Projects/MIDIToneGenerator/MIDIToneGenerator.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2011.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2011  Dean Camera (dean [at] fourwalledcubicle [dot] com)
  11
  12   Permission to use, copy, modify, distribute, and sell this
  13   software and its documentation for any purpose is hereby granted
  14   without fee, provided that the above copyright notice appear in
  15   all copies and that both that the copyright notice and this
  16   permission notice and warranty disclaimer appear in supporting
  17   documentation, and that the name of the author not be used in
  18   advertising or publicity pertaining to distribution of the
  19   software without specific, written prior permission.
  20
  21   The author disclaim all warranties with regard to this
  22   software, including all implied warranties of merchantability
  23   and fitness.  In no event shall the author be liable for any
  24   special, indirect or consequential damages or any damages
  25   whatsoever resulting from loss of use, data or profits, whether
  26   in an action of contract, negligence or other tortious action,
  27   arising out of or in connection with the use or performance of
  28   this software.
  29 */
  30
  31 /** \file
  32  *
  33  *  Main source file for the MIDI demo. This file contains the main tasks of
  34  *  the demo and is responsible for the initial application hardware configuration.
  35  */
  36
  37 #include "MIDIToneGenerator.h"
  38
  39 /** LUFA MIDI Class driver interface configuration and state information. This structure is
  40  *  passed to all MIDI Class driver functions, so that multiple instances of the same class
  41  *  within a device can be differentiated from one another.
  42  */
  43 USB_ClassInfo_MIDI_Device_t Keyboard_MIDI_Interface =
  44         {
  45                 .Config =
  46                         {
  47                                 .StreamingInterfaceNumber = 1,
  48
  49                                 .DataINEndpointNumber      = MIDI_STREAM_IN_EPNUM,
  50                                 .DataINEndpointSize        = MIDI_STREAM_EPSIZE,
  51                                 .DataINEndpointDoubleBank  = false,
  52
  53                                 .DataOUTEndpointNumber     = MIDI_STREAM_OUT_EPNUM,
  54                                 .DataOUTEndpointSize       = MIDI_STREAM_EPSIZE,
  55                                 .DataOUTEndpointDoubleBank = false,
  56                         },
  57         };
  58
  59 /** 8-bit 256 entry Sine Wave lookup table */
  60 const uint8_t SineTable[256] =
  61 {
  62         128, 131, 134, 137, 140, 143, 146, 149, 152, 156, 159, 162, 165, 168, 171, 174,
  63         176, 179, 182, 185, 188, 191, 193, 196, 199, 201, 204, 206, 209, 211, 213, 216,
  64         218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 237, 239, 240, 242, 243, 245,
  65         246, 247, 248, 249, 250, 251, 252, 252, 253, 254, 254, 255, 255, 255, 255, 255,
  66         255, 255, 255, 255, 255, 255, 254, 254, 253, 252, 252, 251, 250, 249, 248, 247,
  67         246, 245, 243, 242, 240, 239, 237, 236, 234, 232, 230, 228, 226, 224, 222, 220,
  68         218, 216, 213, 211, 209, 206, 204, 201, 199, 196, 193, 191, 188, 185, 182, 179,
  69         176, 174, 171, 168, 165, 162, 159, 156, 152, 149, 146, 143, 140, 137, 134, 131,
  70         128, 124, 121, 118, 115, 112, 109, 106, 103,  99,  96,  93,  90,  87,  84,  81,
  71          79,  76,  73,  70,  67,  64,  62,  59,  56,  54,  51,  49,  46,  44,  42,  39,
  72          37,  35,  33,  31,  29,  27,  25,  23,  21,  19,  18,  16,  15,  13,  12,  10,
  73           9,   8,   7,   6,   5,   4,   3,   3,   2,   1,   1,   0,   0,   0,   0,   0,
  74           0,   0,   0,   0,   0,   0,   1,   1,   2,   3,   3,   4,   5,   6,   7,   8,
  75           9,  10,  12,  13,  15,  16,  18,  19,  21,  23,  25,  27,  29,  31,  33,  35,
  76          37,  39,  42,  44,  46,  49,  51,  54,  56,  59,  62,  64,  67,  70,  73,  76,
  77          79,  81,  84,  87,  90,  93,  96,  99, 103, 106, 109, 112, 115, 118, 121, 124,
  78 };
  79
  80 /** Array of structures describing each note being generated */
  81 DDSNoteData NoteData[MAX_SIMULTANEOUS_NOTES];
  82
  83 /** Main program entry point. This routine contains the overall program flow, including initial
  84  *  setup of all components and the main program loop.
  85  */
  86 int main(void)
  87 {
  88         SetupHardware();
  89
  90         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
  91         sei();
  92
  93         for (;;)
  94         {
  95                 MIDI_EventPacket_t ReceivedMIDIEvent;
  96                 if (MIDI_Device_ReceiveEventPacket(&Keyboard_MIDI_Interface, &ReceivedMIDIEvent))
  97                 {
  98                         if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_ON >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0))
  99                         {
 100                                 DDSNoteData* LRUNoteStruct = &NoteData[0];
 101
 102                                 /* Find a free entry in the note table to use for the note being turned on */
 103                                 for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
 104                                 {
 105                                         /* Check if the note is unused */
 106                                         if (!(NoteData[i].Pitch))
 107                                         {
 108                                                 /* If a note is unused, it's age is essentially infinite - always prefer unused not entries */
 109                                                 LRUNoteStruct = &NoteData[i];
 110                                                 break;
 111                                         }
 112                                         else if (NoteData[i].LRUAge >= LRUNoteStruct->LRUAge)
 113                                         {
 114                                                 /* If an older entry that the current entry has been found, prefer overwriting that one */
 115                                                 LRUNoteStruct = &NoteData[i];
 116                                         }
 117
 118                                         NoteData[i].LRUAge++;
 119                                 }
 120
 121                                 /* Update the oldest note entry with the new note data and reset its age */
 122                                 LRUNoteStruct->Pitch          = ReceivedMIDIEvent.Data2;
 123                                 LRUNoteStruct->TableIncrement = (uint32_t)(BASE_INCREMENT * SCALE_FACTOR) +
 124                                                                          ((uint32_t)(BASE_INCREMENT * NOTE_OCTIVE_RATIO * SCALE_FACTOR) *
 125                                                                           (ReceivedMIDIEvent.Data2 - BASE_PITCH_INDEX));
 126                                 LRUNoteStruct->TablePosition  = 0;
 127                                 LRUNoteStruct->LRUAge         = 0;
 128
 129                                 /* Turn on indicator LED to indicate note generation activity */
 130                                 LEDs_SetAllLEDs(LEDS_LED1);
 131                         }
 132                         else if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_OFF >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0))
 133                         {
 134                                 bool FoundActiveNote = false;
 135
 136                                 /* Find the note in the note table to turn off */
 137                                 for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
 138                                 {
 139                                         if (NoteData[i].Pitch == ReceivedMIDIEvent.Data2)
 140                                           NoteData[i].Pitch = 0;
 141                                         else if (NoteData[i].Pitch)
 142                                           FoundActiveNote   = true;
 143                                 }
 144
 145                                 /* If all notes off, turn off the indicator LED */
 146                                 if (!(FoundActiveNote))
 147                                   LEDs_SetAllLEDs(LEDS_NO_LEDS);
 148                         }
 149                 }
 150
 151                 MIDI_Device_USBTask(&Keyboard_MIDI_Interface);
 152                 USB_USBTask();
 153         }
 154 }
 155
 156 /** ISR to handle the reloading of the PWM timer with the next sample. */
 157 ISR(TIMER0_COMPA_vect, ISR_BLOCK)
 158 {
 159         uint16_t MixedSample = 0;
 160
 161         /* Sum together all the active notes to form a single sample */
 162         for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
 163         {
 164                 /* A non-zero pitch indicates the note is active */
 165                 if (NoteData[i].Pitch)
 166                 {
 167                         /* Use the top 8 bits of the table position as the sample table index */
 168                         uint8_t TableIndex = ((uint8_t*)&NoteData[i].TablePosition)[3];
 169
 170                         /* Add the new tone sample to the accumulator and increment the table position */
 171                         MixedSample += SineTable[TableIndex];
 172                         NoteData[i].TablePosition += NoteData[i].TableIncrement;
 173                 }
 174         }
 175
 176         /* Output clamped mixed sample value to the PWM */
 177         OCR3A = (MixedSample <= 0xFF) ? MixedSample : 0xFF;
 178 }
 179
 180 /** Configures the board hardware and chip peripherals for the demo's functionality. */
 181 void SetupHardware(void)
 182 {
 183         /* Disable watchdog if enabled by bootloader/fuses */
 184         MCUSR &= ~(1 << WDRF);
 185         wdt_disable();
 186
 187         /* Disable clock division */
 188         clock_prescale_set(clock_div_1);
 189
 190         /* Hardware Initialization */
 191         LEDs_Init();
 192         USB_Init();
 193
 194         /* Sample reload timer initialization */
 195         TIMSK0  = (1 << OCIE0A);
 196         OCR0A   = (VIRTUAL_SAMPLE_TABLE_SIZE / 8);
 197         TCCR0A  = (1 << WGM01);  // CTC mode
 198         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 199
 200         /* Set speaker as output */
 201         DDRC |= (1 << 6);
 202
 203         /* PWM speaker timer initialization */
 204         TCCR3A  = ((1 << WGM31) | (1 << COM3A1) | (1 << COM3A0)); // Set on match, clear on TOP
 205         TCCR3B  = ((1 << WGM32) | (1 << CS30));  // Fast 8-Bit PWM, Fcpu speed
 206 }
 207
 208 /** Event handler for the library USB Connection event. */
 209 void EVENT_USB_Device_Connect(void)
 210 {
 211         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 212
 213         /* Set speaker as output */
 214         DDRC |= (1 << 6);
 215 }
 216
 217 /** Event handler for the library USB Disconnection event. */
 218 void EVENT_USB_Device_Disconnect(void)
 219 {
 220         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 221
 222         /* Disable any notes currently being played */
 223         for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
 224           NoteData[i].Pitch = 0;
 225
 226         /* Set speaker as input to reduce current draw */
 227         DDRC &= ~(1 << 6);
 228 }
 229
 230 /** Event handler for the library USB Configuration Changed event. */
 231 void EVENT_USB_Device_ConfigurationChanged(void)
 232 {
 233         bool ConfigSuccess = true;
 234
 235         ConfigSuccess &= MIDI_Device_ConfigureEndpoints(&Keyboard_MIDI_Interface);
 236
 237         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 238 }
 239
 240 /** Event handler for the library USB Control Request event. */
 241 void EVENT_USB_Device_ControlRequest(void)
 242 {
 243         MIDI_Device_ProcessControlRequest(&Keyboard_MIDI_Interface);
 244 }