midi

keyboard/planck/Config/LUFAConfig.h

@@ -0,0 +1,93 @@
+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2012.
+
+  dean [at] fourwalledcubicle [dot] com
+           www.lufa-lib.org
+*/
+
+/*
+  Copyright 2012  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, distribute, and sell this
+  software and its documentation for any purpose is hereby granted
+  without fee, provided that the above copyright notice appear in
+  all copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \file
+ *  \brief LUFA Library Configuration Header File
+ *
+ *  This header file is used to configure LUFA's compile time options,
+ *  as an alternative to the compile time constants supplied through
+ *  a makefile.
+ *
+ *  For information on what each token does, refer to the LUFA
+ *  manual section "Summary of Compile Tokens".
+ */
+
+#ifndef _LUFA_CONFIG_H_
+#define _LUFA_CONFIG_H_
+
+	#if (ARCH == ARCH_AVR8)
+
+		/* Non-USB Related Configuration Tokens: */
+//		#define DISABLE_TERMINAL_CODES
+
+		/* USB Class Driver Related Tokens: */
+//		#define HID_HOST_BOOT_PROTOCOL_ONLY
+//		#define HID_STATETABLE_STACK_DEPTH       {Insert Value Here}
+//		#define HID_USAGE_STACK_DEPTH            {Insert Value Here}
+//		#define HID_MAX_COLLECTIONS              {Insert Value Here}
+//		#define HID_MAX_REPORTITEMS              {Insert Value Here}
+//		#define HID_MAX_REPORT_IDS               {Insert Value Here}
+//		#define NO_CLASS_DRIVER_AUTOFLUSH
+
+		/* General USB Driver Related Tokens: */
+//		#define ORDERED_EP_CONFIG
+		#define USE_STATIC_OPTIONS               (USB_DEVICE_OPT_FULLSPEED | USB_OPT_REG_ENABLED | USB_OPT_AUTO_PLL)
+		#define USB_DEVICE_ONLY
+//		#define USB_HOST_ONLY
+//		#define USB_STREAM_TIMEOUT_MS            {Insert Value Here}
+//		#define NO_LIMITED_CONTROLLER_CONNECT
+//		#define NO_SOF_EVENTS
+
+		/* USB Device Mode Driver Related Tokens: */
+//		#define USE_RAM_DESCRIPTORS
+		#define USE_FLASH_DESCRIPTORS
+//		#define USE_EEPROM_DESCRIPTORS
+//		#define NO_INTERNAL_SERIAL
+		#define FIXED_CONTROL_ENDPOINT_SIZE      8
+//		#define DEVICE_STATE_AS_GPIOR            {Insert Value Here}
+		#define FIXED_NUM_CONFIGURATIONS         1
+//		#define CONTROL_ONLY_DEVICE
+//		#define INTERRUPT_CONTROL_ENDPOINT
+//		#define NO_DEVICE_REMOTE_WAKEUP
+//		#define NO_DEVICE_SELF_POWER
+
+		/* USB Host Mode Driver Related Tokens: */
+//		#define HOST_STATE_AS_GPIOR              {Insert Value Here}
+//		#define USB_HOST_TIMEOUT_MS              {Insert Value Here}
+//		#define HOST_DEVICE_SETTLE_DELAY_MS	     {Insert Value Here}
+//      #define NO_AUTO_VBUS_MANAGEMENT
+//      #define INVERTED_VBUS_ENABLE_LINE
+
+	#else
+
+		#error Unsupported architecture for this LUFA configuration file.
+
+	#endif
+#endif

protocol/lufa/midi/bytequeue/bytequeue.c

@@ -0,0 +1,65 @@
+//this is a single reader [maybe multiple writer?] byte queue
+//Copyright 2008 Alex Norman
+//writen by Alex Norman 
+//
+//This file is part of avr-bytequeue.
+//
+//avr-bytequeue 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.
+//
+//avr-bytequeue 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 avr-bytequeue.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "bytequeue.h"
+#include "interrupt_setting.h"
+
+void bytequeue_init(byteQueue_t * queue, uint8_t * dataArray, byteQueueIndex_t arrayLen){
+   queue->length = arrayLen;
+   queue->data = dataArray;
+   queue->start = queue->end = 0;
+}
+
+bool bytequeue_enqueue(byteQueue_t * queue, uint8_t item){
+   interrupt_setting_t setting = store_and_clear_interrupt();
+   //full
+   if(((queue->end + 1) % queue->length) == queue->start){
+      restore_interrupt_setting(setting);
+      return false;
+   } else {
+      queue->data[queue->end] = item;
+      queue->end = (queue->end + 1) % queue->length;
+      restore_interrupt_setting(setting);
+      return true;
+   }
+}
+
+byteQueueIndex_t bytequeue_length(byteQueue_t * queue){
+   byteQueueIndex_t len;
+   interrupt_setting_t setting = store_and_clear_interrupt();
+   if(queue->end >= queue->start)
+      len = queue->end - queue->start;
+   else
+      len = (queue->length - queue->start) + queue->end;
+   restore_interrupt_setting(setting);
+   return len;
+}
+
+//we don't need to avoid interrupts if there is only one reader
+uint8_t bytequeue_get(byteQueue_t * queue, byteQueueIndex_t index){
+   return queue->data[(queue->start + index) % queue->length];
+}
+
+//we just update the start index to remove elements
+void bytequeue_remove(byteQueue_t * queue, byteQueueIndex_t numToRemove){
+   interrupt_setting_t setting = store_and_clear_interrupt();
+   queue->start = (queue->start + numToRemove) % queue->length;
+   restore_interrupt_setting(setting);
+}
+

protocol/lufa/midi/bytequeue/bytequeue.h

@@ -0,0 +1,59 @@
+//this is a single reader [maybe multiple writer?] byte queue
+//Copyright 2008 Alex Norman
+//writen by Alex Norman 
+//
+//This file is part of avr-bytequeue.
+//
+//avr-bytequeue 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.
+//
+//avr-bytequeue 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 avr-bytequeue.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef BYTEQUEUE_H
+#define BYTEQUEUE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+typedef uint8_t byteQueueIndex_t;
+
+typedef struct {
+	byteQueueIndex_t start;
+	byteQueueIndex_t end;
+	byteQueueIndex_t length;
+	uint8_t * data;
+} byteQueue_t;
+
+//you must have a queue, an array of data which the queue will use, and the length of that array
+void bytequeue_init(byteQueue_t * queue, uint8_t * dataArray, byteQueueIndex_t arrayLen);
+
+//add an item to the queue, returns false if the queue is full
+bool bytequeue_enqueue(byteQueue_t * queue, uint8_t item);
+
+//get the length of the queue
+byteQueueIndex_t bytequeue_length(byteQueue_t * queue);
+
+//this grabs data at the index given [starting at queue->start]
+uint8_t bytequeue_get(byteQueue_t * queue, byteQueueIndex_t index);
+
+//update the index in the queue to reflect data that has been dealt with 
+void bytequeue_remove(byteQueue_t * queue, byteQueueIndex_t numToRemove);
+
+#ifdef __cplusplus
+}
+#endif 
+
+#endif
+

protocol/lufa/midi/bytequeue/interrupt_setting.c

@@ -0,0 +1,36 @@
+//Copyright 20010 Alex Norman
+//writen by Alex Norman 
+//
+//This file is part of avr-bytequeue.
+//
+//avr-bytequeue 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.
+//
+//avr-bytequeue 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 avr-bytequeue.  If not, see <http://www.gnu.org/licenses/>.
+
+
+//AVR specific code
+//should be able to port to other systems by simply providing chip specific
+//implementations of the typedef and these functions
+
+#include "interrupt_setting.h"
+#include <avr/interrupt.h>
+
+interrupt_setting_t store_and_clear_interrupt(void) {
+   uint8_t sreg = SREG;
+   cli();
+   return sreg;
+}
+
+void restore_interrupt_setting(interrupt_setting_t setting) {
+   SREG = setting;
+}
+

protocol/lufa/midi/bytequeue/interrupt_setting.h

@@ -0,0 +1,39 @@
+//Copyright 20010 Alex Norman
+//writen by Alex Norman 
+//
+//This file is part of avr-bytequeue.
+//
+//avr-bytequeue 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.
+//
+//avr-bytequeue 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 avr-bytequeue.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef INTERRUPT_SETTING_H
+#define INTERRUPT_SETTING_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
+#include <inttypes.h>
+
+//AVR specific typedef
+typedef uint8_t interrupt_setting_t;
+
+interrupt_setting_t store_and_clear_interrupt(void);
+void restore_interrupt_setting(interrupt_setting_t setting);
+
+#ifdef __cplusplus
+}
+#endif 
+
+#endif
+

protocol/lufa/midi/midi_device.h

@@ -0,0 +1,156 @@
+//midi for embedded chips,
+//Copyright 2010 Alex Norman
+//
+//This file is part of avr-midi.
+//
+//avr-midi 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.
+//
+//avr-midi 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 avr-midi.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * @file
+ * @brief Device implementation functions
+ */
+
+#ifndef MIDI_DEVICE_H
+#define MIDI_DEVICE_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
+/**
+ * @defgroup midi_device Functions used when implementing your own 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
+ *
+ * @{
+ */
+
+#include "midi_function_types.h"
+#include "bytequeue/bytequeue.h"
+#define MIDI_INPUT_QUEUE_LENGTH 192
+
+typedef enum {
+   IDLE, 
+   ONE_BYTE_MESSAGE = 1,
+   TWO_BYTE_MESSAGE = 2, 
+   THREE_BYTE_MESSAGE = 3,
+   SYSEX_MESSAGE} input_state_t;
+
+typedef void (* midi_no_byte_func_t)(MidiDevice * device);
+
+/**
+ * \struct _midi_device
+ *
+ * @brief 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.
+ */
+struct _midi_device {
+   //output send function
+   midi_var_byte_func_t send_func;
+
+   //********input callbacks
+   //three byte funcs
+   midi_three_byte_func_t input_cc_callback;
+   midi_three_byte_func_t input_noteon_callback;
+   midi_three_byte_func_t input_noteoff_callback;
+   midi_three_byte_func_t input_aftertouch_callback;
+   midi_three_byte_func_t input_pitchbend_callback;
+   midi_three_byte_func_t input_songposition_callback;
+   //two byte funcs
+   midi_two_byte_func_t input_progchange_callback;
+   midi_two_byte_func_t input_chanpressure_callback;
+   midi_two_byte_func_t input_songselect_callback;
+   midi_two_byte_func_t input_tc_quarterframe_callback;
+   //one byte funcs
+   midi_one_byte_func_t input_realtime_callback;
+   midi_one_byte_func_t input_tunerequest_callback;
+
+   //sysex
+   midi_sysex_func_t input_sysex_callback;
+
+   //only called if more specific callback is not matched
+   midi_var_byte_func_t input_fallthrough_callback;
+   //called if registered, independent of other callbacks
+   midi_var_byte_func_t input_catchall_callback;
+
+   //pre input processing function
+   midi_no_byte_func_t pre_input_process_callback;
+
+   //for internal input processing
+   uint8_t input_buffer[3];
+   input_state_t input_state;
+   uint16_t input_count;
+
+   //for queueing data between the input and the processing functions
+   uint8_t input_queue_data[MIDI_INPUT_QUEUE_LENGTH];
+   byteQueue_t input_queue;
+};
+
+/**
+ * @brief 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.
+ *
+ * @param device the midi device to associate the input with
+ * @param cnt the number of bytes you are processing
+ * @param input the bytes to process
+ */
+void midi_device_input(MidiDevice * device, uint8_t cnt, uint8_t * input);
+
+/**
+ * @brief 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.
+ *
+ * \param device the midi device to associate this callback with
+ * \param send_func the callback function that will do the sending
+ */
+void midi_device_set_send_func(MidiDevice * device, midi_var_byte_func_t send_func);
+
+/**
+ * @brief 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.
+ *
+ * \param device the midi device to associate this callback with
+ * \param midi_no_byte_func_t the actual callback function
+ */
+void midi_device_set_pre_input_process_func(MidiDevice * device, midi_no_byte_func_t pre_process_func);
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif 
+
+#endif

protocol/lufa/midi/midi_function_types.h

@@ -0,0 +1,50 @@
+//midi for embedded chips,
+//Copyright 2010 Alex Norman
+//
+//This file is part of avr-midi.
+//
+//avr-midi 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.
+//
+//avr-midi 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 avr-midi.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * @file
+ * @brief Function signature definitions
+ */
+
+#ifndef MIDI_FUNCTION_TYPES_H
+#define MIDI_FUNCTION_TYPES_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
+#include <inttypes.h>
+#include <stdbool.h>
+
+//forward declaration
+typedef struct _midi_device MidiDevice;
+
+typedef void (* midi_one_byte_func_t)(MidiDevice * device, uint8_t byte);
+typedef void (* midi_two_byte_func_t)(MidiDevice * device, uint8_t byte0, uint8_t byte1);
+typedef void (* midi_three_byte_func_t)(MidiDevice * device, uint8_t byte0, uint8_t byte1, uint8_t byte2);
+//all bytes after count bytes should be ignored
+typedef void (* midi_var_byte_func_t)(MidiDevice * device, uint16_t count, uint8_t byte0, uint8_t byte1, uint8_t byte2);
+
+//the start byte tells you how far into the sysex message you are, the data_length tells you how many bytes data is
+typedef void (* midi_sysex_func_t)(MidiDevice * device, uint16_t start_byte, uint8_t data_length, uint8_t *data);
+
+#ifdef __cplusplus
+}
+#endif 
+
+#endif

protocol/lufa/midi/sysex_tools.c

@@ -0,0 +1,99 @@
+//midi for embedded chips,
+//Copyright 2010 Alex Norman
+//
+//This file is part of avr-midi.
+//
+//avr-midi 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.
+//
+//avr-midi 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 avr-midi.  If not, see <http://www.gnu.org/licenses/>.
+
+#include "sysex_tools.h"
+
+uint16_t sysex_encoded_length(uint16_t decoded_length){
+   uint8_t remainder = decoded_length % 7;
+   if (remainder)
+      return (decoded_length / 7) * 8 + remainder + 1;
+   else
+      return (decoded_length / 7) * 8;
+}
+
+uint16_t sysex_decoded_length(uint16_t encoded_length){
+   uint8_t remainder = encoded_length % 8;
+   if (remainder)
+      return (encoded_length / 8) * 7 + remainder - 1;
+   else
+      return (encoded_length / 8) * 7;
+}
+
+uint16_t sysex_encode(uint8_t *encoded, const uint8_t *source, const uint16_t length){
+   uint16_t encoded_full = length / 7; //number of full 8 byte sections from 7 bytes of input
+   uint16_t i,j;
+
+   //fill out the fully encoded sections
+   for(i = 0; i < encoded_full; i++) {
+      uint16_t encoded_msb_idx = i * 8;
+      uint16_t input_start_idx = i * 7;
+      encoded[encoded_msb_idx] = 0;
+      for(j = 0; j < 7; j++){
+         uint8_t current = source[input_start_idx + j];
+         encoded[encoded_msb_idx] |= (0x80 & current) >> (1 + j);
+         encoded[encoded_msb_idx + 1 + j] = 0x7F & current;
+      }
+   }
+
+   //fill out the rest if there is any more
+   uint8_t remainder = length % 7;
+   if (remainder) {
+      uint16_t encoded_msb_idx = encoded_full * 8;
+      uint16_t input_start_idx = encoded_full * 7;
+      encoded[encoded_msb_idx] = 0;
+      for(j = 0; j < remainder; j++){
+         uint8_t current = source[input_start_idx + j];
+         encoded[encoded_msb_idx] |= (0x80 & current) >> (1 + j);
+         encoded[encoded_msb_idx + 1 + j] = 0x7F & current;
+      }
+      return encoded_msb_idx + remainder + 1;
+   } else {
+      return encoded_full * 8;
+   }
+}
+
+uint16_t sysex_decode(uint8_t *decoded, const uint8_t *source, const uint16_t length){
+   uint16_t decoded_full = length / 8;
+   uint16_t i,j;
+
+   if (length < 2)
+      return 0;
+
+   //fill out the fully encoded sections
+   for(i = 0; i < decoded_full; i++) {
+      uint16_t encoded_msb_idx = i * 8;
+      uint16_t output_start_index = i * 7;
+      for(j = 0; j < 7; j++){
+         decoded[output_start_index + j] = 0x7F & source[encoded_msb_idx + j + 1];
+         decoded[output_start_index + j] |= (0x80 & (source[encoded_msb_idx] << (1 + j)));
+      }
+   }
+   uint8_t remainder = length % 8;
+   if (remainder) {
+      uint16_t encoded_msb_idx = decoded_full * 8;
+      uint16_t output_start_index = decoded_full * 7;
+      for(j = 0; j < (remainder - 1); j++) {
+         decoded[output_start_index + j] = 0x7F & source[encoded_msb_idx + j + 1];
+         decoded[output_start_index + j] |= (0x80 & (source[encoded_msb_idx] << (1 + j)));
+      }
+      return decoded_full * 7 + remainder - 1;
+   } else {
+      return decoded_full * 7;
+   }
+}
+

protocol/lufa/midi/sysex_tools.h

@@ -0,0 +1,95 @@
+//midi for embedded chips,
+//Copyright 2010 Alex Norman
+//
+//This file is part of avr-midi.
+//
+//avr-midi 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.
+//
+//avr-midi 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 avr-midi.  If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef SYSEX_TOOLS_H
+#define SYSEX_TOOLS_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif 
+
+#include <inttypes.h>
+
+/**
+ * @file
+ * @brief Sysex utility functions
+ *
+ * These functions are for converting data to and from a "midi-safe" format,
+ * which can be use to send data with sysex messages.  Sysex messages may only
+ * contain data where the to bit is not set. 
+ *
+ * An "encoded" midi message is one that contains all of the data from its
+ * original state, but does not have any of the top bits set.
+ *
+ * Every 7 bytes of decoded data is converted into 8 bytes of encoded data and
+ * visa-versa.  If you'd like to operate on small segments, make sure that you
+ * encode in 7 byte increments and decode in 8 byte increments.
+ *
+ */
+
+/** @defgroup sysex_tools Sysex utility functions
+ * @{
+ */
+
+/**
+ * @brief Compute the length of a message after it is encoded.
+ *
+ * @param decoded_length The length, in bytes, of the message to encode.
+ *
+ * @return The length, in bytes, of the message after encodeing.
+ */
+uint16_t sysex_encoded_length(uint16_t decoded_length);
+
+/**
+ * @brief Compute the length of a message after it is decoded.
+ *
+ * @param encoded_length The length, in bytes, of the encoded message.
+ *
+ * @return The length, in bytes, of the message after it is decoded.
+ */
+uint16_t sysex_decoded_length(uint16_t encoded_length);
+
+/**
+ * @brief Encode data so that it can be transmitted safely in a sysex message.
+ *
+ * @param encoded The output data buffer, must be at least sysex_encoded_length(length) bytes long.
+ * @param source The input buffer of data to be encoded.
+ * @param length The number of bytes from the input buffer to encode.
+ * 
+ * @return number of bytes encoded.
+ */
+uint16_t sysex_encode(uint8_t *encoded, const uint8_t *source, uint16_t length);
+
+/**
+ * @brief Decode encoded data.
+ *
+ * @param decoded The output data buffer, must be at least sysex_decoded_length(length) bytes long.
+ * @param source The input buffer of data to be decoded.
+ * @param length The number of bytes from the input buffer to decode.
+ * 
+ * @return number of bytes decoded.
+ */
+uint16_t sysex_decode(uint8_t *decoded, const uint8_t *source, uint16_t length);
+
+/**@}*/
+
+#ifdef __cplusplus
+}
+#endif 
+
+#endif