Change over MIDIToneGenerator to use only a single channel (MIDI channel 1) due to...

diff --git a/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c b/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c
index 8d5cd05..4df3750 100644 (file)
--- a/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c
+++ b/Projects/Incomplete/MIDIToneGenerator/MIDIToneGenerator.c
@@ -76,14 +76,9 @@ const uint8_t SineTable[] PROGMEM =
        0x4f, 0x51, 0x54, 0x57, 0x5a, 0x5d, 0x60, 0x63, 0x67, 0x6a, 0x6d, 0x70, 0x73, 0x76, 0x79, 0x7c\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
+uint8_t Pitch;\r
+uint8_t Velocity;      \r
+uint8_t CurrentPos;\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
@@ -99,16 +94,16 @@ int main(void)
                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
+                               Pitch    = ReceivedMIDIEvent.Data2;\r
+                               Velocity = ReceivedMIDIEvent.Data3;\r
 \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
+                               Velocity = 0;\r
                                \r
                                LEDs_SetAllLEDs(LEDS_NO_LEDS);\r
                        }\r
@@ -120,30 +115,11 @@ int main(void)
                        /* Clear the sample reload timer */\r
                        TIFR0 |= (1 << OCF0A);\r
 \r
-                       uint8_t OutputSample = 0;\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
-                               {\r
-                                       /* Fetch the current sample from the sine lookup table */\r
-                                       uint8_t TableValue = pgm_read_byte(&SineTable[ChannelStates[Channel].CurrentPos]);\r
+                       /* Fetch the current sample from the sine lookup table */\r
+                       OCR3A = Velocity ? pgm_read_byte(&SineTable[CurrentPos]) : 0;\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
-                               }\r
-                               \r
-                               /* Calculate next sample table position for this channel */\r
-                               ChannelStates[Channel].CurrentPos += ChannelStates[Channel].Pitch;\r
-                       }\r
-                       \r
-                       /* Output the sample to the PWM timer */\r
-                       OCR3A = OutputSample;\r
+                       /* Calculate next sample table position for this channel */\r
+                       CurrentPos += (Pitch >> 1);\r
                }\r
        \r
                MIDI_Device_USBTask(&Keyboard_MIDI_Interface);\r