Readd incomplete MIDIToneGenerator project, which can now correctly generate...

Readd incomplete MIDIToneGenerator project, which can now correctly generate up to three simultaneous notes from MIDI channel 0.

Bootloaders/CDC/BootloaderCDC.c

@@ -319,7 +319,7 @@ static void WriteNextResponseByte(const uint8_t Response)
 		}
 	}
 
-	/* Write the next byte to the OUT endpoint */
+	/* Write the next byte to the IN endpoint */
 	Endpoint_Write_Byte(Response);
 }
 

Projects/Incomplete/MIDIToneGenerator/Descriptors.c

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2010.
+
+  dean [at] fourwalledcubicle [dot] com
+           www.lufa-lib.org
+*/
+
+/*
+  Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, distribute, and sell this
+  software and its documentation for any purpose is hereby granted
+  without fee, provided that the above copyright notice appear in
+  all copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  USB Device Descriptors, for library use when in USB device mode. Descriptors are special
+ *  computer-readable structures which the host requests upon device enumeration, to determine
+ *  the device's capabilities and functions.
+ */
+
+#include "Descriptors.h"
+
+/** Device descriptor structure. This descriptor, located in FLASH memory, describes the overall
+ *  device characteristics, including the supported USB version, control endpoint size and the
+ *  number of device configurations. The descriptor is read out by the USB host when the enumeration
+ *  process begins.
+ */
+USB_Descriptor_Device_t PROGMEM DeviceDescriptor =
+{
+	.Header                 = {.Size = sizeof(USB_Descriptor_Device_t), .Type = DTYPE_Device},
+
+	.USBSpecification       = VERSION_BCD(01.10),
+	.Class                  = USB_CSCP_NoDeviceClass,
+	.SubClass               = USB_CSCP_NoDeviceSubclass,
+	.Protocol               = USB_CSCP_NoDeviceProtocol,
+
+	.Endpoint0Size          = FIXED_CONTROL_ENDPOINT_SIZE,
+
+	.VendorID               = 0x03EB,
+	.ProductID              = 0x2048,
+	.ReleaseNumber          = VERSION_BCD(00.01),
+
+	.ManufacturerStrIndex   = 0x01,
+	.ProductStrIndex        = 0x02,
+	.SerialNumStrIndex      = NO_DESCRIPTOR,
+
+	.NumberOfConfigurations = FIXED_NUM_CONFIGURATIONS
+};
+
+/** Configuration descriptor structure. This descriptor, located in FLASH memory, describes the usage
+ *  of the device in one of its supported configurations, including information about any device interfaces
+ *  and endpoints. The descriptor is read out by the USB host during the enumeration process when selecting
+ *  a configuration so that the host may correctly communicate with the USB device.
+ */
+USB_Descriptor_Configuration_t PROGMEM ConfigurationDescriptor =
+{
+	.Config =
+		{
+			.Header                   = {.Size = sizeof(USB_Descriptor_Configuration_Header_t), .Type = DTYPE_Configuration},
+
+			.TotalConfigurationSize   = sizeof(USB_Descriptor_Configuration_t),
+			.TotalInterfaces          = 2,
+
+			.ConfigurationNumber      = 1,
+			.ConfigurationStrIndex    = NO_DESCRIPTOR,
+
+			.ConfigAttributes         = (USB_CONFIG_ATTR_BUSPOWERED | USB_CONFIG_ATTR_SELFPOWERED),
+
+			.MaxPowerConsumption      = USB_CONFIG_POWER_MA(100)
+		},
+
+	.Audio_ControlInterface =
+		{
+			.Header                   = {.Size = sizeof(USB_Descriptor_Interface_t), .Type = DTYPE_Interface},
+
+			.InterfaceNumber          = 0,
+			.AlternateSetting         = 0,
+
+			.TotalEndpoints           = 0,
+
+			.Class                    = AUDIO_CSCP_AudioClass,
+			.SubClass                 = AUDIO_CSCP_ControlSubclass,
+			.Protocol                 = AUDIO_CSCP_ControlProtocol,
+
+			.InterfaceStrIndex        = NO_DESCRIPTOR
+		},
+
+	.Audio_ControlInterface_SPC =
+		{
+			.Header                   = {.Size = sizeof(USB_Audio_Descriptor_Interface_AC_t), .Type = DTYPE_CSInterface},
+			.Subtype                  = AUDIO_DSUBTYPE_CSInterface_Header,
+
+			.ACSpecification          = VERSION_BCD(01.00),
+			.TotalLength              = sizeof(USB_Audio_Descriptor_Interface_AC_t),
+
+			.InCollection             = 1,
+			.InterfaceNumber          = 1,
+		},
+
+	.Audio_StreamInterface =
+		{
+			.Header                   = {.Size = sizeof(USB_Descriptor_Interface_t), .Type = DTYPE_Interface},
+
+			.InterfaceNumber          = 1,
+			.AlternateSetting         = 0,
+
+			.TotalEndpoints           = 2,
+
+			.Class                    = AUDIO_CSCP_AudioClass,
+			.SubClass                 = AUDIO_CSCP_MIDIStreamingSubclass,
+			.Protocol                 = AUDIO_CSCP_StreamingProtocol,
+
+			.InterfaceStrIndex        = NO_DESCRIPTOR
+		},
+
+	.Audio_StreamInterface_SPC =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_AudioInterface_AS_t), .Type = DTYPE_CSInterface},
+			.Subtype                  = AUDIO_DSUBTYPE_CSInterface_General,
+
+			.AudioSpecification       = VERSION_BCD(01.00),
+
+			.TotalLength              = (sizeof(USB_Descriptor_Configuration_t) -
+			                             offsetof(USB_Descriptor_Configuration_t, Audio_StreamInterface_SPC))
+		},
+
+	.MIDI_In_Jack_Emb =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_InputJack_t), .Type = DTYPE_CSInterface},
+			.Subtype                  = AUDIO_DSUBTYPE_CSInterface_InputTerminal,
+
+			.JackType                 = MIDI_JACKTYPE_Embedded,
+			.JackID                   = 0x01,
+
+			.JackStrIndex             = NO_DESCRIPTOR
+		},
+
+	.MIDI_In_Jack_Ext =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_InputJack_t), .Type = DTYPE_CSInterface},
+			.Subtype                  = AUDIO_DSUBTYPE_CSInterface_InputTerminal,
+
+			.JackType                 = MIDI_JACKTYPE_External,
+			.JackID                   = 0x02,
+
+			.JackStrIndex             = NO_DESCRIPTOR
+		},
+
+	.MIDI_Out_Jack_Emb =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_OutputJack_t), .Type = DTYPE_CSInterface},
+			.Subtype                  = AUDIO_DSUBTYPE_CSInterface_OutputTerminal,
+
+			.JackType                 = MIDI_JACKTYPE_Embedded,
+			.JackID                   = 0x03,
+
+			.NumberOfPins             = 1,
+			.SourceJackID             = {0x02},
+			.SourcePinID              = {0x01},
+
+			.JackStrIndex             = NO_DESCRIPTOR
+		},
+
+	.MIDI_Out_Jack_Ext =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_OutputJack_t), .Type = DTYPE_CSInterface},
+			.Subtype                  = AUDIO_DSUBTYPE_CSInterface_OutputTerminal,
+
+			.JackType                 = MIDI_JACKTYPE_External,
+			.JackID                   = 0x04,
+
+			.NumberOfPins             = 1,
+			.SourceJackID             = {0x01},
+			.SourcePinID              = {0x01},
+
+			.JackStrIndex             = NO_DESCRIPTOR
+		},
+
+	.MIDI_In_Jack_Endpoint =
+		{
+			.Endpoint =
+				{
+					.Header              = {.Size = sizeof(USB_Audio_Descriptor_StreamEndpoint_Std_t), .Type = DTYPE_Endpoint},
+
+					.EndpointAddress     = (ENDPOINT_DESCRIPTOR_DIR_OUT | MIDI_STREAM_OUT_EPNUM),
+					.Attributes          = (EP_TYPE_BULK | ENDPOINT_ATTR_NO_SYNC | ENDPOINT_USAGE_DATA),
+					.EndpointSize        = MIDI_STREAM_EPSIZE,
+					.PollingIntervalMS   = 0x01
+				},
+
+			.Refresh                  = 0,
+			.SyncEndpointNumber       = 0
+		},
+
+	.MIDI_In_Jack_Endpoint_SPC =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_Jack_Endpoint_t), .Type = DTYPE_CSEndpoint},
+			.Subtype                  = AUDIO_DSUBTYPE_CSEndpoint_General,
+
+			.TotalEmbeddedJacks       = 0x01,
+			.AssociatedJackID         = {0x01}
+		},
+
+	.MIDI_Out_Jack_Endpoint =
+		{
+			.Endpoint =
+				{
+					.Header              = {.Size = sizeof(USB_Audio_Descriptor_StreamEndpoint_Std_t), .Type = DTYPE_Endpoint},
+
+					.EndpointAddress     = (ENDPOINT_DESCRIPTOR_DIR_IN | MIDI_STREAM_IN_EPNUM),
+					.Attributes          = (EP_TYPE_BULK | ENDPOINT_ATTR_NO_SYNC | ENDPOINT_USAGE_DATA),
+					.EndpointSize        = MIDI_STREAM_EPSIZE,
+					.PollingIntervalMS   = 0x01
+				},
+
+			.Refresh                  = 0,
+			.SyncEndpointNumber       = 0
+		},
+
+	.MIDI_Out_Jack_Endpoint_SPC =
+		{
+			.Header                   = {.Size = sizeof(USB_MIDI_Descriptor_Jack_Endpoint_t), .Type = DTYPE_CSEndpoint},
+			.Subtype                  = AUDIO_DSUBTYPE_CSEndpoint_General,
+
+			.TotalEmbeddedJacks       = 0x01,
+			.AssociatedJackID         = {0x03}
+		}
+};
+
+/** Language descriptor structure. This descriptor, located in FLASH memory, is returned when the host requests
+ *  the string descriptor with index 0 (the first index). It is actually an array of 16-bit integers, which indicate
+ *  via the language ID table available at USB.org what languages the device supports for its string descriptors.
+ */
+USB_Descriptor_String_t PROGMEM LanguageString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(1), .Type = DTYPE_String},
+
+	.UnicodeString          = {LANGUAGE_ID_ENG}
+};
+
+/** Manufacturer descriptor string. This is a Unicode string containing the manufacturer's details in human readable
+ *  form, and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
+ *  Descriptor.
+ */
+USB_Descriptor_String_t PROGMEM ManufacturerString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(11), .Type = DTYPE_String},
+
+	.UnicodeString          = L"Dean Camera"
+};
+
+/** Product descriptor string. This is a Unicode string containing the product's details in human readable form,
+ *  and is read out upon request by the host when the appropriate string ID is requested, listed in the Device
+ *  Descriptor.
+ */
+USB_Descriptor_String_t PROGMEM ProductString =
+{
+	.Header                 = {.Size = USB_STRING_LEN(14), .Type = DTYPE_String},
+
+	.UnicodeString          = L"LUFA MIDI Demo"
+};
+
+/** This function is called by the library when in device mode, and must be overridden (see library "USB Descriptors"
+ *  documentation) by the application code so that the address and size of a requested descriptor can be given
+ *  to the USB library. When the device receives a Get Descriptor request on the control endpoint, this function
+ *  is called so that the descriptor details can be passed back and the appropriate descriptor sent back to the
+ *  USB host.
+ */
+uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue,
+                                    const uint8_t wIndex,
+                                    const void** const DescriptorAddress)
+{
+	const uint8_t  DescriptorType   = (wValue >> 8);
+	const uint8_t  DescriptorNumber = (wValue & 0xFF);
+
+	const void* Address = NULL;
+	uint16_t    Size    = NO_DESCRIPTOR;
+
+	switch (DescriptorType)
+	{
+		case DTYPE_Device:
+			Address = &DeviceDescriptor;
+			Size    = sizeof(USB_Descriptor_Device_t);
+			break;
+		case DTYPE_Configuration:
+			Address = &ConfigurationDescriptor;
+			Size    = sizeof(USB_Descriptor_Configuration_t);
+			break;
+		case DTYPE_String:
+			switch (DescriptorNumber)
+			{
+				case 0x00:
+					Address = &LanguageString;
+					Size    = pgm_read_byte(&LanguageString.Header.Size);
+					break;
+				case 0x01:
+					Address = &ManufacturerString;
+					Size    = pgm_read_byte(&ManufacturerString.Header.Size);
+					break;
+				case 0x02:
+					Address = &ProductString;
+					Size    = pgm_read_byte(&ProductString.Header.Size);
+					break;
+			}
+
+			break;
+	}
+
+	*DescriptorAddress = Address;
+	return Size;
+}
+

Projects/Incomplete/MIDIToneGenerator/Descriptors.h

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2010.
+
+  dean [at] fourwalledcubicle [dot] com
+           www.lufa-lib.org
+*/
+
+/*
+  Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, distribute, and sell this
+  software and its documentation for any purpose is hereby granted
+  without fee, provided that the above copyright notice appear in
+  all copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  Header file for Descriptors.c.
+ */
+
+#ifndef _DESCRIPTORS_H_
+#define _DESCRIPTORS_H_
+
+	/* Includes: */
+		#include <LUFA/Drivers/USB/USB.h>
+
+		#include <avr/pgmspace.h>
+
+	/* Macros: */
+		/** Endpoint number of the MIDI streaming data IN endpoint, for device-to-host data transfers. */
+		#define MIDI_STREAM_IN_EPNUM        2
+
+		/** Endpoint number of the MIDI streaming data OUT endpoint, for host-to-device data transfers. */
+		#define MIDI_STREAM_OUT_EPNUM       1
+
+		/** Endpoint size in bytes of the Audio isochronous streaming data IN and OUT endpoints. */
+		#define MIDI_STREAM_EPSIZE          64
+
+	/* Type Defines: */
+		/** Type define for the device configuration descriptor structure. This must be defined in the
+		 *  application code, as the configuration descriptor contains several sub-descriptors which
+		 *  vary between devices, and which describe the device's usage to the host.
+		 */
+		typedef struct
+		{
+			USB_Descriptor_Configuration_Header_t     Config;
+			USB_Descriptor_Interface_t                Audio_ControlInterface;
+			USB_Audio_Descriptor_Interface_AC_t       Audio_ControlInterface_SPC;
+			USB_Descriptor_Interface_t                Audio_StreamInterface;
+			USB_MIDI_Descriptor_AudioInterface_AS_t   Audio_StreamInterface_SPC;
+			USB_MIDI_Descriptor_InputJack_t           MIDI_In_Jack_Emb;
+			USB_MIDI_Descriptor_InputJack_t           MIDI_In_Jack_Ext;
+			USB_MIDI_Descriptor_OutputJack_t          MIDI_Out_Jack_Emb;
+			USB_MIDI_Descriptor_OutputJack_t          MIDI_Out_Jack_Ext;
+			USB_Audio_Descriptor_StreamEndpoint_Std_t MIDI_In_Jack_Endpoint;
+			USB_MIDI_Descriptor_Jack_Endpoint_t       MIDI_In_Jack_Endpoint_SPC;
+			USB_Audio_Descriptor_StreamEndpoint_Std_t MIDI_Out_Jack_Endpoint;
+			USB_MIDI_Descriptor_Jack_Endpoint_t       MIDI_Out_Jack_Endpoint_SPC;
+		} USB_Descriptor_Configuration_t;
+
+	/* Function Prototypes: */
+		uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue,
+		                                    const uint8_t wIndex,
+		                                    const void** const DescriptorAddress)
+		                                    ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(3);
+
+#endif
+

Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c

+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2010.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2010  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, distribute, and sell this 
+  software and its documentation for any purpose is hereby granted
+  without fee, provided that the above copyright notice appear in 
+  all copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting 
+  documentation, and that the name of the author not be used in 
+  advertising or publicity pertaining to distribution of the 
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *
+ *  Main source file for the MIDI demo. This file contains the main tasks of
+ *  the demo and is responsible for the initial application hardware configuration.
+ */
+
+#include "MIDIToneGenerator.h"
+
+/** LUFA MIDI Class driver interface configuration and state information. This structure is
+ *  passed to all MIDI Class driver functions, so that multiple instances of the same class
+ *  within a device can be differentiated from one another.
+ */
+USB_ClassInfo_MIDI_Device_t Keyboard_MIDI_Interface =
+	{
+		.Config =
+			{
+				.StreamingInterfaceNumber = 1,
+
+				.DataINEndpointNumber      = MIDI_STREAM_IN_EPNUM,
+				.DataINEndpointSize        = MIDI_STREAM_EPSIZE,
+				.DataINEndpointDoubleBank  = false,
+
+				.DataOUTEndpointNumber     = MIDI_STREAM_OUT_EPNUM,
+				.DataOUTEndpointSize       = MIDI_STREAM_EPSIZE,
+				.DataOUTEndpointDoubleBank = false,
+			},
+	};
+
+/** 8-bit 256 entry Sine Wave lookup table */
+const uint8_t SineTable[256] =
+{
+	128, 131, 134, 137, 140, 143, 146, 149, 152, 156, 159, 162, 165, 168, 171, 174,
+	176, 179, 182, 185, 188, 191, 193, 196, 199, 201, 204, 206, 209, 211, 213, 216,
+	218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 237, 239, 240, 242, 243, 245,
+	246, 247, 248, 249, 250, 251, 252, 252, 253, 254, 254, 255, 255, 255, 255, 255,
+	255, 255, 255, 255, 255, 255, 254, 254, 253, 252, 252, 251, 250, 249, 248, 247,
+	246, 245, 243, 242, 240, 239, 237, 236, 234, 232, 230, 228, 226, 224, 222, 220,
+	218, 216, 213, 211, 209, 206, 204, 201, 199, 196, 193, 191, 188, 185, 182, 179,
+	176, 174, 171, 168, 165, 162, 159, 156, 152, 149, 146, 143, 140, 137, 134, 131,
+	128, 124, 121, 118, 115, 112, 109, 106, 103,  99,  96,  93,  90,  87,  84,  81,
+	 79,  76,  73,  70,  67,  64,  62,  59,  56,  54,  51,  49,  46,  44,  42,  39,
+	 37,  35,  33,  31,  29,  27,  25,  23,  21,  19,  18,  16,  15,  13,  12,  10,
+	  9,   8,   7,   6,   5,   4,   3,   3,   2,   1,   1,   0,   0,   0,   0,   0,
+	  0,   0,   0,   0,   0,   0,   1,   1,   2,   3,   3,   4,   5,   6,   7,   8,
+	  9,  10,  12,  13,  15,  16,  18,  19,  21,  23,  25,  27,  29,  31,  33,  35,
+	 37,  39,  42,  44,  46,  49,  51,  54,  56,  59,  62,  64,  67,  70,  73,  76,
+	 79,  81,  84,  87,  90,  93,  96,  99, 103, 106, 109, 112, 115, 118, 121, 124,
+};
+
+/** Array of structures describing each note being generated */
+struct
+{
+	uint8_t  Pitch;
+	uint32_t TableIncrement;
+	uint32_t TablePosition;
+} NoteData[3];
+
+uint8_t PhaseCounter;
+
+/** Main program entry point. This routine contains the overall program flow, including initial
+ *  setup of all components and the main program loop.
+ */
+int main(void)
+{
+	SetupHardware();
+
+	LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
+	sei();
+	
+	for (;;)
+	{
+		MIDI_EventPacket_t ReceivedMIDIEvent;
+		if (MIDI_Device_ReceiveEventPacket(&Keyboard_MIDI_Interface, &ReceivedMIDIEvent))
+		{
+			if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_ON >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0))
+			{
+				/* Find a free entry in the note table to use for the note being turned on */
+				for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
+				{
+					if (!(NoteData[i].Pitch))
+					{
+						NoteData[i].Pitch          = ReceivedMIDIEvent.Data2;
+						NoteData[i].TableIncrement = (uint32_t)(BASE_INCREMENT * SCALE_FACTOR) +
+						                             ((uint32_t)(BASE_INCREMENT * NOTE_OCTIVE_RATIO * SCALE_FACTOR) *
+						                              (ReceivedMIDIEvent.Data2 - BASE_PITCH_INDEX));
+						NoteData[i].TablePosition  = 0;
+						break;
+					}
+				}
+
+				/* Turn on indicator LED to indicate note generation activity */
+				LEDs_SetAllLEDs(LEDS_LED1);
+			}
+			else if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_OFF >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0))
+			{
+				bool FoundActiveNote = false;
+			
+				/* Find the note in the note table to turn off */
+				for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
+				{
+					if (NoteData[i].Pitch == ReceivedMIDIEvent.Data2)
+					{
+						NoteData[i].Pitch = 0;
+						FoundActiveNote      = true;
+						break;
+					}
+				}
+				
+				/* If all notes off, turn off the indicator LED */
+				if (!(FoundActiveNote))
+				  LEDs_SetAllLEDs(LEDS_NO_LEDS);
+			}
+		}
+	
+		MIDI_Device_USBTask(&Keyboard_MIDI_Interface);
+		USB_USBTask();
+	}
+}
+
+/** ISR to handle the reloading of the PWM timer with the next sample. */
+ISR(TIMER0_COMPA_vect, ISR_BLOCK)
+{
+	uint16_t MixedSample = 0;
+	
+	/* Sum together all the active notes to form a single sample */
+	for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
+	{
+		if (NoteData[i].Pitch)
+		{
+			MixedSample += SineTable[NoteData[i].TablePosition >> 24];
+			NoteData[i].TablePosition += NoteData[i].TableIncrement;
+		}
+	}
+	
+	/* Output clamped mixed sample value to the PWM */
+	OCR3A = (MixedSample <= 0xFF) ? MixedSample : 0xFF;
+}
+
+/** Configures the board hardware and chip peripherals for the demo's functionality. */
+void SetupHardware(void)
+{
+	/* Disable watchdog if enabled by bootloader/fuses */
+	MCUSR &= ~(1 << WDRF);
+	wdt_disable();