Radio Junk Box
KAMUI MIDI-CV Example
Diff: midi_parser.c
- Revision:
- 0:25a282f1141a
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/midi_parser.c Sat May 05 11:35:41 2012 +0000
@@ -0,0 +1,259 @@
+//-------------------------------------------------------------
+// KAMUI MIDI-CV Exapmle
+// file : midi_parser.c
+// Copyright (C) 2012 RJB RadioJunkBox
+// Released under the MIT License: http://mbed.org/license/mit
+//-------------------------------------------------------------
+
+#include "mbed.h"
+#include "midi_parser.h"
+
+//-------------------------------------------------------------
+// MIDI Parser
+
+void MIDI_Parser(unsigned char mididata)
+{
+ RxByte = mididata;
+
+ if(MIDI_SystemMessage()) {
+ MIDI_ChannelMessage();
+ }
+}
+
+//-------------------------------------------------------------
+// MIDI System Meassage
+
+int MIDI_SystemMessage(void)
+{
+ if(SysEx){
+ if(RxByte == MIDI_EndSysEx){
+ SysEx = FALSE;
+ }
+ }
+ else{
+ if(RxByte < 0xF8){
+ if(RxByte > 0x7F){
+ if(RxByte == MIDI_StartSysEx){
+ SysEx = TRUE;
+ }
+ else{
+ MidiCh = RxByte & 0x0F;
+ }
+ PC = 0;
+ }
+ else{
+ MByte[PC & 0x01] = RxByte;
+ }
+ return TRUE;
+ }
+ else {
+ MIDI_SystemRealtimeMessage();
+ }
+ }
+ return FALSE;
+}
+
+//-------------------------------------------------------------
+// MIDI System Realtime Message
+
+void MIDI_SystemRealtimeMessage(void)
+{
+ switch(RxByte) {
+ case MIDI_TimingClock:
+ gMIDISYNC_CLK |= 0x01;
+ break;
+ case MIDI_Start:
+ gMIDISYNC_RUN = 0x01;
+ break;
+ case MIDI_Continue:
+ gMIDISYNC_RUN = 0x01;
+ break;
+ case MIDI_Stop:
+ gMIDISYNC_RUN = 0x00;
+ break;
+ case MIDI_ActiveSensing:
+ break;
+ case MIDI_SystemReset:
+ break;
+ }
+}
+
+//-------------------------------------------------------------
+// MIDI Channel Message
+
+void MIDI_ChannelMessage(void)
+{
+ switch(PC){
+ case 0:
+ switch(RxByte & 0xF0){
+ case MIDI_NoteOff:
+ PC = 2;
+ break;
+ case MIDI_NoteOn:
+ PC = 4;
+ break;
+ case MIDI_PolykeyPressure:
+ PC = 6;
+ break;
+ case MIDI_ProgramChange:
+ PC = 8;
+ break;
+ case MIDI_ControlChange:
+ PC = 10;
+ break;
+ case MIDI_ChannelPressure:
+ PC = 12;
+ break;
+ case MIDI_PitchBend:
+ PC = 14;
+ break;
+ } break;
+
+ // Note OFF
+ case 2:
+ PC = 3;
+ break;
+ case 3:
+ PC = 2;
+ NoteOFF();
+ break;
+
+ // Note ON
+ case 4:
+ PC = 5;
+ break;
+ case 5:
+ PC = 4;
+ if( MByte[1] == 0){
+ NoteOFF();
+ }
+ else{
+ NoteON();
+ }
+ break;
+
+ // Polyphonic Key Pressure
+ case 6:
+ PC = 7;
+ break;
+ case 7:
+ PC = 6;
+ break;
+
+ // Program Change
+ case 8:
+ break;
+
+ // Control Change
+ case 10: PC = 11; break;
+ case 11:
+ switch(MByte[0]) {
+ case MIDI_CC_Moduration:
+ gModWheelBuf[MidiCh] = MByte[1] >> 2;
+ break;
+ case MIDI_CC_DataEntry:
+ break;
+ case MIDI_CC_RPN_LSB:
+ break;
+ case MIDI_CC_RPN_MSB:
+ break;
+ case MIDI_MM_AllSoundOff:
+ break;
+ case MIDI_MM_ResetAllControl:
+ break;
+ case MIDI_MM_AllNoteOff:
+ break;
+ }
+ break;
+
+ // Channel Pressure
+ case 12:
+ break;
+
+ // Pitch Bend
+ case 14:
+ PC = 15;
+ break;
+
+ case 15:
+ PC = 14;
+ gPitchBendBuf[MidiCh] = (MByte[1] << 1) | (MByte[0] >> 6);
+ break;
+
+ default:
+ break;
+ }
+}
+
+//-------------------------------------------------------------
+// Note ON Message Processing
+
+void NoteON(void)
+{
+ unsigned char i;
+ unsigned char h = 0; // higheest note
+
+ // ignore note if registed buffer
+ for(i = 0; i < NoteCnt[MidiCh]; i++) {
+ if(NoteBuf[MidiCh][i] == MByte[0]) {
+ return;
+ }
+ }
+
+ // full note buffer?
+ if(NoteCnt[MidiCh] == MAX_NOTE_CNT) {
+ for(i = 0; i < (MAX_NOTE_CNT - 1); i++) {
+ NoteBuf[MidiCh][i] = NoteBuf[MidiCh][i+1];
+ }
+ NoteBuf[MidiCh][MAX_NOTE_CNT - 1] = MByte[0];
+ }
+ else {
+ NoteBuf[MidiCh][NoteCnt[MidiCh]] = MByte[0];
+ NoteCnt[MidiCh]++;
+ }
+
+ // set highest note
+ for(i = 0; i < NoteCnt[MidiCh]; i++) {
+ if(h < NoteBuf[MidiCh][i]) {
+ h = NoteBuf[MidiCh][i];
+ }
+ }
+ gPlayNoteBuf[MidiCh] = h;
+ gGateBuf[MidiCh] = ON;
+}
+
+//-------------------------------------------------------------
+// Note OFF Message Processing
+
+void NoteOFF(void)
+{
+ unsigned char i;
+ unsigned char h = 0; // highest note
+ int flg = FALSE;
+
+ // Delete Note If Registed Buffer
+ for(i = 0; i < NoteCnt[MidiCh]; i++) {
+ if(flg) {
+ NoteBuf[MidiCh][i-1] = NoteBuf[MidiCh][i];
+ }
+ if(NoteBuf[MidiCh][i] == MByte[0]) {
+ flg = TRUE;
+ }
+ }
+ if(flg) NoteCnt[MidiCh]--;
+
+ if(NoteCnt[MidiCh] == 0) {
+ // Empty Buffer then Gate OFF
+ gGateBuf[MidiCh] = OFF;
+ }
+ else {
+ // Highest Note
+ for(i = 0; i < NoteCnt[MidiCh]; i++) {
+ if( h < NoteBuf[MidiCh][i]) {
+ h = NoteBuf[MidiCh][i];
+ }
+ }
+ gPlayNoteBuf[MidiCh] = h;
+ }
+}
+