Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c

   1 /*
   2              LUFA Library
   3      Copyright (C) Dean Camera, 2010.
   4
   5   dean [at] fourwalledcubicle [dot] com
   6       www.fourwalledcubicle.com
   7 */
   8
   9 /*
  10   Copyright 2010  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                 if (NoteData[i].Pitch)
 165                 {
 166                         MixedSample += SineTable[NoteData[i].TablePosition >> 24];
 167                         NoteData[i].TablePosition += NoteData[i].TableIncrement;
 168                 }
 169         }
 170
 171         /* Output clamped mixed sample value to the PWM */
 172         OCR3A = (MixedSample <= 0xFF) ? MixedSample : 0xFF;
 173 }
 174
 175 /** Configures the board hardware and chip peripherals for the demo's functionality. */
 176 void SetupHardware(void)
 177 {
 178         /* Disable watchdog if enabled by bootloader/fuses */
 179         MCUSR &= ~(1 << WDRF);
 180         wdt_disable();
 181
 182         /* Disable clock division */
 183         clock_prescale_set(clock_div_1);
 184
 185         /* Hardware Initialization */
 186         LEDs_Init();
 187         USB_Init();
 188
 189         /* Sample reload timer initialization */
 190         TIMSK0  = (1 << OCIE0A);
 191         OCR0A   = (VIRTUAL_SAMPLE_TABLE_SIZE / 8);
 192         TCCR0A  = (1 << WGM01);  // CTC mode
 193         TCCR0B  = (1 << CS01);   // Fcpu/8 speed
 194
 195         /* Set speaker as output */
 196         DDRC |= (1 << 6);
 197
 198         /* PWM speaker timer initialization */
 199         TCCR3A  = ((1 << WGM31) | (1 << COM3A1) | (1 << COM3A0)); // Set on match, clear on TOP
 200         TCCR3B  = ((1 << WGM32) | (1 << CS30));  // Fast 8-Bit PWM, Fcpu speed
 201 }
 202
 203 /** Event handler for the library USB Connection event. */
 204 void EVENT_USB_Device_Connect(void)
 205 {
 206         LEDs_SetAllLEDs(LEDMASK_USB_ENUMERATING);
 207
 208         /* Set speaker as output */
 209         DDRC |= (1 << 6);
 210 }
 211
 212 /** Event handler for the library USB Disconnection event. */
 213 void EVENT_USB_Device_Disconnect(void)
 214 {
 215         LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);
 216
 217         /* Disable any notes currently being played */
 218         for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)
 219           NoteData[i].Pitch = 0;
 220
 221         /* Set speaker as input to reduce current draw */
 222         DDRC &= ~(1 << 6);
 223 }
 224
 225 /** Event handler for the library USB Configuration Changed event. */
 226 void EVENT_USB_Device_ConfigurationChanged(void)
 227 {
 228         bool ConfigSuccess = true;
 229
 230         ConfigSuccess &= MIDI_Device_ConfigureEndpoints(&Keyboard_MIDI_Interface);
 231
 232         LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);
 233 }
 234
 235 /** Event handler for the library USB Control Request event. */
 236 void EVENT_USB_Device_ControlRequest(void)
 237 {
 238         MIDI_Device_ProcessControlRequest(&Keyboard_MIDI_Interface);
 239 }