},\r
};\r
\r
-const uint8_t SineTable[] PROGMEM =\r
+/** 8-bit 256 entry Sine Wave lookup table */\r
+const uint8_t SineTable[256] =\r
{\r
- 0x80, 0x83, 0x86, 0x89, 0x8c, 0x8f, 0x92, 0x95, 0x98, 0x9c, 0x9f, 0xa2, 0xa5, 0xa8, 0xab, 0xae, \r
- 0xb0, 0xb3, 0xb6, 0xb9, 0xbc, 0xbf, 0xc1, 0xc4, 0xc7, 0xc9, 0xcc, 0xce, 0xd1, 0xd3, 0xd5, 0xd8, \r
- 0xda, 0xdc, 0xde, 0xe0, 0xe2, 0xe4, 0xe6, 0xe8, 0xea, 0xec, 0xed, 0xef, 0xf0, 0xf2, 0xf3, 0xf5, \r
- 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfc, 0xfd, 0xfe, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, \r
- 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xfe, 0xfd, 0xfc, 0xfc, 0xfb, 0xfa, 0xf9, 0xf8, 0xf7, \r
- 0xf6, 0xf5, 0xf3, 0xf2, 0xf0, 0xef, 0xed, 0xec, 0xea, 0xe8, 0xe6, 0xe4, 0xe2, 0xe0, 0xde, 0xdc, \r
- 0xda, 0xd8, 0xd5, 0xd3, 0xd1, 0xce, 0xcc, 0xc9, 0xc7, 0xc4, 0xc1, 0xbf, 0xbc, 0xb9, 0xb6, 0xb3, \r
- 0xb0, 0xae, 0xab, 0xa8, 0xa5, 0xa2, 0x9f, 0x9c, 0x98, 0x95, 0x92, 0x8f, 0x8c, 0x89, 0x86, 0x83, \r
- 0x80, 0x7c, 0x79, 0x76, 0x73, 0x70, 0x6d, 0x6a, 0x67, 0x63, 0x60, 0x5d, 0x5a, 0x57, 0x54, 0x51, \r
- 0x4f, 0x4c, 0x49, 0x46, 0x43, 0x40, 0x3e, 0x3b, 0x38, 0x36, 0x33, 0x31, 0x2e, 0x2c, 0x2a, 0x27, \r
- 0x25, 0x23, 0x21, 0x1f, 0x1d, 0x1b, 0x19, 0x17, 0x15, 0x13, 0x12, 0x10, 0x0f, 0x0d, 0x0c, 0x0a, \r
- 0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x03, 0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, \r
- 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, \r
- 0x09, 0x0a, 0x0c, 0x0d, 0x0f, 0x10, 0x12, 0x13, 0x15, 0x17, 0x19, 0x1b, 0x1d, 0x1f, 0x21, 0x23, \r
- 0x25, 0x27, 0x2a, 0x2c, 0x2e, 0x31, 0x33, 0x36, 0x38, 0x3b, 0x3e, 0x40, 0x43, 0x46, 0x49, 0x4c, \r
- 0x4f, 0x51, 0x54, 0x57, 0x5a, 0x5d, 0x60, 0x63, 0x67, 0x6a, 0x6d, 0x70, 0x73, 0x76, 0x79, 0x7c\r
+ 128, 131, 134, 137, 140, 143, 146, 149, 152, 156, 159, 162, 165, 168, 171, 174,\r
+ 176, 179, 182, 185, 188, 191, 193, 196, 199, 201, 204, 206, 209, 211, 213, 216,\r
+ 218, 220, 222, 224, 226, 228, 230, 232, 234, 236, 237, 239, 240, 242, 243, 245,\r
+ 246, 247, 248, 249, 250, 251, 252, 252, 253, 254, 254, 255, 255, 255, 255, 255,\r
+ 255, 255, 255, 255, 255, 255, 254, 254, 253, 252, 252, 251, 250, 249, 248, 247,\r
+ 246, 245, 243, 242, 240, 239, 237, 236, 234, 232, 230, 228, 226, 224, 222, 220,\r
+ 218, 216, 213, 211, 209, 206, 204, 201, 199, 196, 193, 191, 188, 185, 182, 179,\r
+ 176, 174, 171, 168, 165, 162, 159, 156, 152, 149, 146, 143, 140, 137, 134, 131,\r
+ 128, 124, 121, 118, 115, 112, 109, 106, 103, 99, 96, 93, 90, 87, 84, 81,\r
+ 79, 76, 73, 70, 67, 64, 62, 59, 56, 54, 51, 49, 46, 44, 42, 39,\r
+ 37, 35, 33, 31, 29, 27, 25, 23, 21, 19, 18, 16, 15, 13, 12, 10,\r
+ 9, 8, 7, 6, 5, 4, 3, 3, 2, 1, 1, 0, 0, 0, 0, 0,\r
+ 0, 0, 0, 0, 0, 0, 1, 1, 2, 3, 3, 4, 5, 6, 7, 8,\r
+ 9, 10, 12, 13, 15, 16, 18, 19, 21, 23, 25, 27, 29, 31, 33, 35,\r
+ 37, 39, 42, 44, 46, 49, 51, 54, 56, 59, 62, 64, 67, 70, 73, 76,\r
+ 79, 81, 84, 87, 90, 93, 96, 99, 103, 106, 109, 112, 115, 118, 121, 124,\r
};\r
\r
-struct\r
-{\r
- uint8_t Pitch;\r
- uint8_t Velocity;\r
- \r
- uint8_t CurrentPos;\r
- uint8_t ElapsedTicks;\r
-} ChannelStates[10];\r
+/** Array of structures describing each note being generated */\r
+DDSNoteData NoteData[MAX_SIMULTANEOUS_NOTES];\r
\r
/** Main program entry point. This routine contains the overall program flow, including initial\r
* setup of all components and the main program loop.\r
SetupHardware();\r
\r
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);\r
+ sei();\r
\r
for (;;)\r
{\r
MIDI_EventPacket_t ReceivedMIDIEvent;\r
if (MIDI_Device_ReceiveEventPacket(&Keyboard_MIDI_Interface, &ReceivedMIDIEvent))\r
{\r
- if (ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_ON >> 4))\r
+ if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_ON >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0))\r
{\r
- ChannelStates[ReceivedMIDIEvent.Data1 & 0x0F].Pitch = ReceivedMIDIEvent.Data2;\r
- ChannelStates[ReceivedMIDIEvent.Data1 & 0x0F].Velocity = ReceivedMIDIEvent.Data3;\r
-\r
+ DDSNoteData* LRUNoteStruct = &NoteData[0];\r
+ \r
+ /* Find a free entry in the note table to use for the note being turned on */\r
+ for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)\r
+ {\r
+ /* Check if the note is unused */\r
+ if (!(NoteData[i].Pitch))\r
+ {\r
+ /* If a note is unused, it's age is essentially infinite - always prefer unused not entries */\r
+ LRUNoteStruct = &NoteData[i];\r
+ break;\r
+ }\r
+ else if (NoteData[i].LRUAge > LRUNoteStruct->LRUAge)\r
+ {\r
+ /* If an older entry that the current entry has been found, prefer overwriting that one */ \r
+ LRUNoteStruct = &NoteData[i];\r
+ }\r
+ \r
+ NoteData[i].LRUAge++;\r
+ }\r
+ \r
+ /* Update the oldest note entry with the new note data and reset its age */\r
+ LRUNoteStruct->Pitch = ReceivedMIDIEvent.Data2;\r
+ LRUNoteStruct->TableIncrement = (uint32_t)(BASE_INCREMENT * SCALE_FACTOR) +\r
+ ((uint32_t)(BASE_INCREMENT * NOTE_OCTIVE_RATIO * SCALE_FACTOR) *\r
+ (ReceivedMIDIEvent.Data2 - BASE_PITCH_INDEX));\r
+ LRUNoteStruct->TablePosition = 0;\r
+ LRUNoteStruct->LRUAge = 0;\r
+\r
+ /* Turn on indicator LED to indicate note generation activity */\r
LEDs_SetAllLEDs(LEDS_LED1);\r
}\r
- else if (ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_OFF >> 4))\r
+ else if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_OFF >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0))\r
{\r
- ChannelStates[ReceivedMIDIEvent.Data1 & 0x0F].Velocity = 0;\r
- \r
- LEDs_SetAllLEDs(LEDS_NO_LEDS);\r
- }\r
- }\r
-\r
- /* Check if the sample reload timer period has elapsed, and that the USB bus is ready for a new sample */\r
- if (TIFR0 & (1 << OCF0A))\r
- {\r
- /* Clear the sample reload timer */\r
- TIFR0 |= (1 << OCF0A);\r
-\r
- uint8_t OutputSample = 0;\r
+ bool FoundActiveNote = false;\r
\r
- /* Loop through the channels (excluding percussion channel 10) and generate next sample */\r
- for (uint8_t Channel = 0; Channel < 9; Channel++)\r
- {\r
- /* Channel only contributes if it is not muted */\r
- if (ChannelStates[Channel].Velocity)\r
+ /* Find the note in the note table to turn off */\r
+ for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)\r
{\r
- /* Fetch the current sample from the sine lookup table */\r
- uint8_t TableValue = pgm_read_byte(&SineTable[ChannelStates[Channel].CurrentPos]);\r
- \r
- /* Scale sample value by the velocity of the channel */\r
- TableValue = ((uint16_t)TableValue << 6) / ChannelStates[Channel].Velocity;\r
- \r
- /* Add the sample to the output waveform */\r
- OutputSample += TableValue;\r
+ if (NoteData[i].Pitch == ReceivedMIDIEvent.Data2)\r
+ NoteData[i].Pitch = 0;\r
+ else if (NoteData[i].Pitch)\r
+ FoundActiveNote = true;\r
}\r
\r
- /* Calculate next sample table position for this channel */\r
- ChannelStates[Channel].CurrentPos += ChannelStates[Channel].Pitch;\r
+ /* If all notes off, turn off the indicator LED */\r
+ if (!(FoundActiveNote))\r
+ LEDs_SetAllLEDs(LEDS_NO_LEDS);\r
}\r
- \r
- /* Output the sample to the PWM timer */\r
- OCR3A = OutputSample;\r
}\r
\r
MIDI_Device_USBTask(&Keyboard_MIDI_Interface);\r
}\r
}\r
\r
+/** ISR to handle the reloading of the PWM timer with the next sample. */\r
+ISR(TIMER0_COMPA_vect, ISR_BLOCK)\r
+{\r
+ uint16_t MixedSample = 0;\r
+ \r
+ /* Sum together all the active notes to form a single sample */\r
+ for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)\r
+ {\r
+ if (NoteData[i].Pitch)\r
+ {\r
+ MixedSample += SineTable[NoteData[i].TablePosition >> 24];\r
+ NoteData[i].TablePosition += NoteData[i].TableIncrement;\r
+ }\r
+ }\r
+ \r
+ /* Output clamped mixed sample value to the PWM */\r
+ OCR3A = (MixedSample <= 0xFF) ? MixedSample : 0xFF;\r
+}\r
+\r
/** Configures the board hardware and chip peripherals for the demo's functionality. */\r
void SetupHardware(void)\r
{\r
USB_Init();\r
\r
/* Sample reload timer initialization */\r
- OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1;\r
+ TIMSK0 = (1 << OCIE0A);\r
+ OCR0A = (VIRTUAL_SAMPLE_TABLE_SIZE / 8);\r
TCCR0A = (1 << WGM01); // CTC mode\r
TCCR0B = (1 << CS01); // Fcpu/8 speed\r
\r
+ /* Set speaker as output */\r
+ DDRC |= (1 << 6);\r
+\r
/* PWM speaker timer initialization */\r
- TCCR3A = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0)); // Set on match, clear on TOP\r
+ TCCR3A = ((1 << WGM31) | (1 << COM3A1) | (1 << COM3A0)); // Set on match, clear on TOP\r
TCCR3B = ((1 << WGM32) | (1 << CS30)); // Fast 8-Bit PWM, Fcpu speed\r
}\r
\r
{\r
LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY);\r
\r
+ /* Disable any notes currently being played */\r
+ for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++)\r
+ NoteData[i].Pitch = 0;\r
+\r
/* Set speaker as input to reduce current draw */\r
DDRC &= ~(1 << 6);\r
}\r
/** Event handler for the library USB Configuration Changed event. */\r
void EVENT_USB_Device_ConfigurationChanged(void)\r
{\r
- LEDs_SetAllLEDs(LEDMASK_USB_READY);\r
+ bool ConfigSuccess = true;\r
+\r
+ ConfigSuccess &= MIDI_Device_ConfigureEndpoints(&Keyboard_MIDI_Interface);\r
\r
- if (!(MIDI_Device_ConfigureEndpoints(&Keyboard_MIDI_Interface)))\r
- LEDs_SetAllLEDs(LEDMASK_USB_ERROR);\r
+ LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR);\r
}\r
\r
-/** Event handler for the library USB Unhandled Control Request event. */\r
-void EVENT_USB_Device_UnhandledControlRequest(void)\r
+/** Event handler for the library USB Control Request event. */\r
+void EVENT_USB_Device_ControlRequest(void)\r
{\r
MIDI_Device_ProcessControlRequest(&Keyboard_MIDI_Interface);\r
}\r
projects / pub / USBasp.git / blobdiff