Utility class for MIDI over Bluetooth LE

Dependencies:   BLE_API mbed nRF51822

Using MIDI over Bluetooth LE

This class enables sending and receiving MIDI packets.

Set up an "BLEMIDI" class instance

Create an instance, and set up to start using it.

Initialization

#include "mbed.h"
#include "BLEDevice.h"
#include "BLEMIDI.h"

BLEDevice device;
BLEMIDI bleMidi(&device);

void disconnectionCallback(Gap::Handle_t handle, Gap::DisconnectionReason_t reason) {
    bleMidi.onBleDisconnection(handle, reason);
}

void connectionCallback(Gap::Handle_t handle, Gap::addr_type_t type, const Gap::address_t addr, const Gap::ConnectionParams_t *params) {
    bleMidi.onBleConnection(handle, type, addr, params);
}

int main(void) {
    device.onConnection(connectionCallback);
    device.onDisconnection(disconnectionCallback);
    
    for (;;) {
        device.waitForEvent();
    }
}

Changing the device name

The default device name is 'MIDI'.
If the another name is preferred, use this constructor. The maximum length of device name is 4 bytes.

Constructor with device name

BLEDevice device;
// BLEMIDI bleMidi(&device);
BLEMIDI bleMidi(&device, "NAME");

Sending MIDI events

For example, send a note on event:

send a note on event

bleMidi.sendNoteOn(0, 63, 127);

About other events, see the BLEMIDI class reference.

Receiving MIDI events

For example, receive note on events:

receive note on events

void onNoteOn(uint8_t channel, uint8_t note, uint8_t velocity) {
    // do something with Note On event
}

bleMidi.attachNoteOn(onNoteOn);

About other events, see the BLEMIDI class reference.

BLEMIDI.h

Committer:
kshoji
Date:
2015-04-02
Revision:
0:83889dc90473
Child:
1:cba2eba64f5c

File content as of revision 0:83889dc90473:

/* Copyright (c) 2014 mbed.org, MIT License
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy of this software
 * and associated documentation files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all copies or
 * substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
 * BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#ifndef __BLEMIDI_H__
#define __BLEMIDI_H__

#include "BLEDevice.h"

/** 
 * A class to communicate a BLE MIDI device
 */
class BLEMIDI {
public:
    /**
     * Constructor
     */
    BLEMIDI(BLEDevice *device);

    /**
     * Check if a BLE MIDI device is connected
     *
     * @returns true if a midi device is connected
     */
    bool connected();

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onTuneRequest();
     */
    inline void attachTuneRequest(void (*fn)()) {
        onTuneRequest = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onTimingClock();
     */
    inline void attachTimingClock(void (*fn)()) {
        onTimingClock = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onStart();
     */
    inline void attachStart(void (*fn)()) {
        onStart = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onContinue();
     */
    inline void attachContinue(void (*fn)()) {
        onContinue = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onStop();
     */
    inline void attachStop(void (*fn)()) {
        onStop = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onActiveSensing();
     */
    inline void attachActiveSensing(void (*fn)()) {
        onActiveSensing = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onReset();
     */
    inline void attachReset(void (*fn)()) {
        onReset = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onProgramChange(uint8_t, uint8_t);
     */
    inline void attachnProgramChange(void (*fn)(uint8_t, uint8_t)) {
        onProgramChange = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onChannelAftertouch(uint8_t, uint8_t);
     */
    inline void attachChannelAftertouch(void (*fn)(uint8_t, uint8_t)) {
        onChannelAftertouch = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onTimeCodeQuarterFrame(uint8_t);
     */
    inline void attachTimeCodeQuarterFrame(void (*fn)(uint8_t)) {
        onTimeCodeQuarterFrame = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onSongSelect(uint8_t);
     */
    inline void attachSongSelect(void (*fn)(uint8_t)) {
        onSongSelect = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onNoteOff(uint8_t, uint8_t, uint8_t);
     */
    inline void attachNoteOff(void (*fn)(uint8_t, uint8_t, uint8_t)) {
        onNoteOff = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onNoteOn(uint8_t, uint8_t, uint8_t);
     */
    inline void attachNoteOn(void (*fn)(uint8_t, uint8_t, uint8_t)) {
        onNoteOn = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onPolyphonicAftertouch(uint8_t, uint8_t, uint8_t);
     */
    inline void attachPolyphonicAftertouch(void (*fn)(uint8_t, uint8_t, uint8_t)) {
        onPolyphonicAftertouch = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onControlChange(uint8_t, uint8_t, uint8_t);
     */
    inline void attachControlChange(void (*fn)(uint8_t, uint8_t, uint8_t)) {
        onControlChange = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onPitchWheel(uint8_t, uint16_t);
     */
    inline void attachPitchWheel(void (*fn)(uint8_t, uint16_t)) {
        onPitchWheel = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onSongPositionPointer(uint16_t);
     */
    inline void attachSongPositionPointer(void (*fn)(uint16_t)) {
        onSongPositionPointer = fn;
    }

    /**
     * Attach a callback called when the MIDI event is received
     *
     * @param ptr function pointer
     *   prototype: void onSystemExclusive(uint8_t *, uint16_t);
     */
    inline void attachSystemExclusive(void (*fn)(uint8_t *, uint16_t)) {
        onSystemExclusive = fn;
    }

    void sendTuneRequest();
    void sendTimingClock();
    void sendStart();
    void sendContinue();
    void sendStop();
    void sendActiveSensing();
    void sendReset();
    void sendProgramChange(uint8_t channel, uint8_t program);
    void sendChannelAftertouch(uint8_t channel, uint8_t pressure);
    void sendTimeCodeQuarterFrame(uint8_t timing);
    void sendSongSelect(uint8_t song);
    void sendNoteOff(uint8_t channel, uint8_t note, uint8_t velocity);
    void sendNoteOn(uint8_t channel, uint8_t note, uint8_t velocity);
    void sendPolyphonicAftertouch(uint8_t channel, uint8_t note, uint8_t pressure);
    void sendControlChange(uint8_t channel, uint8_t function, uint8_t value);
    void sendPitchWheel(uint8_t channel, uint16_t amount);
    void sendSongPositionPointer(uint16_t position);
    void sendSystemExclusive(uint8_t * sysex, uint16_t length);

    void onBleDisconnection(Gap::Handle_t handle, Gap::DisconnectionReason_t reason);
    void onBleConnection(Gap::Handle_t handle, Gap::addr_type_t type, const Gap::address_t addr, const Gap::ConnectionParams_t *params);


private:
    bool isConnected;

    uint16_t sysExBufferPos;
    uint8_t sysExBuffer[256];

    uint16_t timestamp;

    uint8_t midiEventKind;
    uint8_t midiEventNote;
    uint8_t midiEventVelocity;

    enum MIDI_STATE {
        MIDI_STATE_TIMESTAMP = 0,
        MIDI_STATE_WAIT,
        MIDI_STATE_SIGNAL_2BYTES_2,
        MIDI_STATE_SIGNAL_3BYTES_2,
        MIDI_STATE_SIGNAL_3BYTES_3,
        MIDI_STATE_SIGNAL_SYSEX
    };

    MIDI_STATE midiState;

    void (*onTuneRequest)();
    void (*onTimingClock)();
    void (*onStart)();
    void (*onContinue)();
    void (*onStop)();
    void (*onActiveSensing)();
    void (*onReset)();
    void (*onProgramChange)(uint8_t, uint8_t);
    void (*onChannelAftertouch)(uint8_t, uint8_t);
    void (*onTimeCodeQuarterFrame)(uint8_t);
    void (*onSongSelect)(uint8_t);
    void (*onNoteOff)(uint8_t, uint8_t, uint8_t);
    void (*onNoteOn)(uint8_t, uint8_t, uint8_t);
    void (*onPolyphonicAftertouch)(uint8_t, uint8_t, uint8_t);
    void (*onControlChange)(uint8_t, uint8_t, uint8_t);
    void (*onPitchWheel)(uint8_t, uint16_t);
    void (*onSongPositionPointer)(uint16_t);
    void (*onSystemExclusive)(uint8_t *, uint16_t);

    void sendMidiMessage(uint8_t data0);
    void sendMidiMessage(uint8_t data0, uint8_t data1);
    void sendMidiMessage(uint8_t data0, uint8_t data1, uint8_t data2);

    void dataWrittenCallback(const GattCharacteristicWriteCBParams *params);

    BLEDevice *device;
    GattCharacteristic *midiCharacteristic;    
    Timer tick;
};

#endif /* __BLEMIDI_H__ */