Merge pull request #12 from anarkiwi/msgs

rearrange config messages, allow masking of status messages.

README.md

@@ -13,6 +13,7 @@ Vessel's main points of differences from other C64 MIDI interfaces are:
 * it uses the user port, not the cartridge port
 * it does not use/need any CIA shift register ports
 * it can transfer multiple bytes per transaction (unlike ACIA/6850 designs)
+* the C64 can have configure Vessel to filter MIDI messages to save CPU time
 
 If you are interested in acquiring a Vessel please contact [email protected].
 
@@ -67,12 +68,17 @@ The C64 can send Vessel a command, by sending byte 0xFD (not used by MIDI),
 and then a command, and then a fixed number of data bytes (depending on the
 command - unless otherwise specified, a command is followed by 0 data bytes).
 
-By default, NMI on external input is off, all MIDI channels are masked (only
-channel-less messages will be sent to the C64), and MIDI through is disabled.
-
-* 0x00 HH LL CN: Config: channel mask high byte (HH), low byte (LL), and config byte (CN). Config byte bit 0 enables NMI, bit 1 enables MIDI through.
-* 0x01: Reset. Vessel will reset to default config,
-* 0x02: Version. Vessel will return a version string (currently ASCII "vessel0").
+By default, NMI on external input is off, all MIDI channels are masked and
+all status messages will be masked (no MIDI messages will be sent to the C64)
+and MIDI through is disabled.
+
+|byte|command |arg bytes|description
+|----|------------|---------|--------------------------------------------------------------------------
+|0x00|Reset | |Vessel will reset to default config,
+|0x01|Version | |Vessel will return a version string (currently C64 screen code "vessel00").
+|0x02|Config |CF |CF bit 0 enables NMI, bit 1 enables MIDI through.
+|0x03|Channel mask|HH LL |High byte (HH), low byte (LL) for channels 1 to 16
+|0x04|Status mask |HH LL |High byte (HH), low byte (LL) for messages F0 to FF
 
 
 Upgrading firmware

vessel.ino

@@ -105,21 +105,26 @@ volatile byte outBufWritePtr = 0;
 volatile byte *outBufReadPtr = outBuf;
 volatile IsrModeEnum isrMode = ISR_INPUT;
 volatile uint16_t receiveChannelMask = 0;
+volatile uint16_t receiveStatusMask = 0;
 volatile bool nmiEnabled = false;
 
 void (*cmds[])(void) = {
- configCmd,
  resetCmd,
  versionCmd,
+ configFlagsCmd,
+ configChannelCmd,
+ configStatusCmd,
 };
+void (*cmd)(void) = NULL;
 const byte cmdLens[] = {
- 3,
  0,
  0,
+ 1,
+ 2,
+ 2,
 };
-byte const *cmdLen = cmdLens;
-volatile byte *cmdByte = inCmdBuf + 1;
-const byte maxCmd = sizeof(cmdLens) - 1;
+volatile byte cmdLen = 0;
+const byte maxCmd = 4;
 
 class FakeSerial {
  public:
@@ -167,6 +172,7 @@ MIDI_CREATE_CUSTOM_INSTANCE(FakeSerial, fs, MIDI, VesselSettings);
 #define NMI_MIDI_SEND(x) NMI_WRAP(MIDI.x)
 
 #define NMI_CHANNEL_SEND(x) if (channelMasked(channel)) { NMI_MIDI_SEND(x) }
+#define NMI_STATUS_SEND(x, y) if (statusMasked(x)) { NMI_MIDI_SEND(y) }
 
 inline void handleNoteOn(byte channel, byte note, byte velocity) {
  NMI_CHANNEL_SEND(sendNoteOn(note, velocity, channel))
@@ -197,39 +203,44 @@ inline void handlePitchBend(byte channel, int bend) {
 }
 
 inline void handleTimeCodeQuarterFrame(byte data) {
- NMI_MIDI_SEND(sendTimeCodeQuarterFrame(data))
+ NMI_STATUS_SEND(midi::TimeCodeQuarterFrame, sendTimeCodeQuarterFrame(data))
 }
 
 inline void handleSongPosition(unsigned int beats) {
- NMI_MIDI_SEND(sendSongPosition(beats))
+ NMI_STATUS_SEND(midi::SongPosition, sendSongPosition(beats))
 }
 
 inline void handleSongSelect(byte songnumber) {
- NMI_MIDI_SEND(sendSongSelect(songnumber))
+ NMI_STATUS_SEND(midi::SongSelect, sendSongSelect(songnumber))
 }
 
 inline void handleTuneRequest() {
- NMI_MIDI_SEND(sendTuneRequest())
+ NMI_STATUS_SEND(midi::TuneRequest, sendTuneRequest())
 }
 
 inline void handleClock(void) {
- NMI_MIDI_SEND(sendClock())
+ NMI_STATUS_SEND(midi::Clock, sendClock())
 }
 
 inline void handleStart(void) {
- NMI_MIDI_SEND(sendStart())
+ NMI_STATUS_SEND(midi::Start, sendStart())
 }
 
 inline void handleContinue(void) {
- NMI_MIDI_SEND(sendContinue())
+ NMI_STATUS_SEND(midi::Continue, sendContinue())
 }
 
 inline void handleStop(void) {
- NMI_MIDI_SEND(sendStop())
+ NMI_STATUS_SEND(midi::Stop, sendStop())
 }
 
 inline void handleSystemReset(void) {
- NMI_MIDI_SEND(sendSystemReset())
+ NMI_STATUS_SEND(midi::SystemReset, sendSystemReset())
+}
+
+inline bool statusMasked(byte status) {
+ uint16_t mask = 1 << (status & 0xf);
+ return mask & receiveStatusMask;
 }
 
 inline bool channelMasked(byte channel) {
@@ -345,11 +356,13 @@ inline void readByte() {
 
 inline void readCmdByte() {
  inCmdBuf[++inCmdBufReadPtr] = getByte();
- if (*cmdByte > maxCmd) {
+ byte cmdNo = inCmdBuf[1];
+ if (cmdNo > maxCmd) {
  isrMode = ISR_INPUT;
  } else {
- cmdLen = cmdLens + *cmdByte;
- if (*cmdLen) {
+ cmdLen = cmdLens[cmdNo];
+ cmd = cmds[cmdNo];
+ if (cmdLen) {
  isrMode = ISR_INPUT_CMD_DATA;
  } else {
  runCmd();
@@ -367,14 +380,14 @@ inline void versionCmd() {
 
 inline void resetCmd() {
  receiveChannelMask = 0;
+ receiveStatusMask = 0;
  nmiEnabled = false;
  MIDI.turnThruOff();
  resetWritePtrs();
 }
 
-inline void configCmd() {
- receiveChannelMask = (inCmdBuf[2] << 8) + inCmdBuf[3];
- byte configFlags = inCmdBuf[4];
+inline void configFlagsCmd() {
+ byte configFlags = inCmdBuf[2];
  nmiEnabled = configFlags & 1;
  if (configFlags & 2) {
  MIDI.turnThruOn();
@@ -383,14 +396,26 @@ inline void configCmd() {
  }
 }
 
+inline uint16_t getMask() {
+ return (inCmdBuf[2] << 8) + inCmdBuf[3];
+}
+
+inline void configChannelCmd() {
+ receiveChannelMask = getMask();
+}
+
+inline void configStatusCmd() {
+ receiveStatusMask = getMask();
+}
+
 inline void runCmd() {
  isrMode = ISR_INPUT;
- cmds[*cmdByte]();
+ (*cmd)();
 }
 
 inline void readCmdData() {
  inCmdBuf[++inCmdBufReadPtr] = getByte();
- if (inCmdBufReadPtr > *cmdLen) {
+ if (inCmdBufReadPtr > cmdLen) {
  runCmd();
  }
 }