE(loc) - 1);	// the -1 ensures we have room for a null terminator
	if (len == 0)
	{
		loc[0] = 0;
	}
	else if (directory[len - 1] == '/')
	{
		strncpy(loc, directory, len - 1);
		loc[len - 1] = 0;
	}
	else
	{
		strncpy(loc, directory, len);
		loc[len] = 0;
	}

	FRESULT res = f_opendir(&findDir, loc);
	if (res == FR_OK)
	{
		FILINFO entry;
		entry.lfname = file_info.fileName;
		entry.lfsize = ARRAY_SIZE(file_info.fileName);

		for(;;)
		{
			res = f_readdir(&findDir, &entry);
			if (res != FR_OK || entry.fname[0] == 0) break;
			if (StringEquals(entry.fname, ".") || StringEquals(entry.fname, "..")) continue;

			file_info.isDirectory = (entry.fattrib & AM_DIR);
			file_info.size = entry.fsize;
			uint16_t day = entry.fdate & 0x1F;
			if (day == 0)
			{
				// This can happen if a transfer hasn't been processed completely.
				day = 1;
			}
			file_info.day = day;
			file_info.month = (entry.fdate & 0x01E0) >> 5;
			file_info.year = (entry.fdate >> 9) + 1980;
			if (file_info.fileName[0] == 0)
			{
				strncpy(file_info.fileName, entry.fname, ARRAY_SIZE(file_info.fileName));
			}

			return true;
		}
	}

	return false;
}

// Find the next file in a directory. Returns true if another file has been read.
bool MassStorage::FindNext(FileInfo &file_info)
{
	FILINFO entry;
	entry.lfname = file_info.fileName;
	entry.lfsize = ARRAY_SIZE(file_info.fileName);

	if (f_readdir(&findDir, &entry) != FR_OK || entry.fname[0] == 0)
	{
		//f_closedir(findDir);
		return false;
	}

	file_info.isDirectory = (entry.fattrib & AM_DIR);
	file_info.size = entry.fsize;
	uint16_t day = entry.fdate & 0x1F;
	if (day == 0)
	{
		// This can happen if a transfer hasn't been processed completely.
		day = 1;
	}
	file_info.day = day;
	file_info.month = (entry.fdate & 0x01E0) >> 5;
	file_info.year = (entry.fdate >> 9) + 1980;
	if (file_info.fileName[0] == 0)
	{
		strncpy(file_info.fileName, entry.fname, ARRAY_UPB(file_info.fileName));
	}

	return true;
}

// Month names. The first entry is used for invalid month numbers.
static const char *monthNames[13] = { "???", "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

// Returns the name of the specified month or '???' if the specified value is invalid.
const char* MassStorage::GetMonthName(const uint8_t month)
{
	return (month <= 12) ? monthNames[month] : monthNames[0];
}

// Delete a file or directory
bool MassStorage::Delete(const char* directory, const char* fileName)
{
	const char* location = (directory != NULL)
							? platform->GetMassStorage()->CombineName(directory, fileName)
								: fileName;
	if (f_unlink(location) != FR_OK)
	{
		platform->Message(HOST_MESSAGE, "Can't delete file ");
		platform->Message(HOST_MESSAGE, location);
		platform->Message(HOST_MESSAGE, "\n");
		return false;
	}
	return true;
}

// Create a new directory
bool MassStorage::MakeDirectory(const char *parentDir, const char *dirName)
{
	const char* location = platform->GetMassStorage()->CombineName(parentDir, dirName);
	if (f_mkdir(location) != FR_OK)
	{
		platform->Message(HOST_MESSAGE, "Can't create directory ");
		platform->Message(HOST_MESSAGE, location);
		platform->Message(HOST_MESSAGE, "\n");
		return false;
	}
	return true;
}

bool MassStorage::MakeDirectory(const char *directory)
{
	if (f_mkdir(directory) != FR_OK)
	{
		platform->Message(HOST_MESSAGE, "Can't create directory ");
		platform->Message(HOST_MESSAGE, directory);
		platform->Message(HOST_MESSAGE, "\n");
		return false;
	}
	return true;
}

// Rename a file or directory
bool MassStorage::Rename(const char *oldFilename, const char *newFilename)
{
	if (f_rename(oldFilename, newFilename) != FR_OK)
	{
		platform->Message(HOST_MESSAGE, "Can't rename file or directory ");
		platform->Message(HOST_MESSAGE, oldFilename);
		platform->Message(HOST_MESSAGE, " to ");
		platform->Message(HOST_MESSAGE, newFilename);
		platform->Message(HOST_MESSAGE, "\n");
		return false;
	}
	return true;
}

// Check if the specified directory exists
bool MassStorage::PathExists(const char *path) const
{
	DIR dir;
	return (f_opendir(&dir, path) == FR_OK);
}

//------------------------------------------------------------------------------------------------

FileStore::FileStore(Platform* p) : platform(p)
{
}

void FileStore::Init()
{
	bufferPointer = 0;
	inUse = false;
	writing = false;
	lastBufferEntry = 0;
	openCount = 0;
}

// Open a local file (for example on an SD card).
// This is protected - only Platform can access it.

bool FileStore::Open(const char* directory, const char* fileName, bool write)
{
	const char* location = (directory != NULL)
							? platform->GetMassStorage()->CombineName(directory, fileName)
								: fileName;

	writing = write;
	lastBufferEntry = FILE_BUF_LEN - 1;
	FRESULT openReturn;

	if (writing)
	{
		openReturn = f_open(&file, location, FA_CREATE_ALWAYS | FA_WRITE);
		if (openReturn != FR_OK)
		{
			char errString[10];		// don't use scratch_string for this because that may be holding the original filename
			platform->Message(HOST_MESSAGE, "Can't open ");
			platform->Message(HOST_MESSAGE, location);
			platform->Message(HOST_MESSAGE, " to write to, error code ");
			snprintf(errString, ARRAY_SIZE(errString), "%d", openReturn);
			platform->Message(HOST_MESSAGE, errString);
			platform->Message(HOST_MESSAGE, "\n");
			return false;
		}
		bufferPointer = 0;
	}
	else
	{
		openReturn = f_open(&file, location, FA_OPEN_EXISTING | FA_READ);
		if (openReturn != FR_OK)
		{
			char errString[10];		// don't use scratch_string for this because that may be holding the original filename
			platform->Message(HOST_MESSAGE, "Can't open ");
			platform->Message(HOST_MESSAGE, location);
			platform->Message(HOST_MESSAGE, " to read from, error code ");
			snprintf(errString, ARRAY_SIZE(errString), "%d", openReturn);
			platform->Message(HOST_MESSAGE, errString);
			platform->Message(HOST_MESSAGE, "\n");
			return false;
		}
		bufferPointer = FILE_BUF_LEN;
	}

	inUse = true;
	openCount = 1;
	return true;
}

void FileStore::Duplicate()
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to dup a non-open file.\n");
		return;
	}
	++openCount;
}

bool FileStore::Close()
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to close a non-open file.\n");
		return false;
	}
	--openCount;
	if (openCount != 0)
	{
		return true;
	}
	bool ok = true;
	if (writing)
	{
		ok = Flush();
	}
	FRESULT fr = f_close(&file);
	inUse = false;
	writing = false;
	lastBufferEntry = 0;
	return ok && fr == FR_OK;
}

bool FileStore::Seek(unsigned long pos)
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to seek on a non-open file.\n");
		return false;
	}
	if (writing)
	{
		WriteBuffer();
	}
	FRESULT fr = f_lseek(&file, pos);
	bufferPointer = (writing) ? 0 : FILE_BUF_LEN;
	return fr == FR_OK;
}

bool FileStore::GoToEnd()
{
	return Seek(Length());
}

unsigned long FileStore::Length()
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to size non-open file.\n");
		return 0;
	}
	return file.fsize;
}

int8_t FileStore::Status()
{
	if (!inUse)
		return nothing;

	if (lastBufferEntry == FILE_BUF_LEN)
		return byteAvailable;

	if (bufferPointer < lastBufferEntry)
		return byteAvailable;

	return nothing;
}

bool FileStore::ReadBuffer()
{
	FRESULT readStatus = f_read(&file, buf, FILE_BUF_LEN, &lastBufferEntry);	// Read a chunk of file
	if (readStatus)
	{
		platform->Message(HOST_MESSAGE, "Error reading file.\n");
		return false;
	}
	bufferPointer = 0;
	return true;
}

// Single character read via the buffer
bool FileStore::Read(char& b)
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to read from a non-open file.\n");
		return false;
	}

	if (bufferPointer >= FILE_BUF_LEN)
	{
		bool ok = ReadBuffer();
		if (!ok)
		{
			return false;
		}
	}

	if (bufferPointer >= lastBufferEntry)
	{
		b = 0;  // Good idea?
		return false;
	}

	b = (char) buf[bufferPointer];
	bufferPointer++;

	return true;
}

// Block read, doesn't use the buffer
int FileStore::Read(char* extBuf, unsigned int nBytes)
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to read from a non-open file.\n");
		return -1;
	}
	bufferPointer = FILE_BUF_LEN;	// invalidate the buffer
	UINT bytesRead;
	FRESULT readStatus = f_read(&file, extBuf, nBytes, &bytesRead);
	if (readStatus)
	{
		platform->Message(HOST_MESSAGE, "Error reading file.\n");
		return -1;
	}
	return (int)bytesRead;
}

bool FileStore::WriteBuffer()
{
	if (bufferPointer != 0)
	{
		bool ok = InternalWriteBlock((const char*)buf, bufferPointer);
		if (!ok)
		{
			platform->Message(HOST_MESSAGE, "Error writing file.  Disc may be full.\n");
			return false;
		}
		bufferPointer = 0;
	}
	return true;
}

bool FileStore::Write(char b)
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to write byte to a non-open file.\n");
		return false;
	}
	buf[bufferPointer] = b;
	bufferPointer++;
	if (bufferPointer >= FILE_BUF_LEN)
	{
		return WriteBuffer();
	}
	return true;
}

bool FileStore::Write(const char* b)
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to write string to a non-open file.\n");
		return false;
	}
	int i = 0;
	while (b[i])
	{
		if (!Write(b[i++]))
		{
			return false;
		}
	}
	return true;
}

// Direct block write that bypasses the buffer. Used when uploading files.
bool FileStore::Write(const char *s, unsigned int len)
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to write block to a non-open file.\n");
		return false;
	}
	if (!WriteBuffer())
	{
		return false;
	}
	InternalWriteBlock(s, len);
}

bool FileStore::InternalWriteBlock(const char *s, unsigned int len)
{
	unsigned int bytesWritten;
	uint32_t time = micros();
	FRESULT writeStatus = f_write(&file, s, len, &bytesWritten);
	time = micros() - time;
	if (time > longestWriteTime)
	{
		longestWriteTime = time;
	}
	if ((writeStatus != FR_OK) || (bytesWritten != len))
	{
		platform->Message(HOST_MESSAGE, "Error writing file.  Disc may be full.\n");
		return false;
	}
	return true;
}

bool FileStore::Flush()
{
	if (!inUse)
	{
		platform->Message(HOST_MESSAGE, "Attempt to flush a non-open file.\n");
		return false;
	}
	if (!WriteBuffer())
	{
		return false;
	}
	return f_sync(&file) == FR_OK;
}

float FileStore::GetAndClearLongestWriteTime()
{
	float ret = (float)longestWriteTime/1000.0;
	longestWriteTime = 0;
	return ret;
}

uint32_t FileStore::longestWriteTime = 0;

//***************************************************************************************************

// Serial/USB class

Line::Line()
{
}

int8_t Line::Status() const
{
//	if(alternateInput != NULL)
//		return alternateInput->Status();
	return inputNumChars == 0 ? nothing : byteAvailable;
}

// This is only ever called on initialisation, so we
// know the buffer won't overflow

void Line::InjectString(char* string)
{
	int i = 0;
	while(string[i])
	{
		inBuffer[(inputGetIndex + inputNumChars) % lineInBufsize] = string[i];
		inputNumChars++;
		i++;
	}
}

int Line::Read(char& b)
{
//  if(alternateInput != NULL)
//	return alternateInput->Read(b);

	if (inputNumChars == 0)
		return 0;
	b = inBuffer[inputGetIndex];
	inputGetIndex = (inputGetIndex + 1) % lineInBufsize;
	--inputNumChars;
	return 1;
}

void Line::Init()
{
	inputGetIndex = 0;
	inputNumChars = 0;
	outputGetIndex = 0;
	outputNumChars = 0;
	ignoringOutputLine = false;
	SerialUSB.begin(BAUD_RATE);
	inUsbWrite = false;
	outputColumn = 0;
}

void Line::Spin()
{
	// Read the serial data in blocks to avoid excessive flow control
	if (inputNumChars <= lineInBufsize / 2)
	{
		int16_t target = SerialUSB.available() + (int16_t) inputNumChars;
		if (target > lineInBufsize)
		{
			target = lineInBufsize;
		}
		while ((int16_t) inputNumChars < target)
		{
			int incomingByte = SerialUSB.read();
			if (incomingByte < 0)
				break;
			inBuffer[(inputGetIndex + inputNumChars) % lineInBufsize] = (char) incomingByte;
			++inputNumChars;
		}
	}

	TryFlushOutput();
}

// Write a character to USB.
// If 'block' is true then we don't return until we have either written it to the USB port or put it in the buffer.
// Otherwise, if the buffer is full then we append ".\n" to the end of it, return immediately and ignore the rest
// of the data we are asked to print until we get a new line.
void Line::Write(char b, bool block)
{
	if (b == '\n')
	{
		outputColumn = 0;
	}
	else
	{
		++outputColumn;
	}

	if (block)
	{
		// We failed to print an unimportant message that (unusually) didn't finish in a newline
		ignoringOutputLine = false;
	}

	if (ignoringOutputLine)
	{
		// We have already failed to write some characters of this message line, so don't write any of it.
		// But try to start sending again after this line finishes.
		if (b == '\n')
		{
			ignoringOutputLine = false;
		}
		TryFlushOutput();		// this may help free things up
	}
	else
	{
		for(;;)
		{
			TryFlushOutput();
			if (block)
			{
				SerialUSB.flush();
			}

			if (outputNumChars == 0 && SerialUSB.canWrite() != 0)
			{
				// We can write the character directly into the USB output buffer
				++inUsbWrite;
				SerialUSB.write(b);
				--inUsbWrite;
				break;
			}
			else if (   outputNumChars + 2 < lineOutBufSize							// save 2 spaces in the output buffer
					 || (outputNumChars < lineOutBufSize && (block || b == '\n'))	//...unless doing blocking output or writing newline
					)
			{
				outBuffer[(outputGetIndex + outputNumChars) % lineOutBufSize] = b;
				++outputNumChars;
				break;
			}
			else if (!block)
			{
				if (outputNumChars + 2 == lineOutBufSize)
				{
					// We still have our 2 free characters, so append ".\n" to the line to indicate it was incomplete
					outBuffer[(outputGetIndex + outputNumChars) % lineOutBufSize] = '.';
					++outputNumChars;
					outBuffer[(outputGetIndex + outputNumChars) % lineOutBufSize] = '\n';
					++outputNumChars;
				}
				else
				{
					// As we don't have 2 spare characters in the buffer, we can't have written any of the current line.
					// So ignore the whole line.
				}
				ignoringOutputLine = true;
				break;
			}
		}

		TryFlushOutput();
		if (block)
		{
			SerialUSB.flush();
		}
	}
	// else discard the character
}

void Line::Write(const char* b, bool block)
{
	while (*b)
	{
		Write(*b++, block);
	}
}

void Line::TryFlushOutput()
{
	//debug
	//while (SerialUSB.canWrite() == 0) {}
	//end debug

	while (outputNumChars != 0 && SerialUSB.canWrite() != 0)
	{
		++inUsbWrite;
		SerialUSB.write(outBuffer[outputGetIndex]);
		--inUsbWrite;
		outputGetIndex = (outputGetIndex + 1) % lineOutBufSize;
		--outputNumChars;
	}
}

// End