keychron_qmk_firmware/docs/internals/midi_device.md

# group `midi_device` {#group__midi__device}

You use the functions when you are implementing your own midi device.

You set a send function to actually send bytes via your device, this method is called when you call a send function with this device, for instance midi_send_cc

You use the midi_device_input to process input data from the device and pass it through the device's associated callbacks.

You use the midi_device_set_pre_input_process_func if you want to have a function called at the beginning of the device's process function, generally to poll for input and pass that into midi_device_input

## Summary

 Members                        | Descriptions                                
--------------------------------|---------------------------------------------
`define `[`MIDI_INPUT_QUEUE_LENGTH`](#group__midi__device_1ga4aaa419caebdca2bbdfc1331e79781a8)            | 
`enum `[`input_state_t`](#group__midi__device_1gac203e877d3df4275ceb8e7180a61f621)            | 
`public void `[`midi_device_input`](#group__midi__device_1gad8d3db8eb35d9cfa51ef036a0a9d70db)`(`[`MidiDevice`](#struct__midi__device)` * device,uint8_t cnt,uint8_t * input)`            | Process input bytes. This function parses bytes and calls the appropriate callbacks associated with the given device. You use this function if you are creating a custom device and you want to have midi input.
`public void `[`midi_device_set_send_func`](#group__midi__device_1ga59f5a46bdd4452f186cc73d9e96d4673)`(`[`MidiDevice`](#struct__midi__device)` * device,midi_var_byte_func_t send_func)`            | Set the callback function that will be used for sending output data bytes. This is only used if you're creating a custom device. You'll most likely want the callback function to disable interrupts so that you can call the various midi send functions without worrying about locking.
`public void `[`midi_device_set_pre_input_process_func`](#group__midi__device_1ga4de0841b87c04fc23cb56b6451f33b69)`(`[`MidiDevice`](#struct__midi__device)` * device,midi_no_byte_func_t pre_process_func)`            | Set a callback which is called at the beginning of the midi_device_process call. This can be used to poll for input data and send the data through the midi_device_input function. You'll probably only use this if you're creating a custom device.
`struct `[`_midi_device`](docs/api_midi_device.md#struct__midi__device) | This structure represents the input and output functions and processing data for a midi device.

## Members

#### `define `[`MIDI_INPUT_QUEUE_LENGTH`](#group__midi__device_1ga4aaa419caebdca2bbdfc1331e79781a8) {#group__midi__device_1ga4aaa419caebdca2bbdfc1331e79781a8}

#### `enum `[`input_state_t`](#group__midi__device_1gac203e877d3df4275ceb8e7180a61f621) {#group__midi__device_1gac203e877d3df4275ceb8e7180a61f621}

 Values                         | Descriptions                                
--------------------------------|---------------------------------------------
IDLE            | 
ONE_BYTE_MESSAGE            | 
TWO_BYTE_MESSAGE            | 
THREE_BYTE_MESSAGE            | 
SYSEX_MESSAGE            | 

#### `public void `[`midi_device_input`](#group__midi__device_1gad8d3db8eb35d9cfa51ef036a0a9d70db)`(`[`MidiDevice`](#struct__midi__device)` * device,uint8_t cnt,uint8_t * input)` {#group__midi__device_1gad8d3db8eb35d9cfa51ef036a0a9d70db}

Process input bytes. This function parses bytes and calls the appropriate callbacks associated with the given device. You use this function if you are creating a custom device and you want to have midi input.

#### Parameters
* `device` the midi device to associate the input with 

* `cnt` the number of bytes you are processing 

* `input` the bytes to process

#### `public void `[`midi_device_set_send_func`](#group__midi__device_1ga59f5a46bdd4452f186cc73d9e96d4673)`(`[`MidiDevice`](#struct__midi__device)` * device,midi_var_byte_func_t send_func)` {#group__midi__device_1ga59f5a46bdd4452f186cc73d9e96d4673}

Set the callback function that will be used for sending output data bytes. This is only used if you're creating a custom device. You'll most likely want the callback function to disable interrupts so that you can call the various midi send functions without worrying about locking.

#### Parameters
* `device` the midi device to associate this callback with 

* `send_func` the callback function that will do the sending

#### `public void `[`midi_device_set_pre_input_process_func`](#group__midi__device_1ga4de0841b87c04fc23cb56b6451f33b69)`(`[`MidiDevice`](#struct__midi__device)` * device,midi_no_byte_func_t pre_process_func)` {#group__midi__device_1ga4de0841b87c04fc23cb56b6451f33b69}

Set a callback which is called at the beginning of the midi_device_process call. This can be used to poll for input data and send the data through the midi_device_input function. You'll probably only use this if you're creating a custom device.

#### Parameters
* `device` the midi device to associate this callback with 

* `midi_no_byte_func_t` the actual callback function

# struct `_midi_device` {#struct__midi__device}

This structure represents the input and output functions and processing data for a midi device.

A device can represent an actual physical device [serial port, usb port] or something virtual. You should not need to modify this structure directly.

## Summary

 Members                        | Descriptions                                
--------------------------------|---------------------------------------------
`public midi_var_byte_func_t `[`send_func`](docs/api_midi_device.md#struct__midi__device_1a25d4c94b4bbccd5b98f1032b469f3ff9) | 
`public midi_three_byte_func_t `[`input_cc_callback`](docs/api_midi_device.md#struct__midi__device_1a6da5236c1bc73877728df92d213a78d1) | 
`public midi_three_byte_func_t `[`input_noteon_callback`](docs/api_midi_device.md#struct__midi__device_1aa10b15cf1a7fb825a5df0d2abbe34a1c) | 
`public midi_three_byte_func_t `[`input_noteoff_callback`](docs/api_midi_device.md#struct__midi__device_1aaf290043078534d3a5a0ea4c840eba84) | 
`public midi_three_byte_func_t `[`input_aftertouch_callback`](docs/api_midi_device.md#struct__midi__device_1acb0b4901c545cec4b28b126f2d8c315f) | 
`public midi_three_byte_func_t `[`input_pitchbend_callback`](docs/api_midi_device.md#struct__midi__device_1a305fea672caeb996f2233bf8cd2bef18) | 
`public midi_three_byte_func_t `[`input_songposition_callback`](docs/api_midi_device.md#struct__midi__device_1a5f3f13638b3fef3fc561ed1bf301d586) | 
`public midi_two_byte_func_t `[`input_progchange_callback`](docs/api_midi_device.md#struct__midi__device_1adaf1da617c9a10a9dcad00ab1959d3da) | 
`public midi_two_byte_func_t `[`input_chanpressure_callback`](docs/api_midi_device.md#struct__midi__device_1ab7ca2925c539915d43974eff604d85f7) | 
`public midi_two_byte_func_t `[`input_songselect_callback`](docs/api_midi_device.md#struct__midi__device_1a89bed8a5a55376120cfc0a62b42f057f) | 
`public midi_two_byte_func_t `[`input_tc_quarterframe_callback`](docs/api_midi_device.md#struct__midi__device_1ad9813e75d22e284f9f65a907d20600f0) | 
`public midi_one_byte_func_t `[`input_realtime_callback`](docs/api_midi_device.md#struct__midi__device_1a9448eba4afb7e43650434748db3777be) | 
`public midi_one_byte_func_t `[`input_tunerequest_callback`](docs/api_midi_device.md#struct__midi__device_1a0cb8fd53e00cf1d4202d4fa04d038e8d) | 
`public midi_sysex_func_t `[`input_sysex_callback`](docs/api_midi_device.md#struct__midi__device_1afff9a0ce641762aaef24c1e6953ec9a2) | 
`public midi_var_byte_func_t `[`input_fallthrough_callback`](docs/api_midi_device.md#struct__midi__device_1abb974ec6d734001b4a0e370f292be503) | 
`public midi_var_byte_func_t `[`input_catchall_callback`](docs/api_midi_device.md#struct__midi__device_1aae0d535129d4fd650edc98eb3f7584f8) | 
`public midi_no_byte_func_t `[`pre_input_process_callback`](docs/api_midi_device.md#struct__midi__device_1aeb0bb8923d66c23d874e177dc4265754) | 
`public uint8_t `[`input_buffer`](docs/api_midi_device.md#struct__midi__device_1a7c5684857d6af4ebc4dc12da27bd6b2a) | 
`public input_state_t `[`input_state`](docs/api_midi_device.md#struct__midi__device_1a69a687d2d1c449ec15a11c07a5722e39) | 
`public uint16_t `[`input_count`](docs/api_midi_device.md#struct__midi__device_1a68dea8e7b6151e89c85c95caa612ee5d) | 
`public uint8_t `[`input_queue_data`](docs/api_midi_device.md#struct__midi__device_1ada41de021135dc423abedcbb30f366ff) | 
`public `[`byteQueue_t`](#structbyte_queue__t)` `[`input_queue`](#struct__midi__device_1a49c8538a8a02193c58e28a56eb695d8f) | 

## Members

#### `public midi_var_byte_func_t `[`send_func`](docs/api_midi_device.md#struct__midi__device_1a25d4c94b4bbccd5b98f1032b469f3ff9) {#struct__midi__device_1a25d4c94b4bbccd5b98f1032b469f3ff9}

#### `public midi_three_byte_func_t `[`input_cc_callback`](docs/api_midi_device.md#struct__midi__device_1a6da5236c1bc73877728df92d213a78d1) {#struct__midi__device_1a6da5236c1bc73877728df92d213a78d1}

#### `public midi_three_byte_func_t `[`input_noteon_callback`](docs/api_midi_device.md#struct__midi__device_1aa10b15cf1a7fb825a5df0d2abbe34a1c) {#struct__midi__device_1aa10b15cf1a7fb825a5df0d2abbe34a1c}

#### `public midi_three_byte_func_t `[`input_noteoff_callback`](docs/api_midi_device.md#struct__midi__device_1aaf290043078534d3a5a0ea4c840eba84) {#struct__midi__device_1aaf290043078534d3a5a0ea4c840eba84}

#### `public midi_three_byte_func_t `[`input_aftertouch_callback`](docs/api_midi_device.md#struct__midi__device_1acb0b4901c545cec4b28b126f2d8c315f) {#struct__midi__device_1acb0b4901c545cec4b28b126f2d8c315f}

#### `public midi_three_byte_func_t `[`input_pitchbend_callback`](docs/api_midi_device.md#struct__midi__device_1a305fea672caeb996f2233bf8cd2bef18) {#struct__midi__device_1a305fea672caeb996f2233bf8cd2bef18}

#### `public midi_three_byte_func_t `[`input_songposition_callback`](docs/api_midi_device.md#struct__midi__device_1a5f3f13638b3fef3fc561ed1bf301d586) {#struct__midi__device_1a5f3f13638b3fef3fc561ed1bf301d586}

#### `public midi_two_byte_func_t `[`input_progchange_callback`](docs/api_midi_device.md#struct__midi__device_1adaf1da617c9a10a9dcad00ab1959d3da) {#struct__midi__device_1adaf1da617c9a10a9dcad00ab1959d3da}

#### `public midi_two_byte_func_t `[`input_chanpressure_callback`](docs/api_midi_device.md#struct__midi__device_1ab7ca2925c539915d43974eff604d85f7) {#struct__midi__device_1ab7ca2925c539915d43974eff604d85f7}

#### `public midi_two_byte_func_t `[`input_songselect_callback`](docs/api_midi_device.md#struct__midi__device_1a89bed8a5a55376120cfc0a62b42f057f) {#struct__midi__device_1a89bed8a5a55376120cfc0a62b42f057f}

#### `public midi_two_byte_func_t `[`input_tc_quarterframe_callback`](docs/api_midi_device.md#struct__midi__device_1ad9813e75d22e284f9f65a907d20600f0) {#struct__midi__device_1ad9813e75d22e284f9f65a907d20600f0}

#### `public midi_one_byte_func_t `[`input_realtime_callback`](docs/api_midi_device.md#struct__midi__device_1a9448eba4afb7e43650434748db3777be) {#struct__midi__device_1a9448eba4afb7e43650434748db3777be}

#### `public midi_one_byte_func_t `[`input_tunerequest_callback`](docs/api_midi_device.md#struct__midi__device_1a0cb8fd53e00cf1d4202d4fa04d038e8d) {#struct__midi__device_1a0cb8fd53e00cf1d4202d4fa04d038e8d}

#### `public midi_sysex_func_t `[`input_sysex_callback`](docs/api_midi_device.md#struct__midi__device_1afff9a0ce641762aaef24c1e6953ec9a2) {#struct__midi__device_1afff9a0ce641762aaef24c1e6953ec9a2}

#### `public midi_var_byte_func_t `[`input_fallthrough_callback`](docs/api_midi_device.md#struct__midi__device_1abb974ec6d734001b4a0e370f292be503) {#struct__midi__device_1abb974ec6d734001b4a0e370f292be503}

#### `public midi_var_byte_func_t `[`input_catchall_callback`](docs/api_midi_device.md#struct__midi__device_1aae0d535129d4fd650edc98eb3f7584f8) {#struct__midi__device_1aae0d535129d4fd650edc98eb3f7584f8}

#### `public midi_no_byte_func_t `[`pre_input_process_callback`](docs/api_midi_device.md#struct__midi__device_1aeb0bb8923d66c23d874e177dc4265754) {#struct__midi__device_1aeb0bb8923d66c23d874e177dc4265754}

#### `public uint8_t `[`input_buffer`](docs/api_midi_device.md#struct__midi__device_1a7c5684857d6af4ebc4dc12da27bd6b2a) {#struct__midi__device_1a7c5684857d6af4ebc4dc12da27bd6b2a}

#### `public input_state_t `[`input_state`](docs/api_midi_device.md#struct__midi__device_1a69a687d2d1c449ec15a11c07a5722e39) {#struct__midi__device_1a69a687d2d1c449ec15a11c07a5722e39}

#### `public uint16_t `[`input_count`](docs/api_midi_device.md#struct__midi__device_1a68dea8e7b6151e89c85c95caa612ee5d) {#struct__midi__device_1a68dea8e7b6151e89c85c95caa612ee5d}

#### `public uint8_t `[`input_queue_data`](docs/api_midi_device.md#struct__midi__device_1ada41de021135dc423abedcbb30f366ff) {#struct__midi__device_1ada41de021135dc423abedcbb30f366ff}

#### `public `[`byteQueue_t`](#structbyte_queue__t)` `[`input_queue`](#struct__midi__device_1a49c8538a8a02193c58e28a56eb695d8f) {#struct__midi__device_1a49c8538a8a02193c58e28a56eb695d8f}