MIDI message transceiver. More...

#include <stdbool.h>
#include <stdint.h>
#include <avr/io.h>
#include "gpio.h"

Include dependency graph for midi.h:

This graph shows which files directly or indirectly include this file:

Data Structures
struct	midi_event_handlers
	Pointers to MIDI message handling callbacks. More...

struct	midi_config
	MIDI transceiver module configuration. More...

Macros
#define	BAUD_RATE 31250
	MIDI baudrate. More...

#define	MIDI_UART USARTE0
	UART used for MIDI I/O. More...

#define	MIDI_CHANNEL_MASK 0x0f
	Bitmask for the channel in the MIDI status byte. More...

#define	MIDI_MESSAGE_TYPE_MASK 0xf0
	Bitmask for the message type in the MIDI status byte. More...

#define	MIDI_MAX_VALUE 127
	Maximum MIDI value. More...

Typedefs
typedef uint8_t	midi_value_t
	Type for valid MIDI values [0..127]. More...

Enumerations
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 }
	MIDI status byte values (second nibble) More...

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 }
	MIDI status byte values (first nibble) More...

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 }
	States in the MIDI state machine. More...

Functions
static bool	uart_is_ready (void)
	Checks if the UART is ready to send data. More...

static void	uart_write (uint8_t data)
	Sends one byte of date over the UART. More...

void	init_midi_module (const struct midi_config *config)
	Initializes the MIDI transceiver module. More...

enum midi_channel	read_midi_channel_from_jumpers (const struct jumpers *jumpers)
	Reads the MIDI channel configuration from the solder jumpers. More...

void	send_control_change (midi_value_t controller, midi_value_t value)
	Sends a control change message. More...

void	send_midi_message (enum midi_channel channel, enum midi_message_type type, midi_value_t data0, midi_value_t data1)
	Sends an arbitrary MIDI message. More...

void	send_note_off (midi_value_t note, midi_value_t velocity)
	Sends a note off message. More...

void	send_note_on (midi_value_t note, midi_value_t velocity)
	Sends a note on message. More...

void	send_program_change (midi_value_t program)
	Sends a program change message. More...

void	set_midi_rx_channel (enum midi_channel channel)
	Updates the midi receive channel. More...

void	set_midi_tx_channel (enum midi_channel channel)
	Updates the midi transmit channel. More...

void	set_omni_mode (bool enable)
	Puts the device into Omni mode. More...

Detailed Description

MIDI message transceiver.

Macro Definition Documentation

◆ BAUD_RATE

#define BAUD_RATE 31250

MIDI baudrate.

◆ MIDI_CHANNEL_MASK

#define MIDI_CHANNEL_MASK 0x0f

Bitmask for the channel in the MIDI status byte.

◆ MIDI_MAX_VALUE

#define MIDI_MAX_VALUE 127

Maximum MIDI value.

◆ MIDI_MESSAGE_TYPE_MASK

#define MIDI_MESSAGE_TYPE_MASK 0xf0

Bitmask for the message type in the MIDI status byte.

◆ MIDI_UART

#define MIDI_UART USARTE0

UART used for MIDI I/O.

Typedef Documentation

◆ midi_value_t

typedef uint8_t midi_value_t

Type for valid MIDI values [0..127].

Enumeration Type Documentation

◆ midi_channel

enum midi_channel

MIDI status byte values (second nibble)

Enumerator
MIDI_CHANNEL_01	MIDI channel 1.
MIDI_CHANNEL_02	MIDI channel 2.
MIDI_CHANNEL_03	MIDI channel 3.
MIDI_CHANNEL_04	MIDI channel 4.
MIDI_CHANNEL_05	MIDI channel 5.
MIDI_CHANNEL_06	MIDI channel 6.
MIDI_CHANNEL_07	MIDI channel 7.
MIDI_CHANNEL_08	MIDI channel 8.
MIDI_CHANNEL_09	MIDI channel 9.
MIDI_CHANNEL_10	MIDI channel 10.
MIDI_CHANNEL_11	MIDI channel 11.
MIDI_CHANNEL_12	MIDI channel 12.
MIDI_CHANNEL_13	MIDI channel 13.
MIDI_CHANNEL_14	MIDI channel 14.
MIDI_CHANNEL_15	MIDI channel 15.
MIDI_CHANNEL_16	MIDI channel 16.

◆ midi_message_type

enum midi_message_type

MIDI status byte values (first nibble)

Enumerator
MIDI_MSG_TYPE_CONTROL_CHANGE	Control change message.
MIDI_MSG_TYPE_NOTE_OFF	Note off message.
MIDI_MSG_TYPE_NOTE_ON	Note on message.
MIDI_MSG_TYPE_PROGRAM_CHANGE	Program change message.

◆ midi_state

enum midi_state

States in the MIDI state machine.

Enumerator
MIDI_STATE_IDLE	No pending MIDI message bytes.
MIDI_STATE_CONTROL_CHANGE_NUMBER	Control change message status byte read; awaiting controller number.
MIDI_STATE_CONTROL_CHANGE_VALUE	Control change message controller number read; awaiting value.
MIDI_STATE_NOTE_OFF_NUMBER	Note off message status byte read; awaiting note number.
MIDI_STATE_NOTE_OFF_VALUE	Note off message note number read; awaiting velocity.
MIDI_STATE_NOTE_ON_NUMBER	Note on message status byte read; awaiting note number.
MIDI_STATE_NOTE_ON_VALUE	Note on message note number read; awaiting velocity.
MIDI_STATE_PROGRAM_CHANGE	Program change message status byte read.

Function Documentation

◆ init_midi_module()

void init_midi_module ( const struct midi_config * config )

Initializes the MIDI transceiver module.

Configures the UART, enables the RXC interrupt and registers MIDI message handlers.

Parameters

config the MIDI module configuration to apply

◆ read_midi_channel_from_jumpers()

enum midi_channel read_midi_channel_from_jumpers ( const struct jumpers * jumpers )

Reads the MIDI channel configuration from the solder jumpers.

Parameters

jumpers the the solder jumpers configuration struct

Returns: the selected MIDI channel

◆ send_control_change()

void send_control_change	(	midi_value_t	controller,
		midi_value_t	value
	)

Sends a control change message.

Parameters

controller	the MIDI controller number
value	the new value for the controller

◆ send_midi_message()

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

Sends an arbitrary MIDI message.

If the second data byte is not required for the specified message type, the parameter is simply ignored.

Parameters

channel	the MIDI channel to send on
type	the type of the MIDI message to send
data0	the first data byte (e.g. MIDI controller number for a control change)
data1	the second data byte (optional, e.g. value for a control change)

◆ send_note_off()

void send_note_off	(	midi_value_t	note,
		midi_value_t	velocity
	)

Sends a note off message.

Parameters

note	the MIDI note number
velocity	velocity of the key press

◆ send_note_on()

void send_note_on	(	midi_value_t	note,
		midi_value_t	velocity
	)

Sends a note on message.

Parameters

note	the MIDI note number
velocity	velocity of the key press

◆ send_program_change()

void send_program_change ( midi_value_t program )

Sends a program change message.

Parameters

program the new MIDI program to load

◆ set_midi_rx_channel()

void set_midi_rx_channel ( enum midi_channel channel )

Updates the midi receive channel.

Parameters

channel the channel to listen on

◆ set_midi_tx_channel()

void set_midi_tx_channel ( enum midi_channel channel )

Updates the midi transmit channel.

Parameters

channel the channel to talk on

◆ set_omni_mode()

void set_omni_mode ( bool enable )

Puts the device into Omni mode.

In Omni mode the device handles all received MIDI messages regardless of the channel. When not in Omni mode, only messages on the configured receive channel are processed.

Parameters

enable if true, Omni mode is enabled; if false, it is disabled

◆ uart_is_ready()

static bool uart_is_ready ( void )

inlinestatic

Checks if the UART is ready to send data.

Returns: true if the UART is ready; false otherwise

◆ uart_write()

static void uart_write ( uint8_t data )

inlinestatic

Sends one byte of date over the UART.

Parameters

data	the data byte to send

Data Structures

Macros

Typedefs

Enumerations

Functions

Detailed Description

Macro Definition Documentation

◆ BAUD_RATE

◆ MIDI_CHANNEL_MASK

◆ MIDI_MAX_VALUE

◆ MIDI_MESSAGE_TYPE_MASK

◆ MIDI_UART

Typedef Documentation

◆ midi_value_t

Enumeration Type Documentation

◆ midi_channel

◆ midi_message_type

◆ midi_state

Function Documentation

◆ init_midi_module()

◆ read_midi_channel_from_jumpers()

◆ send_control_change()

◆ send_midi_message()

◆ send_note_off()

◆ send_note_on()

◆ send_program_change()

◆ set_midi_rx_channel()

◆ set_midi_tx_channel()

◆ set_omni_mode()

◆ uart_is_ready()

◆ uart_write()