Hello!
I'm working on build a footswitch MIDI controller for my NUX MG-30 (Guitar effect processor), it's a pretty simple circuit with 3 buttons, 3 leds and a potentiometer that will be controlling the expression pedal,
The code also it's very simple and it's based from this video https://www.youtube.com/watch?v=nh7J71ItDn8&t=9s
/////////////////////////////////////////////
// Choosing your board
// Define your board, choose:
// "ATMEGA328" if using ATmega328 - Uno, Mega, Nano...
// "ATMEGA32U4" if using with ATmega32U4 - Micro, Pro Micro, Leonardo...
// "TEENSY" if using a Teensy board
// "DEBUG" if you just want to debug the code in the serial monitor
// you don't need to comment or uncomment any MIDI library below after you define your board
#define TEENSY 1 //* put here the uC you are using, like in the lines above followed by "1", like "ATMEGA328 1", "DEBUG 1", etc.
/////////////////////////////////////////////
// LIBRARIES
// -- Defines the MIDI library -- //
// if using with ATmega328 - Uno, Mega, Nano...
#ifdef ATMEGA328
#include <MIDI.h> // by Francois Best
MIDI_CREATE_DEFAULT_INSTANCE();
// if using with ATmega32U4 - Micro, Pro Micro, Leonardo...
#elif ATMEGA32U4
#include "MIDIUSB.h"
#endif
// ---- //
/////////////////////////////////////////////
// BUTTONS
const int N_BUTTONS = 3; //* total numbers of buttons
const int BUTTON_ARDUINO_PIN[N_BUTTONS] = {2, 3, 4}; //* pins of each button connected straight to the Arduino
int buttonCState[N_BUTTONS] = {}; // stores the button current value
int buttonPState[N_BUTTONS] = {}; // stores the button previous value
//#define pin13 1 //* uncomment if you are using pin 13 (pin with led), or comment the line if not using
//byte pin13index = 12; //* put the index of the pin 13 of the buttonPin[] array if you are using, if not, comment
// debounce
unsigned long lastDebounceTime[N_BUTTONS] = {0}; // the last time the output pin was toggled
unsigned long debounceDelay = 50; //* the debounce time; increase if the output flickers
/////////////////////////////////////////////
// POTENTIOMETERS
const int N_POTS = 1; //* total numbers of pots (slide & rotary)
const int POT_ARDUINO_PIN[N_POTS] = {A0}; //* pins of each pot connected straight to the Arduino
int potCState[N_POTS] = {0}; // Current state of the pot
int potPState[N_POTS] = {0}; // Previous state of the pot
int potVar = 0; // Difference between the current and previous state of the pot
int midiCState[N_POTS] = {0}; // Current state of the midi value
int midiPState[N_POTS] = {0}; // Previous state of the midi value
const int TIMEOUT = 300; //* Amount of time the potentiometer will be read after it exceeds the varThreshold
const int varThreshold = 10; //* Threshold for the potentiometer signal variation
boolean potMoving = true; // If the potentiometer is moving
unsigned long PTime[N_POTS] = {0}; // Previously stored time
unsigned long timer[N_POTS] = {0}; // Stores the time that has elapsed since the timer was reset
/////////////////////////////////////////////
// LEDS
const int N_LEDS = 3;
const int LED_ARDUINO_PIN[N_LEDS] = {8, 9, 10};
int ledCState[N_LEDS] = {0}; // stores the led current value
int ledPState[N_LEDS] = {0}; // stores the led previous value
/////////////////////////////////////////////
// MIDI
byte midiCh = 0; //* MIDI channel to be used
byte note = 36; //* Lowest note to be used
byte cc = 78; //* Lowest MIDI CC to be used
/////////////////////////////////////////////
// SETUP
void setup() {
// Baud Rate
// use if using with ATmega328 (uno, mega, nano...)
// 31250 for MIDI class compliant | 115200 for Hairless MIDI
//MIDI.begin(MIDI_CHANNEL_OMNI);
Serial.begin(31250);
#ifdef DEBUG
Serial.println("Debug mode");
Serial.println();
#endif
// Buttons
// Initialize buttons with pull up resistors
for (int i = 0; i < N_BUTTONS; i++) {
pinMode(BUTTON_ARDUINO_PIN[i], INPUT_PULLUP);
}
#ifdef pin13 // initialize pin 13 as an input
pinMode(BUTTON_ARDUINO_PIN[pin13index], INPUT);
#endif
}
/////////////////////////////////////////////
// LOOP
void loop() {
buttons();
potentiometers();
}
/////////////////////////////////////////////
// BUTTONS
void buttons() {
for (int i = 0; i < N_BUTTONS; i++) {
buttonCState[i] = digitalRead(BUTTON_ARDUINO_PIN[i]); // read pins from arduino
#ifdef pin13
if (i == pin13index) {
buttonCState[i] = !buttonCState[i]; // inverts the pin 13 because it has a pull down resistor instead of a pull up
}
#endif
if ((millis() - lastDebounceTime[i]) > debounceDelay) {
if (buttonPState[i] != buttonCState[i]) {
lastDebounceTime[i] = millis();
if (buttonCState[i] == LOW) {
digitalWrite(LED_ARDUINO_PIN[i], HIGH);
ledCState[i] = 1;
for(int j = 0; j < N_LEDS; j++){
if(i != j){
digitalWrite(LED_ARDUINO_PIN[j], LOW);
ledCState[j] = 0;
}
}
// Sends the MIDI note ON accordingly to the chosen board
#ifdef ATMEGA328
// use if using with ATmega328 (uno, mega, nano...)
MIDI.sendControlChange(79, i, midiCh); // note, velocity, channel
#elif ATMEGA32U4
// use if using with ATmega32U4 (micro, pro micro, leonardo...)
controlChange(midiCh, 79, i); // channel, note, velocity
MidiUSB.flush();
#elif TEENSY
//do usbMIDI.sendNoteOn if using with Teensy
usbMIDI.sendControlChange(79, i, midiCh); // note, velocity, channel
#elif DEBUG
Serial.print(i);
Serial.println(": button on");
#endif
}
else {
// Sends the MIDI note OFF accordingly to the chosen board
#ifdef ATMEGA328
// use if using with ATmega328 (uno, mega, nano...)
//MIDI.sendNoteOn(79, 0, midiCh + 1); // note, velocity, channel
#elif ATMEGA32U4
// use if using with ATmega32U4 (micro, pro micro, leonardo...)
//noteOn(midiCh, note + i, 0); // channel, note, velocity
MidiUSB.flush();
#elif TEENSY
//do usbMIDI.sendNoteOn if using with Teensy
//usbMIDI.sendNoteOn(note + i, 0, midiCh); // note, velocity, channel
#elif DEBUG
Serial.print(i);
Serial.println(": button off");
#endif
}
buttonPState[i] = buttonCState[i];
ledPState[i] = ledCState[i];
}
}
}
}
/////////////////////////////////////////////
// POTENTIOMETERS
void potentiometers() {
for (int i = 0; i < N_POTS; i++) { // Loops through all the potentiometers
potCState[i] = analogRead(POT_ARDUINO_PIN[i]); // reads the pins from arduino
midiCState[i] = map(potCState[i], 0, 1023, 0, 127); // Maps the reading of the potCState to a value usable in midi
potVar = abs(potCState[i] - potPState[i]); // Calculates the absolute value between the difference between the current and previous state of the pot
if (potVar > varThreshold) { // Opens the gate if the potentiometer variation is greater than the threshold
PTime[i] = millis(); // Stores the previous time
}
timer[i] = millis() - PTime[i]; // Resets the timer 11000 - 11000 = 0ms
if (timer[i] < TIMEOUT) { // If the timer is less than the maximum allowed time it means that the potentiometer is still moving
potMoving = true;
}
else {
potMoving = false;
}
if (potMoving == true) { // If the potentiometer is still moving, send the change control
if (midiPState[i] != midiCState[i]) {
// Sends the MIDI CC accordingly to the chosen board
#ifdef ATMEGA328
// use if using with ATmega328 (uno, mega, nano...)
MIDI.sendControlChange(78, midiCState[i], midiCh); // cc number, cc value, midi channel
#elif ATMEGA32U4
//use if using with ATmega32U4 (micro, pro micro, leonardo...)
controlChange(midiCh, 78, midiCState[i]); // (channel, CC number, CC value)
MidiUSB.flush();
#elif TEENSY
//do usbMIDI.sendControlChange if using with Teensy
usbMIDI.sendControlChange(78, midiCState[i], midiCh); // cc number, cc value, midi channel
#elif DEBUG
Serial.print("Pot: ");
Serial.print(i);
Serial.print(" ");
Serial.println(midiCState[i]);
//Serial.print(" ");
#endif
potPState[i] = potCState[i]; // Stores the current reading of the potentiometer to compare with the next
midiPState[i] = midiCState[i];
}
}
}
}
/////////////////////////////////////////////
// if using with ATmega32U4 (micro, pro micro, leonardo...)
#ifdef ATMEGA32U4
// Arduino (pro)micro midi functions MIDIUSB Library
void noteOn(byte channel, byte pitch, byte velocity) {
midiEventPacket_t noteOn = {0x09, 0x90 | channel, pitch, velocity};
MidiUSB.sendMIDI(noteOn);
}
void noteOff(byte channel, byte pitch, byte velocity) {
midiEventPacket_t noteOff = {0x08, 0x80 | channel, pitch, velocity};
MidiUSB.sendMIDI(noteOff);
}
void controlChange(byte channel, byte control, byte value) {
midiEventPacket_t event = {0x0B, 0xB0 | channel, control, value};
MidiUSB.sendMIDI(event);
}
#endif
My problem is, it works pretty good when in connect the arduino and the pedal to the computer and send the MIDI with a software called PocketMIDI in windows
But once I try to connect arduino to the nux (it has USB type, so I'm using o OTG adaptator), it doens't seems to connect and send data
I'm kind of noob in arduino, i've built some things but nothing too complex, I've used Arduino UNO (Not the clone) with mocolufa, Arduino Leonardo And Teensy2.0 bootloader over Arduino Leonardo without success, And i'm not sure if i need the USB host shield or I'm missing something
thanks in Advance!
English is not my main language, if anything is not clear, I could explain again
