Drumpad.cpp

/*
 Super Easy Diy Drumpad Example
 GIT: https://gist.github.com/billju/ce1337ea3c1dbb4341ce22dca1b55442
 2017 by Billju 
 Inspired by Evan Kale
 */

#include <Keyboard.h>
#include "MIDIUSB.h"

#define NUM_PIEZOS 7
#define NUM_CONTROL 2
#define TIME_BETWEEN_NOTES 50
#define TIME_BETWEEN_PEAKS 20
#define Signal_Fetch 6
#define switch_pin 7
unsigned short noteMap[NUM_PIEZOS]={49,47,45,48,38,44,36}; 
const int slotMap[NUM_PIEZOS]={A0,A1,A2,A3,A4,A5,A11};
const int MAX_velocity[NUM_PIEZOS]= {60,60,60,60,60,60,10};
const int Threshold[NUM_PIEZOS]={6,6,6,6,6,6,1};
int key[NUM_PIEZOS]={'v',216,'c',215,'x','z',13};
bool NoteOn[NUM_PIEZOS];
bool counting[NUM_PIEZOS];
unsigned short NewPeak[NUM_PIEZOS][Signal_Fetch];
unsigned short Peak[NUM_PIEZOS];
unsigned short index[NUM_PIEZOS];
unsigned long lastPeakTime[NUM_PIEZOS];
unsigned long lastNoteTime[NUM_PIEZOS];
unsigned short value[NUM_CONTROL];
unsigned short lastvalue[NUM_CONTROL];
bool switch_state;
void setup()
{
  Serial.begin(115200);

  pinMode(7,INPUT);
 for(short i=0; i<NUM_PIEZOS; ++i){
    NoteOn[i] = 0;
    Peak[i] = 0;
    index[i]= 0;
    counting[i]= 0;
    for(int j=6;j<6;j++){NewPeak[i][j]=0;}
  }
  Keyboard.begin();
}

void loop(){
  switch_state=digitalRead(switch_pin);
  
  for(short i=0; i<NUM_PIEZOS; i++)
  {
    unsigned short newSignal = analogRead(slotMap[i]);
    if(NoteOn[i] == 0){
    if(newSignal > Threshold[i] && counting[i]==0){lastPeakTime[i]=millis();counting[i]=1;}
    else if(newSignal > Threshold[i] && counting[i]==1 && millis()-lastPeakTime[i] < TIME_BETWEEN_PEAKS){
      if(index[i] < Signal_Fetch)
          { NewPeak[i][index[i]]=newSignal;index[i]++;}
    }
    else if(counting[i]==1 && millis()-lastPeakTime[i] > TIME_BETWEEN_PEAKS)
    {   counting[i]=0;
        for(int j=0;j<Signal_Fetch;j++){
          if(NewPeak[i][j] > Peak[i])
            Peak[i]=NewPeak[i][j];
          }
        if(Peak[i]>MAX_velocity[i]){Peak[i]=MAX_velocity[i];}
        int velocity=map(Peak[i],0,MAX_velocity[i],60,127);
        midiNoteOn(noteMap[i], velocity);
        if(switch_state==HIGH)
          Keyboard.press(key[i]);
          
        NoteOn[i]= 1;
        Peak[i]=0;
        index[i]=0;
        for(int j=6;j<6;j++){NewPeak[i][j]=0;}
        lastNoteTime[i]=millis();
      }
    }
      if(NoteOn[i]== 1 && millis() - lastNoteTime[i] > TIME_BETWEEN_NOTES){
        midiNoteOff(noteMap[i], 60);
        if(switch_state==HIGH)
          Keyboard.release(key[i]);

        NoteOn[i]= 0;
      }
      
  }
}
 
void midiNoteOn(byte note, byte midiVelocity){ 
  
  midiEventPacket_t noteOn = {0x09, 0x90 | 0, note, midiVelocity};
  MidiUSB.sendMIDI(noteOn);
  MidiUSB.flush();
  
}

void midiNoteOff(byte note, byte midiVelocity){
  
  midiEventPacket_t noteOff = {0x08, 0x80 | 0, note, midiVelocity};
  MidiUSB.sendMIDI(noteOff);
  MidiUSB.flush();
  
}