midi.h

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/*
 * Copyright 2012-2015 Sebastian Neuser
 *
 * This file is part of the uMIDI firmware.
 *
 * The uMIDI firmware is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * The uMIDI firmware is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with the uMIDI firmware.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _MIDI_H
#define _MIDI_H


//---------------- includes ----------------//
#include <stdbool.h>
#include <stdint.h>
#include <avr/io.h>

#include "gpio.h"


//---------------- constants ----------------//

#define     BAUD_RATE                   31250

#define     MIDI_UART                   USARTE0

#define     MIDI_CHANNEL_MASK           0x0f

#define     MIDI_MESSAGE_TYPE_MASK      0xf0

#define     MIDI_MAX_VALUE              127


//---------------- data types ----------------//

typedef uint8_t midi_value_t;

enum midi_channel
{
    MIDI_CHANNEL_01                 = 0x00,     
    MIDI_CHANNEL_02                 = 0x01,     
    MIDI_CHANNEL_03                 = 0x02,     
    MIDI_CHANNEL_04                 = 0x03,     
    MIDI_CHANNEL_05                 = 0x04,     
    MIDI_CHANNEL_06                 = 0x05,     
    MIDI_CHANNEL_07                 = 0x06,     
    MIDI_CHANNEL_08                 = 0x07,     
    MIDI_CHANNEL_09                 = 0x08,     
    MIDI_CHANNEL_10                 = 0x09,     
    MIDI_CHANNEL_11                 = 0x0a,     
    MIDI_CHANNEL_12                 = 0x0b,     
    MIDI_CHANNEL_13                 = 0x0c,     
    MIDI_CHANNEL_14                 = 0x0d,     
    MIDI_CHANNEL_15                 = 0x0e,     
    MIDI_CHANNEL_16                 = 0x0f      
};

enum midi_message_type
{
    MIDI_MSG_TYPE_CONTROL_CHANGE    = 0xb0,     
    MIDI_MSG_TYPE_NOTE_OFF          = 0x80,     
    MIDI_MSG_TYPE_NOTE_ON           = 0x90,     
    MIDI_MSG_TYPE_PROGRAM_CHANGE    = 0xc0,     
};

enum midi_state
{
    MIDI_STATE_IDLE,                            
    MIDI_STATE_CONTROL_CHANGE_NUMBER,           
    MIDI_STATE_CONTROL_CHANGE_VALUE,            
    MIDI_STATE_NOTE_OFF_NUMBER,                 
    MIDI_STATE_NOTE_OFF_VALUE,                  
    MIDI_STATE_NOTE_ON_NUMBER,                  
    MIDI_STATE_NOTE_ON_VALUE,                   
    MIDI_STATE_PROGRAM_CHANGE,                  
};

struct midi_event_handlers
{
    void (*control_change)(midi_value_t controller, midi_value_t value);

    void (*note_off)(midi_value_t note, midi_value_t velocity);

    void (*note_on)(midi_value_t note, midi_value_t velocity);

    void (*program_change)(midi_value_t program);
};

struct midi_config
{
    struct midi_event_handlers  event_handlers; 
    enum midi_channel           rx_channel;     
    enum midi_channel           tx_channel;     
    bool                        omni_mode;      
    bool                        signal_rx;      
};


//---------------- functions and procedures ----------------//

static inline bool uart_is_ready(void) {
    return MIDI_UART.STATUS & USART_DREIF_bm;
}

static inline void uart_write(uint8_t data) {
    while (!uart_is_ready());
    MIDI_UART.DATA = data;
}

void init_midi_module(const struct midi_config* config);

enum midi_channel read_midi_channel_from_jumpers(const struct jumpers * jumpers);

void send_control_change(midi_value_t controller, midi_value_t value);

void send_midi_message(enum midi_channel channel, enum midi_message_type type, midi_value_t data0, midi_value_t data1);

void send_note_off(midi_value_t note, midi_value_t velocity);

void send_note_on(midi_value_t note, midi_value_t velocity);

void send_program_change(midi_value_t program);

void set_midi_rx_channel(enum midi_channel channel);

void set_midi_tx_channel(enum midi_channel channel);

void set_omni_mode(bool enable);


//---------------- EOF ----------------//
#endif // _MIDI_H