Add udev rule - triggered when Arduino Uno is connected

85-arduino.rules

#Rule to run script when Arduino Uno is connected
KERNEL=="ttyACM0",ACTION=="add",RUN+="/path/to/script"

buttonListener.ino

// Six button arduino MIDI device
#include <midi_Settings.h>
#include <midi_Defs.h>
#include <midi_Message.h>
#include <midi_Namespace.h>
#include <MIDI.h>
 
int buttonStates[6];
int defaultStates[6];
//send notes on this channel:
MIDI_CREATE_DEFAULT_INSTANCE();
int MIDIChannel = 10;


void setup(){
  //start serial connection  
  //configure pin2 as an input and enable the internal pull-up resistor
  for(int i = 0; i < 6; i++){
   pinMode(i+2, INPUT_PULLUP); 
  }
  pinMode(13, OUTPUT); 
  for(int i = 0; i < 6; i++){
   buttonStates[i] = defaultStates[i] = digitalRead(i+2);
  }
  MIDI.begin(4);
  Serial.begin(115200);
}

void loop(){
  //read the pushbutton value into a variable
  int sensorValues[6];
  for(int i = 0; i < 6; i++){
     sensorValues[i] = digitalRead(i+2);
    
    if(buttonStates[i] != sensorValues[i]){
     if(sensorValues[i] != defaultStates[i]){
       //Serial.print("button ");
       //Serial.print(i);
       //Serial.println(" ON");
       MIDI.sendNoteOn(i,127, MIDIChannel);
     }
     else{
       //Serial.print("button ");
       //Serial.print(i);
       //Serial.println(" OFF");
       MIDI.sendNoteOff(i, 0, MIDIChannel);
     }
    }
    buttonStates[i] = sensorValues[i];
  }
  // Keep in mind the pullup means the pushbutton's
  // logic is inverted. It goes HIGH when it's open,
  // and LOW when it's pressed. Turn on pin 13 when the 
  // button's pressed, and off when it's not:
  if (sensorValues[0] == HIGH) {
    digitalWrite(13, LOW);
  } 
  else {
    digitalWrite(13, HIGH);
  }
}

gistfile1.txt

#prints device info about arduino uno
udevadm info -a -p $(udevadm info -q path -n /dev/ttyACM0) | less

ttymidiScript.sh

#!/bin/sh
#connects arduino Uno as a MIDI device
ttymidi -s /dev/ttyACM0