Final MidI Instrument

Solfege Gesture MIDI

CODE

Since last week, I added a flex sensor. This allowed me to map more specific data to each gesture. I also added MIDI code so that notes could be sent over serial to Garage Band. It is still quite finicky, but I had enough resolution to play a simple scale and even notes in different orders.

#include <Arduino_LSM6DS3.h>
#include <MIDIUSB.h>

#define FLEXPORT 14
#define ALPHA 0.5
float roll, pitch, ax, ay, az;
float fx, fy, fz;
int flexed;

byte Do = 60;
byte Re = 62;
byte Mi = 64;
byte Fa = 65;
byte So = 67;
byte La = 69;
byte Ti = 71;

byte prevNote;

void setup() {
 //begin receiving IMU data
 Serial.begin(9600);
  IMU.begin();
}

void loop() {
  flexed = map(analogRead(FLEXPORT), 750, 930, 0, 100);
  //Serial.println(flexed);
    //read IMU data
  IMU.readAcceleration(ax, ay, az);
  //Convert to sensor fusion values
  fx = ax * ALPHA + (fx * (1.0 - ALPHA));
  fy = ay * ALPHA + (fy * (1.0 - ALPHA));
  fz = az * ALPHA + (fz * (1.0 - ALPHA));
  
  //equations for roll & pitch
  roll = (atan2(-fy, fz)*180.0)/M_PI;
  pitch = (atan2(fx, sqrt(fy*fy + fz*fz))*180.0)/M_PI;
  midiEventPacket_t sound;
  byte note = 0;
  byte cmd = 0x90;
  Serial.print("PITCH: ");
  Serial.print(pitch);
  Serial.print(" | ROLL: ");
  Serial.print(roll);
  Serial.print(" | FLEXED: ");
  Serial.print(flexed);
  Serial.print(" | ");

  //map pitch & roll data to solfege notes
  if(abs(roll) <= 10 && abs(pitch) <= 10 && flexed > 75){
    //Do, MIDI 72
    note = Do;
    Serial.println("Do");
  }

  if(abs(roll) >= 0 && abs(roll)<= 10 && pitch <= -15 && pitch >= -45 && flexed < 10){
    //Re, MIDI 74
    note = Re;
    Serial.println("Re");
  }

  if(abs(roll) <= 10 && abs(pitch) <= 10 && flexed < 10){
    //Mi, MIDI 76
    note = Mi;
    Serial.println("Mi");
  }

  if(roll >= -65 && roll <= -45 && pitch <= 3 && pitch >= -25 && flexed > 75){
    //Fa, MIDI 77
    note = Fa;
    Serial.println("Fa");
  }

  if(roll >= 55 && roll <= 65 && pitch <= 0 && pitch >= -10 && flexed < 10){
  //So, MIDI 79
  note = So;
   Serial.println("So");
  }

  if(abs(roll) <= 10 && abs(pitch) <= 10 && flexed > 20 && flexed < 70){
    //La, MIDI 81
    note = La;
    Serial.println("La");
  }

    if(abs(roll) >= 0 && abs(roll)<= 17 && pitch <= -35 && pitch >= -40 && flexed > 40){
    //Re, MIDI 74
    note = Ti;
    Serial.println("Ti");
  }

  if(!note){
    cmd = 0x80;
    note = 0x00;
  }
  if(note != prevNote){
   sound = {cmd >> 4, cmd | 0, note, 0x45};
   MidiUSB.sendMIDI(sound);
   delay(100);
  }
  if(note){
    prevNote = note;
  }
Serial.println();
}

FABRICATION

This was the ultimate at-home fab job. I used duct tape (of a galaxy variety) and velcro. It’s not the prettiest thing to look at but it does kinda feel bionic and the duct tape is surprisingly comfortable.

DEMO