X-Git-Url: http://git.linex4red.de/pub/USBasp.git/blobdiff_plain/c58c53dba90fdc19d38f5e5d6957f2ede2a740f3..c879887dce0506c6ae25490ed7d42a7c7eec7337:/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c diff --git a/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c b/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c index 8d5cd05c9..c8e06bed4 100644 --- a/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c +++ b/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c @@ -56,34 +56,29 @@ USB_ClassInfo_MIDI_Device_t Keyboard_MIDI_Interface = }, }; -const uint8_t SineTable[] PROGMEM = +/** 8-bit 256 entry Sine Wave lookup table */ +const uint8_t SineTable[256] = { - 0x80, 0x83, 0x86, 0x89, 0x8c, 0x8f, 0x92, 0x95, 0x98, 0x9c, 0x9f, 0xa2, 0xa5, 0xa8, 0xab, 0xae, - 0xb0, 0xb3, 0xb6, 0xb9, 0xbc, 0xbf, 0xc1, 0xc4, 0xc7, 0xc9, 0xcc, 0xce, 0xd1, 0xd3, 0xd5, 0xd8, - 0xda, 0xdc, 0xde, 0xe0, 0xe2, 0xe4, 0xe6, 0xe8, 0xea, 0xec, 0xed, 0xef, 0xf0, 0xf2, 0xf3, 0xf5, - 0xf6, 0xf7, 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfc, 0xfd, 0xfe, 0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, - 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe, 0xfe, 0xfd, 0xfc, 0xfc, 0xfb, 0xfa, 0xf9, 0xf8, 0xf7, - 0xf6, 0xf5, 0xf3, 0xf2, 0xf0, 0xef, 0xed, 0xec, 0xea, 0xe8, 0xe6, 0xe4, 0xe2, 0xe0, 0xde, 0xdc, - 0xda, 0xd8, 0xd5, 0xd3, 0xd1, 0xce, 0xcc, 0xc9, 0xc7, 0xc4, 0xc1, 0xbf, 0xbc, 0xb9, 0xb6, 0xb3, - 0xb0, 0xae, 0xab, 0xa8, 0xa5, 0xa2, 0x9f, 0x9c, 0x98, 0x95, 0x92, 0x8f, 0x8c, 0x89, 0x86, 0x83, - 0x80, 0x7c, 0x79, 0x76, 0x73, 0x70, 0x6d, 0x6a, 0x67, 0x63, 0x60, 0x5d, 0x5a, 0x57, 0x54, 0x51, - 0x4f, 0x4c, 0x49, 0x46, 0x43, 0x40, 0x3e, 0x3b, 0x38, 0x36, 0x33, 0x31, 0x2e, 0x2c, 0x2a, 0x27, - 0x25, 0x23, 0x21, 0x1f, 0x1d, 0x1b, 0x19, 0x17, 0x15, 0x13, 0x12, 0x10, 0x0f, 0x0d, 0x0c, 0x0a, - 0x09, 0x08, 0x07, 0x06, 0x05, 0x04, 0x03, 0x03, 0x02, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, - 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01, 0x02, 0x03, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, - 0x09, 0x0a, 0x0c, 0x0d, 0x0f, 0x10, 0x12, 0x13, 0x15, 0x17, 0x19, 0x1b, 0x1d, 0x1f, 0x21, 0x23, - 0x25, 0x27, 0x2a, 0x2c, 0x2e, 0x31, 0x33, 0x36, 0x38, 0x3b, 0x3e, 0x40, 0x43, 0x46, 0x49, 0x4c, - 0x4f, 0x51, 0x54, 0x57, 0x5a, 0x5d, 0x60, 0x63, 0x67, 0x6a, 0x6d, 0x70, 0x73, 0x76, 0x79, 0x7c + 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, }; -struct -{ - uint8_t Pitch; - uint8_t Velocity; - - uint8_t CurrentPos; - uint8_t ElapsedTicks; -} ChannelStates[10]; +/** Array of structures describing each note being generated */ +DDSNoteData NoteData[MAX_SIMULTANEOUS_NOTES]; /** Main program entry point. This routine contains the overall program flow, including initial * setup of all components and the main program loop. @@ -93,57 +88,64 @@ 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)) + if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_ON >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0)) { - ChannelStates[ReceivedMIDIEvent.Data1 & 0x0F].Pitch = ReceivedMIDIEvent.Data2; - ChannelStates[ReceivedMIDIEvent.Data1 & 0x0F].Velocity = ReceivedMIDIEvent.Data3; - + DDSNoteData* LRUNoteStruct = &NoteData[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++) + { + /* Check if the note is unused */ + if (!(NoteData[i].Pitch)) + { + /* If a note is unused, it's age is essentially infinite - always prefer unused not entries */ + LRUNoteStruct = &NoteData[i]; + break; + } + else if (NoteData[i].LRUAge > LRUNoteStruct->LRUAge) + { + /* If an older entry that the current entry has been found, prefer overwriting that one */ + LRUNoteStruct = &NoteData[i]; + } + + NoteData[i].LRUAge++; + } + + /* Update the oldest note entry with the new note data and reset its age */ + LRUNoteStruct->Pitch = ReceivedMIDIEvent.Data2; + LRUNoteStruct->TableIncrement = (uint32_t)(BASE_INCREMENT * SCALE_FACTOR) + + ((uint32_t)(BASE_INCREMENT * NOTE_OCTIVE_RATIO * SCALE_FACTOR) * + (ReceivedMIDIEvent.Data2 - BASE_PITCH_INDEX)); + LRUNoteStruct->TablePosition = 0; + LRUNoteStruct->LRUAge = 0; + + /* Turn on indicator LED to indicate note generation activity */ LEDs_SetAllLEDs(LEDS_LED1); } - else if (ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_OFF >> 4)) + else if ((ReceivedMIDIEvent.Command == (MIDI_COMMAND_NOTE_OFF >> 4)) && ((ReceivedMIDIEvent.Data1 & 0x0F) == 0)) { - ChannelStates[ReceivedMIDIEvent.Data1 & 0x0F].Velocity = 0; - - LEDs_SetAllLEDs(LEDS_NO_LEDS); - } - } - - /* Check if the sample reload timer period has elapsed, and that the USB bus is ready for a new sample */ - if (TIFR0 & (1 << OCF0A)) - { - /* Clear the sample reload timer */ - TIFR0 |= (1 << OCF0A); - - uint8_t OutputSample = 0; + bool FoundActiveNote = false; - /* Loop through the channels (excluding percussion channel 10) and generate next sample */ - for (uint8_t Channel = 0; Channel < 9; Channel++) - { - /* Channel only contributes if it is not muted */ - if (ChannelStates[Channel].Velocity) + /* Find the note in the note table to turn off */ + for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++) { - /* Fetch the current sample from the sine lookup table */ - uint8_t TableValue = pgm_read_byte(&SineTable[ChannelStates[Channel].CurrentPos]); - - /* Scale sample value by the velocity of the channel */ - TableValue = ((uint16_t)TableValue << 6) / ChannelStates[Channel].Velocity; - - /* Add the sample to the output waveform */ - OutputSample += TableValue; + if (NoteData[i].Pitch == ReceivedMIDIEvent.Data2) + NoteData[i].Pitch = 0; + else if (NoteData[i].Pitch) + FoundActiveNote = true; } - /* Calculate next sample table position for this channel */ - ChannelStates[Channel].CurrentPos += ChannelStates[Channel].Pitch; + /* If all notes off, turn off the indicator LED */ + if (!(FoundActiveNote)) + LEDs_SetAllLEDs(LEDS_NO_LEDS); } - - /* Output the sample to the PWM timer */ - OCR3A = OutputSample; } MIDI_Device_USBTask(&Keyboard_MIDI_Interface); @@ -151,6 +153,25 @@ int main(void) } } +/** 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) { @@ -166,12 +187,16 @@ void SetupHardware(void) USB_Init(); /* Sample reload timer initialization */ - OCR0A = (F_CPU / 8 / AUDIO_SAMPLE_FREQUENCY) - 1; + TIMSK0 = (1 << OCIE0A); + OCR0A = (VIRTUAL_SAMPLE_TABLE_SIZE / 8); TCCR0A = (1 << WGM01); // CTC mode TCCR0B = (1 << CS01); // Fcpu/8 speed + /* Set speaker as output */ + DDRC |= (1 << 6); + /* PWM speaker timer initialization */ - TCCR3A = ((1 << WGM30) | (1 << COM3A1) | (1 << COM3A0)); // Set on match, clear on TOP + TCCR3A = ((1 << WGM31) | (1 << COM3A1) | (1 << COM3A0)); // Set on match, clear on TOP TCCR3B = ((1 << WGM32) | (1 << CS30)); // Fast 8-Bit PWM, Fcpu speed } @@ -189,6 +214,10 @@ void EVENT_USB_Device_Disconnect(void) { LEDs_SetAllLEDs(LEDMASK_USB_NOTREADY); + /* Disable any notes currently being played */ + for (uint8_t i = 0; i < MAX_SIMULTANEOUS_NOTES; i++) + NoteData[i].Pitch = 0; + /* Set speaker as input to reduce current draw */ DDRC &= ~(1 << 6); } @@ -196,14 +225,15 @@ void EVENT_USB_Device_Disconnect(void) /** Event handler for the library USB Configuration Changed event. */ void EVENT_USB_Device_ConfigurationChanged(void) { - LEDs_SetAllLEDs(LEDMASK_USB_READY); + bool ConfigSuccess = true; + + ConfigSuccess &= MIDI_Device_ConfigureEndpoints(&Keyboard_MIDI_Interface); - if (!(MIDI_Device_ConfigureEndpoints(&Keyboard_MIDI_Interface))) - LEDs_SetAllLEDs(LEDMASK_USB_ERROR); + LEDs_SetAllLEDs(ConfigSuccess ? LEDMASK_USB_READY : LEDMASK_USB_ERROR); } -/** Event handler for the library USB Unhandled Control Request event. */ -void EVENT_USB_Device_UnhandledControlRequest(void) +/** Event handler for the library USB Control Request event. */ +void EVENT_USB_Device_ControlRequest(void) { MIDI_Device_ProcessControlRequest(&Keyboard_MIDI_Interface); }