Instrument 3D Schematic
instrument-body.blend

Circuit Diagram
circuit.png

// Preliminary copy of the source code. Not yet feature-complete. ;>

// https://www.arduino.cc/reference/en/libraries/capacitivesensor/
// Arduino CapacitiveSensor. Author: Paul Bagder, Paul Stoffregen
#include <CapacitiveSensor.h>
// https://www.arduino.cc/reference/en/libraries/usb-midi/
// Arduino USB-MIDI Transport. Author: lathoub
#include <USB-MIDI.h>

float peakPitch = 0;
float mappedPitch = 0;
float currPitch = 0;

CapacitiveSensor   cs_9_8 = CapacitiveSensor(3,4); // 1M resistor between pins 4 & 8, pin 8 is sensor pin, add a wire and or foil
//CapacitiveSensor   cs_4_8 = CapacitiveSensor(8,9); // 1M resistor between pins 4 & 8, pin 8 is sensor pin, add a wire and or foil

USBMIDI_CREATE_DEFAULT_INSTANCE();


void setup()                    
{
   Serial.begin(9600);
    MIDI.begin(1);
}

int thresh = 1500;

int currentRead = 0;

int pot0 = 0;
int pot1 = 0;
int pot2 = 0;
int pot3 = 0;

void loop()                    
{

   long sensor1 = 0; 
   long sens2 = 0;

   currentRead += 1;
  
   currPitch += cs_9_8.capacitiveSensor(40);

   if (currentRead >= 4)
   {
      currPitch /= 4;

      Serial.print(currPitch); Serial.print(",");

      if (currPitch > 0) // Get upper part of the frequency spectrum of the pitch input
      {

        if (currPitch > 10000)
          currPitch = peakPitch;
        
        if (currPitch > peakPitch) // Check if the current pitch is higher than the previous
          peakPitch = currPitch; // If it's higher, set the peak at the current pitch

        mappedPitch = map(currPitch, 0, peakPitch, -10, 127); // Maps readings to the appropriate frequency range I want to use. The ADC readings from 550 to 1023 are mapped to frequencies between 5000 and 10Hz. I noticed that the antenna was having constant peaks at 400-500, irrelevant of the objects near it, so I used the map function to get rid of values under 550
      }
      else peakPitch = 0; 

      Serial.print(mappedPitch);
      
      if(mappedPitch > 0)
      {
         if(digitalRead(2) == HIGH)
         {
          MIDI.sendControlChange(3, mappedPitch, 1);
         }
      }
      
      currentRead = 0;
      currPitch = 0;

      Serial.print(",");
      Serial.println(0);
      
   }
   
   if (pot0 <= int(analogRead(A0)/8) - 2 || pot0 >= int(analogRead(A0)/8) + 2)
   {
      MIDI.sendControlChange(10, int(analogRead(A0)/8), 1);
      pot0 = int(analogRead(A0)/8);
   }
   if (pot1 <= int(analogRead(A1)/8) - 2 || pot1 >= int(analogRead(A1)/8) + 2)
   {
      MIDI.sendControlChange(11, int(analogRead(A1)/8), 1);
      pot1 = int(analogRead(A1)/8);
   }
   if (pot2 <= int(analogRead(A2)/8) - 2 || pot2 >= int(analogRead(A2)/8) + 2)
   {
      MIDI.sendControlChange(12, int(analogRead(A2)/8), 1);
      pot2 = int(analogRead(A2)/8);
   }
   if (pot3 <= int(analogRead(A3)/8) - 2 || pot3 >= int(analogRead(A3)/8) + 2)
   {
      MIDI.sendControlChange(13, int(analogRead(A3)/8), 1);
      pot3 = int(analogRead(A3)/8);
   }
     
     
   delay(10);
}