InterruptButton.ino

InterruptButton.ino

// Teensy 4.1 code to get input from 3 pins and output square wave frequency based on each.

#include <Audio.h>
#include <Wire.h>
#include <SPI.h>
#include <SD.h>
#include <SerialFlash.h>

// GUItool: begin automatically generated code
AudioSynthWaveform       waveform_note;      //xy=433,701
AudioEffectEnvelope      envelope_note;      //xy=628,699
AudioOutputMQS           mqs1;           //xy=830,700
AudioConnection          patchCord1(waveform_note, envelope_note);
AudioConnection          patchCord2(envelope_note, 0, mqs1, 0);
AudioConnection          patchCord3(envelope_note, 0, mqs1, 1);
// GUItool: end automatically generated code



unsigned long last_timestamp_pin20_press = 0;
unsigned long last_timestamp_pin20_release = 0;
bool last_state_pin20 = LOW;

unsigned long last_timestamp_pin17_press = 0;
unsigned long last_timestamp_pin17_release = 0;
bool last_state_pin17 = LOW;

unsigned long last_timestamp_pin14_press = 0;
unsigned long last_timestamp_pin14_release = 0;
bool last_state_pin14 = LOW;

void note_press( int pin ) {

  Serial.print("note_press pin ");
  Serial.println(pin);

  waveform_note.amplitude(0.75);
  waveform_note.frequency(pin * 100);
  envelope_note.noteOn();
}

void note_release( int pin ) {
  
  Serial.print("note_release pin ");
  Serial.println(pin);
  Serial.println("");

  envelope_note.noteOff();
}

void interruptChangePin20() {
  unsigned long timestamp = millis();
  bool pinvalue = digitalRead(20);
  if( last_state_pin20 == HIGH && pinvalue == LOW ) // button release (pin transitions to LOW)
  {
    if( timestamp > last_timestamp_pin20_release + 100 ) //check more than so many milliseconds since last event
    {
      note_release(20);
      last_timestamp_pin20_release = timestamp;
      last_state_pin20 = LOW;
    }
  }
  else if ( last_state_pin20 == LOW && pinvalue == HIGH ) { // button press (pin transitions HIGH)    
    if( timestamp > last_timestamp_pin20_press + 100 ) //check more than so many milliseconds since last event
    { 
      note_press(20);
      last_timestamp_pin20_press = timestamp;
      last_state_pin20 = HIGH;
    }    
  }
}

void interruptChangePin17() {
  unsigned long timestamp = millis();
  bool pinvalue = digitalRead(17);
  if( last_state_pin17 == HIGH && pinvalue == LOW ) // button release (pin transitions to LOW)
  {
    if( timestamp > last_timestamp_pin17_release + 100 ) //check more than so many milliseconds since last event
    {
      note_release(17);
      last_timestamp_pin17_release = timestamp;
      last_state_pin17 = LOW;
    }
  }
  else if ( last_state_pin17 == LOW && pinvalue == HIGH ) { // button press (pin transitions HIGH)    
    if( timestamp > last_timestamp_pin17_press + 100 ) //check more than so many milliseconds since last event
    { 
      note_press(17);
      last_timestamp_pin17_press = timestamp;
      last_state_pin17 = HIGH;
    }    
  }
}

void interruptChangePin14() {
  unsigned long timestamp = millis();
  bool pinvalue = digitalRead(14);
  if( last_state_pin14 == HIGH && pinvalue == LOW ) // button release (pin transitions to LOW)
  {
    if( timestamp > last_timestamp_pin14_release + 100 ) //check more than so many milliseconds since last event
    {
      note_release(14);
      last_timestamp_pin14_release = timestamp;
      last_state_pin14 = LOW;
    }
  }
  else if ( last_state_pin14 == LOW && pinvalue == HIGH ) { // button press (pin transitions HIGH)    
    if( timestamp > last_timestamp_pin14_press + 100 ) //check more than so many milliseconds since last event
    { 
      note_press(14);
      last_timestamp_pin14_press = timestamp;
      last_state_pin14 = HIGH;
    }    
  }
}


void setup() {                
  Serial.begin(38400);

  AudioMemory(10);

  pinMode(20, INPUT_PULLDOWN);
attachInterrupt(digitalPinToInterrupt(20), interruptChangePin20, CHANGE);
  pinMode(17, INPUT_PULLDOWN);
attachInterrupt(digitalPinToInterrupt(17), interruptChangePin17, CHANGE);
  pinMode(14, INPUT_PULLDOWN);
attachInterrupt(digitalPinToInterrupt(14), interruptChangePin14, CHANGE);

  waveform_note.frequency(440);
  waveform_note.amplitude(1.0);
  waveform_note.begin(WAVEFORM_SINE);
}

void loop()                     
{
//  int status=0;
  //  Serial.println(status);
 // delay(2500);
 // status=1;
  //  Serial.println(status);
  delay(100);
  Serial.println("");
}

output DC blocking lowpass filter that only passing bass frequencies with corner freq around 100Hz: