ARKeytar - Arduino Based MIDI Controller Keytar

ARKeytar is an expressive Arduino based MIDI controller shaped as a maple wood keytar, with two softpots, a MIDI keyboard and CC controls.

May 11, 2021

•

5607 views

•

4 respects

midi

keytar

controller

Components and supplies

Arduino Nano R3

Potentiometer, Slide

Rotary potentiometer (generic)

Shift Register- Parallel to Serial

SoftPot Membrane Potentiometer - 500mm

Tools and machines

Soldering iron (generic)

Apps and platforms

Arduino IDE

Project description

Code

ARKeytar v5.21

arduino

ARKeytar code version v5.21. Date: 2022-05-01

1/*
2ARKeytar v5.21
32022-05-01, Andrea Gregorini
4*/
5
6
7#include  <MIDI.h>
8MIDI_CREATE_DEFAULT_INSTANCE();
9
10#include <ShiftIn.h>
11ShiftIn<2>  shift;
12
13
14
15
16
17/* panicButton */
18const int panicButton = 2;
19int  panicButtonRead = 0;
20int pressedPanicButton = 0;
21
22
23/* ledPins */
24const  int ledVerde = 3; // Green
25const int ledRosso = 4; // Red
26int ledOnCount =  0;
27
28/* shift register */
29int num;
30int incoming;
31int midiChannel;
32int  ccPot[2] = {0, 1};
33int ccPotOld[2] = {0,0};
34const int listaControlChange[11]  = {7, 74, 71, 11, 1, 5, 73, 91, 93, 72, 10};
35
36/* octave up and octave down  */
37const int up = 6;
38const int down = 5;	        
39
40int transp[2] =  {0, 0};
41int transpSlide[2] = {0, 0};
42int pressedUp = 0;		  int pressedDown  = 0;
43int pressedSlideUp = 0; int pressedSlideDown = 0;
44int transpUp;		        int  transpDown;
45int transpSlideUp;      int transpSlideDown;
46
47
48
49
50/*  rotPot and slidePot */
51int cicliMidiCC[2] = {6, 6};
52int jj[2] = {0, 0};
53
54/*  CC messages variables */
55int ccValue[2];
56int ccRead[2];
57int ccValue_Old[2]  = {0, 0};
58
59
60/* Note range and tuning */
61const int threshold = 998; //  read values discarded above threshold
62
63int lowestNote;             // first  soft pot
64int keyRange;               // number of keys on a single softpot
65      
66int pitchRange;
67int tuning[2];              // semitone shift between  soft pots
68int minNote[2];
69int maxNote[2];
70int octaveShift;
71int semitoneShift;
72
73
74/*  pitch bending */
75int analogPitchRange;
76float intervallo;
77float pitchRangeFloat;
78int  pitchNota[2];
79int pitchSent[2] = {-1,-1};
80int pitchNotaOld[2];
81int pitchPriority  = 0;
82
83/* Pitch stabilization */
84
85int pitchTolerance;
86float DEFAULT_pitchSnap;
87float  pitchSnap;
88int snapOn[2] = {0,0};
89float calcFloat[2];   
90float calcInt[2];   
91float decPart[2];
92
93
94/* A3 = softpot1, A4 = softpot2, A1 = slidepot,  A0 = rotpot */
95const int analogPins[4] = {A3, A4, A1, A0};
96float lettura[2];
97int  letturaInt[2];
98float lettura_Sent[2];
99
100float midiNoteFloat[2];
101int midiNote[2];
102int  midiNote_Sent[2];
103int midiNote_Old[2];
104int sensorPressed[2] = {0, 0};
105
106int  count[2] = {0, 0};
107
108int timePressed[2];
109
110
111/* Pitch values to be applied  when notes are snapped */
112const int range12[25] = 
113{0, 683, 1365, 2048, 2731,  3413, 4096, 4778,
1145461, 6144, 6826, 7509, 8192, 8874, 9557,
11510239, 10922,  11605, 12287, 12970, 13653,
11614335, 15018, 15700, 16383};
117
118const int range24[49]  = 
119{0, 341, 683, 1024, 1365, 1707, 2048, 2389,
1202731, 3072, 3413, 3754, 4096,  4437, 4778,
1215120, 5461, 5802, 6144, 6485, 6826, 7168,
1227509, 7850, 8192, 8533,  8874, 9215, 9557,
1239898, 10239, 10581, 10922, 11263, 11605,
12411946, 12287, 12629,  12970, 13311, 13653,
12513994, 14335, 14676, 15018, 15359, 15700,
12616042, 16383};
127
128
129
130
131
132
133
134
135
136
137
138
139
140void  setup() {
141
142  MIDI.begin(MIDI_CHANNEL_OMNI);
143  Serial.begin(31250);
144
145
146  /* Buttons */
147  pinMode(panicButton, INPUT);
148  pinMode(up, INPUT);
149  pinMode(down,  INPUT);
150
151
152  pinMode(ledVerde, OUTPUT);
153  /* HIGH = led off. LOW = led  on. This is due to the led type used */
154  digitalWrite(ledVerde, HIGH);
155  pinMode(ledRosso,  OUTPUT);
156  digitalWrite(ledRosso, HIGH);
157
158  
159
160  /* Analog ports initialization  */
161  for (int ii = 0; ii <= 1; ii++) {
162     pinMode(analogPins[ii], INPUT_PULLUP);
163  }
164  for (int ii = 2; ii <= 3; ii++) {
165     pinMode(analogPins[ii], INPUT);
166  }
167  
168  /* Read shift registers */
169  shift.begin(8, 9, 11, 12);
170  if(shift.update())  // read in all values. returns true if any button has changed
171  incoming = readShiftReg();
172  saveShiftRegRead(); // Assign incoming values to variables
173
174
175  /* Softpot  settings */
176  lowestNote = 60;
177  keyRange = 32;
178  
179  tuning[0] = 0;
180  tuning[1] = 5;
181  
182  octaveShift = 0;
183  octaveShift = octaveShift*12;
184  semitoneShift = 0;
185
186  /* Apply transopose if read by shift registers or  defined */
187  for (int ii = 0; ii <= 1; ii++) {
188	  minNote[ii] = lowestNote  + tuning[ii] + semitoneShift + octaveShift;
189	  maxNote[ii] = minNote[ii] + keyRange;
190  }
191  
192
193  if (bitRead(incoming,14)== 1) {
194	  pitchRange = 24; //(+-semitones)
195  } else {
196	  pitchRange = 12; //(+-semitones)
197  }
198	
199  pitchTolerance  = (pitchRange-12)/12 * (50-100) + 100;
200  DEFAULT_pitchSnap = 0.2;
201	pitchSnap  = DEFAULT_pitchSnap;
202  intervallo = 16383 / (2*pitchRange);
203  pitchRangeFloat  = float(pitchRange);
204
205
206  analogPitchRange = 1023/(keyRange)*pitchRange;
207
208
209  /* Nothing pressed at the beginning */
210  sensorPressed[0] = 0;
211  sensorPressed[1]  = 0;
212  midiNote_Old[0] = 0;
213  midiNote_Old[1] = 0;
214
215
216}
217
218
219
220
221void  loop() {
222	
223	panic();
224	readPots();
225	transpose();
226	noPressure();
227	newPressure();
228	firstRelease();
229	prolongedRelease();
230	assignPitchPriority();
231	prolongedPressure();
232	potsReadSendCC();
233
234}  
235
236
237
238
239
240int readShiftReg() {
241  for(int i = 0; i < shift.getDataWidth();  i++){
242    bitWrite(num, i, shift.state(i));
243  }
244
245  int incomingNumber  = 0;
246  for (int bitNumber = 8; bitNumber <= 15; bitNumber++) {
247    bitWrite(incoming,  incomingNumber, bitRead(num,bitNumber));
248    incomingNumber++;
249  }
250  for  (int bitNumber = 0; bitNumber <= 7; bitNumber++) {
251    bitWrite(incoming, incomingNumber,  bitRead(num,bitNumber));
252    incomingNumber++;
253  }
254  return incoming;
255}
256
257void  saveShiftRegRead() {
258
259  bitWrite(midiChannel, 0, bitRead(incoming,0));
260  bitWrite(midiChannel, 1, bitRead(incoming,1));
261  bitWrite(midiChannel, 2, bitRead(incoming,2));
262  bitWrite(midiChannel, 3, bitRead(incoming,3));
263
264  bitWrite(ccPot[0], 0,  bitRead(incoming,4));
265  bitWrite(ccPot[0], 1, bitRead(incoming,5));
266  bitWrite(ccPot[0],  2, bitRead(incoming,6));
267  bitWrite(ccPot[0], 3, bitRead(incoming,7));
268
269  bitWrite(ccPot[1], 0, bitRead(incoming,8));
270  bitWrite(ccPot[1], 1, bitRead(incoming,9));
271  bitWrite(ccPot[1], 2, bitRead(incoming,10));
272  bitWrite(ccPot[1], 3, bitRead(incoming,11));
273
274  /*
275  bitRead(incoming,12) Not assigned, unused
276  bitRead(incoming,13) Not  assigned, unused
277  bitRead(incoming,14) used to select pitch range
278  bitRead(incoming,15)  used to select if transpose acts on both softpots or just second one.
279  */
280
281}
282
283void  noteOn(int pitch, int velocity) {
284  Serial.write(144 + midiChannel);        //  Note on command
285  Serial.write(pitch);                    // Note pitch
286  Serial.write(velocity);                 // Note velocity 0-127
287}
288
289void pitchBend(byte lsb, byte  msb) {
290  Serial.write(224 + midiChannel);        // Pitch bend command
291  Serial.write(lsb);                      // Pitch lsb
292  Serial.write(msb);                      //  Pitch msb
293}
294
295void pitchBendMessage(int pitchNota) {
296  int shiftedValue  = pitchNota << 1;
297  byte lsb = lowByte(shiftedValue) >> 1;  // Pitch lsb
298  byte msb = highByte(shiftedValue);      // Pitch msb
299  pitchBend(lsb, msb);
300}
301
302void  midiCC(int CCnumber, int ccValue) {
303  Serial.write(176 + midiChannel);        //  Control change command
304  Serial.write(CCnumber);                 // CC number
305  Serial.write(ccValue);                  // Volume 0-127
306}
307
308void transposeButtonsAction()  {
309  if (transpUp == HIGH && pressedUp == 0) {
310    pressedUp = 1;
311
312    if  (bitRead(incoming, 15) == 0) {
313      transp[0] = transp[0] + 12;
314      transp[1]  = transp[1] + 12;
315    } else if (bitRead(incoming, 15) == 1) {
316      transp[1]  = transp[1] + 12;
317    }
318  }
319
320  if (transpDown == HIGH && pressedDown  == 0) {
321    pressedDown = 1;
322    if (bitRead(incoming, 15) == 0) {
323      transp[0]  = transp[0] - 12;
324      transp[1] = transp[1] - 12;
325    } else if (bitRead(incoming,  15) == 1) {
326      transp[1] = transp[1] - 12;
327    }
328  }
329
330  if (transpUp  == LOW && pressedUp == 1) {
331    pressedUp = 0;
332  }
333
334  if (transpDown  == LOW && pressedDown == 1) {
335    pressedDown = 0;
336  }
337}
338
339void transposeSlideAction()  {
340
341  if (transpSlideUp == HIGH && pressedSlideUp == 0) {
342    pressedSlideUp  = 1;
343
344    if (bitRead(incoming, 15) == 0) {
345      transpSlide[0] = transpSlide[0]  + 12;
346      transpSlide[1] = transpSlide[1] + 12;
347    } else if (bitRead(incoming,  15) == 1) {
348      transpSlide[1] = transpSlide[1] + 12;
349    }
350  }
351
352  if (transpSlideDown == HIGH && pressedSlideDown == 0) {
353    pressedSlideDown  = 1;
354    if (bitRead(incoming, 15) == 0) {
355      transpSlide[0] = transpSlide[0]  - 12;
356      transpSlide[1] = transpSlide[1] - 12;
357    } else if (bitRead(incoming,  15) == 1) {
358      transpSlide[1] = transpSlide[1] - 12;
359    }
360  }
361
362  if (transpSlideUp == LOW && pressedSlideUp == 1) {
363    if (bitRead(incoming,  15) == 0) {
364      transpSlide[0] = transpSlide[0] - 12;
365      transpSlide[1]  = transpSlide[1] - 12;
366    } else if (bitRead(incoming, 15) == 1) {
367      transpSlide[1]  = transpSlide[1] - 12;
368    }
369    pressedSlideUp = 0;
370  }
371
372  if (transpSlideDown  == LOW && pressedSlideDown == 1) {
373    if (bitRead(incoming, 15) == 0) {
374      transpSlide[0] = transpSlide[0] + 12;
375      transpSlide[1] = transpSlide[1]  + 12;
376    } else if (bitRead(incoming, 15) == 1) {
377      transpSlide[1] =  transpSlide[1] + 12;
378    }
379    pressedSlideDown = 0;
380  }
381}
382
383void  ledCtrl(int ledNum) {
384  if (ledNum == 0) {
385    digitalWrite(ledRosso, LOW);
386    ledOnCount = 0;
387  }
388  if (ledNum == 1) {
389    digitalWrite(ledVerde,  LOW);
390    ledOnCount = 0;
391  }
392  if (ledNum > 1 && ledOnCount < 3) {
393    ledOnCount = ledOnCount + 1;
394  }
395  if (ledNum > 1 && ledOnCount >= 3)  {
396    digitalWrite(ledRosso, HIGH);
397    digitalWrite(ledVerde, HIGH);
398    ledOnCount = 0;
399  }
400}
401
402
403
404void panic() {
405
406  panicButtonRead  = digitalRead(panicButton);
407  if (panicButtonRead == HIGH && pressedPanicButton  == 0) {
408
409	  for (int panicChannel = 1; panicChannel <= 16; panicChannel++)  {
410		MIDI.sendControlChange(123,0,panicChannel);
411	  }
412	  pressedPanicButton  = 1;
413  } else {
414	  pressedPanicButton = 0;
415  }
416}
417
418void readPots()  {
419	for (int ii = 0; ii <= 1; ii++) {
420    lettura[ii] = analogRead(analogPins[ii]);
421    lettura[ii] = analogRead(analogPins[ii]);
422	
423      unsigned long timeStart  = micros();
424      while(micros() - timeStart < 5000){
425        MIDI.read();
426      }
427    
428    letturaInt[ii] = int(lettura[ii]);
429
430    midiNoteFloat[ii]  = (lettura[ii]-0)*(maxNote[ii]-minNote[ii])/(1023-0) + minNote[ii];
431    midiNote[ii]  = int(midiNoteFloat[ii]) + transp[ii] + transpSlide[ii];
432  }
433
434  MIDI.read();
435}
436
437void  transpose() {
438  transpUp = digitalRead(up);
439  transpDown = digitalRead(down);
440
441  shift.begin(8, 9, 11, 12);
442  if(shift.update())
443  incoming = readShiftReg();
444
445  transposeButtonsAction();
446  MIDI.read();
447}
448
449void noPressure() {
450	for  (int ii = 0; ii <= 1; ii++) {
451
452    if (letturaInt[ii] >= threshold ) {
453      ledCtrl(23);
454      sensorPressed[ii] = 0;
455      timePressed[ii] = 0;
456    }
457	MIDI.read();
458  }
459}
460
461void newPressure() {
462	for (int ii  = 0; ii <= 1; ii++) {
463    if(letturaInt[ii]<=threshold && sensorPressed[ii]==0  && midiNote[ii]!=midiNote_Old[ii]){
464
465      ledCtrl(1);
466
467      pitchNota[ii]  = 8192;
468      pitchBendMessage(pitchNota[ii]);
469
470      noteOn(midiNote[ii],  0x7F);
471
472      sensorPressed[ii] = 1;
473  	  count[ii] = 1;
474
475      timePressed[ii]  = 1;
476      
477      midiNote_Old[ii] = midiNote[ii];
478      midiNote_Sent[ii]  = midiNote[ii];
479      lettura_Sent[ii] = lettura[ii];
480
481      int kk;
482      if (ii == 0) {kk = 1;} else if (ii == 1) {kk = 0;}
483      
484      if (timePressed[kk]  >= 1 && timePressed[ii] < timePressed[kk]) {
485        pitchPriority = ii + 1;
486      }else if (timePressed[kk] == 0) {
487        pitchPriority = ii + 1;
488      }
489      
490      MIDI.read();
491    }
492  }
493}
494
495void firstRelease() {
496	for  (int ii = 0; ii <= 1; ii++) {
497    if ((letturaInt[ii] >= threshold) && count[ii]  == 1) {
498
499      ledCtrl(0);
500      noteOn(midiNote_Old[ii], 0x00);
501
502      sensorPressed[ii] = 0;
503      midiNote_Old[ii] = midiNote[ii];
504      count[ii]  = count[ii] + 1;
505  
506      MIDI.read();
507    }
508  }
509}
510
511void prolongedRelease()  {
512	for (int ii = 0; ii <= 1; ii++) {
513    if (letturaInt[ii] >= threshold  && count[ii] >=2) {
514      ledCtrl(23);
515      
516      sensorPressed[ii] =  0;
517      count[ii] = 0;
518      timePressed[ii] = 0;
519      
520      MIDI.read();   
521    }
522  }
523}
524
525void assignPitchPriority() {
526
527  if (timePressed[1]  == 0 && sensorPressed[0] == 1 && timePressed[0] >= 0) {
528    pitchPriority = 1;
529  } else if (timePressed[0] == 0 && sensorPressed[1] == 1 && timePressed[1] >= 0)  {
530    pitchPriority = 2;
531  }
532}
533
534void prolongedPressure() {
535	for  (int ii = 0; ii <= 1; ii++) {
536    if (letturaInt[ii] <= threshold && sensorPressed[ii]  == 1 && pitchPriority == ii+1) {
537
538      ledCtrl(23);
539
540      if (lettura[ii]  <= lettura_Sent[ii] - analogPitchRange) {
541        lettura[ii] = lettura_Sent[ii]  - analogPitchRange + 1;
542      }
543      if (lettura[ii] >= lettura_Sent[ii]  + analogPitchRange) {
544        lettura[ii] = lettura_Sent[ii] + analogPitchRange  + 1;
545      }
546
547      pitchNota[ii] = map(lettura[ii], lettura_Sent[ii] -  analogPitchRange,
548                                  lettura_Sent[ii] + analogPitchRange,  0,16383);
549      
550			/* Pitch stabilization */
551      pitchStabilization(ii);
552
553      /* Send stabilized pitch */
554      if (pitchSent[ii] != pitchNota[ii]) {
555        pitchBendMessage(pitchNota[ii]);
556        pitchSent[ii] = pitchNota[ii];
557      }
558      
559      timePressed[ii] = timePressed[ii] + 1;
560      
561      MIDI.read();
562    }
563  }
564}
565
566void pitchStabilization(int iii)  {
567
568      if ((pitchNota[iii] >= 8192 - pitchTolerance) && 
569                                   (pitchNota[iii]  <= 8192 + pitchTolerance)) {
570       pitchNota[iii] = 8192;
571      }
572
573      calcFloat[iii] = pitchNota[iii]/intervallo;
574      calcInt[iii] = (int)calcFloat[iii];
575      decPart[iii] = calcFloat[iii] - calcInt[iii];
576		
577	  /* Snap pitch  towards up (1), and down (2) */
578	  /* (1) */ 
579      if (decPart[iii] <= pitchSnap){
580        snapOn[iii] = 0;
581        if (bitRead(incoming,14) == 0) {
582          pitchNota[iii]  = range12[(int)calcInt[iii]];
583        } else {
584          pitchNota[iii] =  range24[(int)calcInt[iii]];
585        }
586        pitchNotaOld[iii] = pitchNota[iii];
587        
588      } else {
589        snapOn[iii] = snapOn[iii] + 1;
590        if  (snapOn[iii] <= 2 && abs(pitchNota[iii]-pitchNotaOld[iii])> 15) {
591          pitchNota[iii]  = pitchNotaOld[iii];
592        }
593      }
594      
595	  /* (2) */
596      if  (decPart[iii] >= (1 - pitchSnap)){
597        snapOn[iii] = 0;
598        if (bitRead(incoming,14)  == 0) {
599          pitchNota[iii] = range12[(int)calcInt[iii]+1];
600        }  else {
601          pitchNota[iii] = range24[(int)calcInt[iii]+1];
602        }
603        pitchNotaOld[iii] = pitchNota[iii];
604       
605      } else {
606        snapOn[iii]  = snapOn[iii] + 1;
607        if (snapOn[iii] <= 2 && abs(pitchNota[iii]-pitchNotaOld[iii])>  15) {
608          pitchNota[iii] = pitchNotaOld[iii];
609        }
610      }
611
612}
613
614void  potsReadSendCC() {
615	for (int ii = 0; ii <= 1; ii++) { 
616
617		if (ccPot[ii]  == 13) {
618			cicliMidiCC[ii] = 7;
619		} else {
620			cicliMidiCC[ii]  = 7;
621		}
622 
623    if ((jj[ii] % (cicliMidiCC[ii] - ii)) == 0) {
624		if  (ii == 0) {
625			unsigned long timeStart = micros();
626			while(micros()  - timeStart < 4000){
627			  MIDI.read();
628			}
629        }
630      
631      ccRead[ii] = analogRead(analogPins[ii+2]);
632
633      jj[ii] = jj[ii] +  1;
634      if (jj[ii] == cicliMidiCC[ii] - ii) { jj[ii] = 0; }
635      MIDI.read();
636
637      ccValue[ii] = map(ccRead[ii], 0, 1023, 0, 127);
638
639      if (ccValue[ii]  != ccValue_Old[ii] && ccPot[ii] != 12 && ccPot[ii] != 13){
640          midiCC(listaControlChange[ccPot[ii]],  ccValue[ii]);
641      } else if (ccPot[ii] == 12) {
642
643        if (ccRead[ii]  <= 100) {
644            transpSlideDown = HIGH;
645
646        } else if (ccRead[ii]  >= 800) {
647            transpSlideUp = HIGH;
648
649        } else {
650            transpSlideDown  = LOW;
651            transpSlideUp = LOW;
652        }
653          
654        transposeSlideAction();
655      } else if (ccPot[ii] == 13) {
656				/* Control pitch snap with rotPot  */
657				pitchSnap = (ccRead[ii])*0.4/1023 + 0.2;
658				ccPotOld[ii] =  13;
659			}
660      ccValue_Old[ii] = ccValue[ii];
661    } else {
662      jj[ii]  = jj[ii] + 1;
663
664      if (jj[ii] == 2*cicliMidiCC[ii] - ii) { jj[ii] = 0; }
665    }
666		
667		if (ccPotOld[ii] == 13 && ccPot[ii] != 13) {
668			pitchSnap  = DEFAULT_pitchSnap;
669			ccPotOld[ii] = ccPot[ii];
670		}
671		
672	}
673  
674}
675

/*
ARKeytar v5.21
2022-05-01, Andrea Gregorini
*/


#include  <MIDI.h>
MIDI_CREATE_DEFAULT_INSTANCE();

#include <ShiftIn.h>
ShiftIn<2>  shift;





/* panicButton */
const int panicButton = 2;
int  panicButtonRead = 0;
int pressedPanicButton = 0;


/* ledPins */
const  int ledVerde = 3; // Green
const int ledRosso = 4; // Red
int ledOnCount =  0;

/* shift register */
int num;
int incoming;
int midiChannel;
int  ccPot[2] = {0, 1};
int ccPotOld[2] = {0,0};
const int listaControlChange[11]  = {7, 74, 71, 11, 1, 5, 73, 91, 93, 72, 10};

/* octave up and octave down  */
const int up = 6;
const int down = 5;	        

int transp[2] =  {0, 0};
int transpSlide[2] = {0, 0};
int pressedUp = 0;		  int pressedDown  = 0;
int pressedSlideUp = 0; int pressedSlideDown = 0;
int transpUp;		        int  transpDown;
int transpSlideUp;      int transpSlideDown;




/*  rotPot and slidePot */
int cicliMidiCC[2] = {6, 6};
int jj[2] = {0, 0};

/*  CC messages variables */
int ccValue[2];
int ccRead[2];
int ccValue_Old[2]  = {0, 0};


/* Note range and tuning */
const int threshold = 998; //  read values discarded above threshold

int lowestNote;             // first  soft pot
int keyRange;               // number of keys on a single softpot
      
int pitchRange;
int tuning[2];              // semitone shift between  soft pots
int minNote[2];
int maxNote[2];
int octaveShift;
int semitoneShift;


/*  pitch bending */
int analogPitchRange;
float intervallo;
float pitchRangeFloat;
int  pitchNota[2];
int pitchSent[2] = {-1,-1};
int pitchNotaOld[2];
int pitchPriority  = 0;

/* Pitch stabilization */

int pitchTolerance;
float DEFAULT_pitchSnap;
float  pitchSnap;
int snapOn[2] = {0,0};
float calcFloat[2];   
float calcInt[2];   
float decPart[2];


/* A3 = softpot1, A4 = softpot2, A1 = slidepot,  A0 = rotpot */
const int analogPins[4] = {A3, A4, A1, A0};
float lettura[2];
int  letturaInt[2];
float lettura_Sent[2];

float midiNoteFloat[2];
int midiNote[2];
int  midiNote_Sent[2];
int midiNote_Old[2];
int sensorPressed[2] = {0, 0};

int  count[2] = {0, 0};

int timePressed[2];


/* Pitch values to be applied  when notes are snapped */
const int range12[25] = 
{0, 683, 1365, 2048, 2731,  3413, 4096, 4778,
5461, 6144, 6826, 7509, 8192, 8874, 9557,
10239, 10922,  11605, 12287, 12970, 13653,
14335, 15018, 15700, 16383};

const int range24[49]  = 
{0, 341, 683, 1024, 1365, 1707, 2048, 2389,
2731, 3072, 3413, 3754, 4096,  4437, 4778,
5120, 5461, 5802, 6144, 6485, 6826, 7168,
7509, 7850, 8192, 8533,  8874, 9215, 9557,
9898, 10239, 10581, 10922, 11263, 11605,
11946, 12287, 12629,  12970, 13311, 13653,
13994, 14335, 14676, 15018, 15359, 15700,
16042, 16383};













void  setup() {

  MIDI.begin(MIDI_CHANNEL_OMNI);
  Serial.begin(31250);


  /* Buttons */
  pinMode(panicButton, INPUT);
  pinMode(up, INPUT);
  pinMode(down,  INPUT);


  pinMode(ledVerde, OUTPUT);
  /* HIGH = led off. LOW = led  on. This is due to the led type used */
  digitalWrite(ledVerde, HIGH);
  pinMode(ledRosso,  OUTPUT);
  digitalWrite(ledRosso, HIGH);

  

  /* Analog ports initialization  */
  for (int ii = 0; ii <= 1; ii++) {
     pinMode(analogPins[ii], INPUT_PULLUP);
  }
  for (int ii = 2; ii <= 3; ii++) {
     pinMode(analogPins[ii], INPUT);
  }
  
  /* Read shift registers */
  shift.begin(8, 9, 11, 12);
  if(shift.update())  // read in all values. returns true if any button has changed
  incoming = readShiftReg();
  saveShiftRegRead(); // Assign incoming values to variables


  /* Softpot  settings */
  lowestNote = 60;
  keyRange = 32;
  
  tuning[0] = 0;
  tuning[1] = 5;
  
  octaveShift = 0;
  octaveShift = octaveShift*12;
  semitoneShift = 0;

  /* Apply transopose if read by shift registers or  defined */
  for (int ii = 0; ii <= 1; ii++) {
	  minNote[ii] = lowestNote  + tuning[ii] + semitoneShift + octaveShift;
	  maxNote[ii] = minNote[ii] + keyRange;
  }
  

  if (bitRead(incoming,14)== 1) {
	  pitchRange = 24; //(+-semitones)
  } else {
	  pitchRange = 12; //(+-semitones)
  }
	
  pitchTolerance  = (pitchRange-12)/12 * (50-100) + 100;
  DEFAULT_pitchSnap = 0.2;
	pitchSnap  = DEFAULT_pitchSnap;
  intervallo = 16383 / (2*pitchRange);
  pitchRangeFloat  = float(pitchRange);


  analogPitchRange = 1023/(keyRange)*pitchRange;


  /* Nothing pressed at the beginning */
  sensorPressed[0] = 0;
  sensorPressed[1]  = 0;
  midiNote_Old[0] = 0;
  midiNote_Old[1] = 0;


}




void  loop() {
	
	panic();
	readPots();
	transpose();
	noPressure();
	newPressure();
	firstRelease();
	prolongedRelease();
	assignPitchPriority();
	prolongedPressure();
	potsReadSendCC();

}  





int readShiftReg() {
  for(int i = 0; i < shift.getDataWidth();  i++){
    bitWrite(num, i, shift.state(i));
  }

  int incomingNumber  = 0;
  for (int bitNumber = 8; bitNumber <= 15; bitNumber++) {
    bitWrite(incoming,  incomingNumber, bitRead(num,bitNumber));
    incomingNumber++;
  }
  for  (int bitNumber = 0; bitNumber <= 7; bitNumber++) {
    bitWrite(incoming, incomingNumber,  bitRead(num,bitNumber));
    incomingNumber++;
  }
  return incoming;
}

void  saveShiftRegRead() {

  bitWrite(midiChannel, 0, bitRead(incoming,0));
  bitWrite(midiChannel, 1, bitRead(incoming,1));
  bitWrite(midiChannel, 2, bitRead(incoming,2));
  bitWrite(midiChannel, 3, bitRead(incoming,3));

  bitWrite(ccPot[0], 0,  bitRead(incoming,4));
  bitWrite(ccPot[0], 1, bitRead(incoming,5));
  bitWrite(ccPot[0],  2, bitRead(incoming,6));
  bitWrite(ccPot[0], 3, bitRead(incoming,7));

  bitWrite(ccPot[1], 0, bitRead(incoming,8));
  bitWrite(ccPot[1], 1, bitRead(incoming,9));
  bitWrite(ccPot[1], 2, bitRead(incoming,10));
  bitWrite(ccPot[1], 3, bitRead(incoming,11));

  /*
  bitRead(incoming,12) Not assigned, unused
  bitRead(incoming,13) Not  assigned, unused
  bitRead(incoming,14) used to select pitch range
  bitRead(incoming,15)  used to select if transpose acts on both softpots or just second one.
  */

}

void  noteOn(int pitch, int velocity) {
  Serial.write(144 + midiChannel);        //  Note on command
  Serial.write(pitch);                    // Note pitch
  Serial.write(velocity);                 // Note velocity 0-127
}

void pitchBend(byte lsb, byte  msb) {
  Serial.write(224 + midiChannel);        // Pitch bend command
  Serial.write(lsb);                      // Pitch lsb
  Serial.write(msb);                      //  Pitch msb
}

void pitchBendMessage(int pitchNota) {
  int shiftedValue  = pitchNota << 1;
  byte lsb = lowByte(shiftedValue) >> 1;  // Pitch lsb
  byte msb = highByte(shiftedValue);      // Pitch msb
  pitchBend(lsb, msb);
}

void  midiCC(int CCnumber, int ccValue) {
  Serial.write(176 + midiChannel);        //  Control change command
  Serial.write(CCnumber);                 // CC number
  Serial.write(ccValue);                  // Volume 0-127
}

void transposeButtonsAction()  {
  if (transpUp == HIGH && pressedUp == 0) {
    pressedUp = 1;

    if  (bitRead(incoming, 15) == 0) {
      transp[0] = transp[0] + 12;
      transp[1]  = transp[1] + 12;
    } else if (bitRead(incoming, 15) == 1) {
      transp[1]  = transp[1] + 12;
    }
  }

  if (transpDown == HIGH && pressedDown  == 0) {
    pressedDown = 1;
    if (bitRead(incoming, 15) == 0) {
      transp[0]  = transp[0] - 12;
      transp[1] = transp[1] - 12;
    } else if (bitRead(incoming,  15) == 1) {
      transp[1] = transp[1] - 12;
    }
  }

  if (transpUp  == LOW && pressedUp == 1) {
    pressedUp = 0;
  }

  if (transpDown  == LOW && pressedDown == 1) {
    pressedDown = 0;
  }
}

void transposeSlideAction()  {

  if (transpSlideUp == HIGH && pressedSlideUp == 0) {
    pressedSlideUp  = 1;

    if (bitRead(incoming, 15) == 0) {
      transpSlide[0] = transpSlide[0]  + 12;
      transpSlide[1] = transpSlide[1] + 12;
    } else if (bitRead(incoming,  15) == 1) {
      transpSlide[1] = transpSlide[1] + 12;
    }
  }

  if (transpSlideDown == HIGH && pressedSlideDown == 0) {
    pressedSlideDown  = 1;
    if (bitRead(incoming, 15) == 0) {
      transpSlide[0] = transpSlide[0]  - 12;
      transpSlide[1] = transpSlide[1] - 12;
    } else if (bitRead(incoming,  15) == 1) {
      transpSlide[1] = transpSlide[1] - 12;
    }
  }

  if (transpSlideUp == LOW && pressedSlideUp == 1) {
    if (bitRead(incoming,  15) == 0) {
      transpSlide[0] = transpSlide[0] - 12;
      transpSlide[1]  = transpSlide[1] - 12;
    } else if (bitRead(incoming, 15) == 1) {
      transpSlide[1]  = transpSlide[1] - 12;
    }
    pressedSlideUp = 0;
  }

  if (transpSlideDown  == LOW && pressedSlideDown == 1) {
    if (bitRead(incoming, 15) == 0) {
      transpSlide[0] = transpSlide[0] + 12;
      transpSlide[1] = transpSlide[1]  + 12;
    } else if (bitRead(incoming, 15) == 1) {
      transpSlide[1] =  transpSlide[1] + 12;
    }
    pressedSlideDown = 0;
  }
}

void  ledCtrl(int ledNum) {
  if (ledNum == 0) {
    digitalWrite(ledRosso, LOW);
    ledOnCount = 0;
  }
  if (ledNum == 1) {
    digitalWrite(ledVerde,  LOW);
    ledOnCount = 0;
  }
  if (ledNum > 1 && ledOnCount < 3) {
    ledOnCount = ledOnCount + 1;
  }
  if (ledNum > 1 && ledOnCount >= 3)  {
    digitalWrite(ledRosso, HIGH);
    digitalWrite(ledVerde, HIGH);
    ledOnCount = 0;
  }
}



void panic() {

  panicButtonRead  = digitalRead(panicButton);
  if (panicButtonRead == HIGH && pressedPanicButton  == 0) {

	  for (int panicChannel = 1; panicChannel <= 16; panicChannel++)  {
		MIDI.sendControlChange(123,0,panicChannel);
	  }
	  pressedPanicButton  = 1;
  } else {
	  pressedPanicButton = 0;
  }
}

void readPots()  {
	for (int ii = 0; ii <= 1; ii++) {
    lettura[ii] = analogRead(analogPins[ii]);
    lettura[ii] = analogRead(analogPins[ii]);
	
      unsigned long timeStart  = micros();
      while(micros() - timeStart < 5000){
        MIDI.read();
      }
    
    letturaInt[ii] = int(lettura[ii]);

    midiNoteFloat[ii]  = (lettura[ii]-0)*(maxNote[ii]-minNote[ii])/(1023-0) + minNote[ii];
    midiNote[ii]  = int(midiNoteFloat[ii]) + transp[ii] + transpSlide[ii];
  }

  MIDI.read();
}

void  transpose() {
  transpUp = digitalRead(up);
  transpDown = digitalRead(down);

  shift.begin(8, 9, 11, 12);
  if(shift.update())
  incoming = readShiftReg();

  transposeButtonsAction();
  MIDI.read();
}

void noPressure() {
	for  (int ii = 0; ii <= 1; ii++) {

    if (letturaInt[ii] >= threshold ) {
      ledCtrl(23);
      sensorPressed[ii] = 0;
      timePressed[ii] = 0;
    }
	MIDI.read();
  }
}

void newPressure() {
	for (int ii  = 0; ii <= 1; ii++) {
    if(letturaInt[ii]<=threshold && sensorPressed[ii]==0  && midiNote[ii]!=midiNote_Old[ii]){

      ledCtrl(1);

      pitchNota[ii]  = 8192;
      pitchBendMessage(pitchNota[ii]);

      noteOn(midiNote[ii],  0x7F);

      sensorPressed[ii] = 1;
  	  count[ii] = 1;

      timePressed[ii]  = 1;
      
      midiNote_Old[ii] = midiNote[ii];
      midiNote_Sent[ii]  = midiNote[ii];
      lettura_Sent[ii] = lettura[ii];

      int kk;
      if (ii == 0) {kk = 1;} else if (ii == 1) {kk = 0;}
      
      if (timePressed[kk]  >= 1 && timePressed[ii] < timePressed[kk]) {
        pitchPriority = ii + 1;
      }else if (timePressed[kk] == 0) {
        pitchPriority = ii + 1;
      }
      
      MIDI.read();
    }
  }
}

void firstRelease() {
	for  (int ii = 0; ii <= 1; ii++) {
    if ((letturaInt[ii] >= threshold) && count[ii]  == 1) {

      ledCtrl(0);
      noteOn(midiNote_Old[ii], 0x00);

      sensorPressed[ii] = 0;
      midiNote_Old[ii] = midiNote[ii];
      count[ii]  = count[ii] + 1;
  
      MIDI.read();
    }
  }
}

void prolongedRelease()  {
	for (int ii = 0; ii <= 1; ii++) {
    if (letturaInt[ii] >= threshold  && count[ii] >=2) {
      ledCtrl(23);
      
      sensorPressed[ii] =  0;
      count[ii] = 0;
      timePressed[ii] = 0;
      
      MIDI.read();   
    }
  }
}

void assignPitchPriority() {

  if (timePressed[1]  == 0 && sensorPressed[0] == 1 && timePressed[0] >= 0) {
    pitchPriority = 1;
  } else if (timePressed[0] == 0 && sensorPressed[1] == 1 && timePressed[1] >= 0)  {
    pitchPriority = 2;
  }
}

void prolongedPressure() {
	for  (int ii = 0; ii <= 1; ii++) {
    if (letturaInt[ii] <= threshold && sensorPressed[ii]  == 1 && pitchPriority == ii+1) {

      ledCtrl(23);

      if (lettura[ii]  <= lettura_Sent[ii] - analogPitchRange) {
        lettura[ii] = lettura_Sent[ii]  - analogPitchRange + 1;
      }
      if (lettura[ii] >= lettura_Sent[ii]  + analogPitchRange) {
        lettura[ii] = lettura_Sent[ii] + analogPitchRange  + 1;
      }

      pitchNota[ii] = map(lettura[ii], lettura_Sent[ii] -  analogPitchRange,
                                  lettura_Sent[ii] + analogPitchRange,  0,16383);
      
			/* Pitch stabilization */
      pitchStabilization(ii);

      /* Send stabilized pitch */
      if (pitchSent[ii] != pitchNota[ii]) {
        pitchBendMessage(pitchNota[ii]);
        pitchSent[ii] = pitchNota[ii];
      }
      
      timePressed[ii] = timePressed[ii] + 1;
      
      MIDI.read();
    }
  }
}

void pitchStabilization(int iii)  {

      if ((pitchNota[iii] >= 8192 - pitchTolerance) && 
                                   (pitchNota[iii]  <= 8192 + pitchTolerance)) {
       pitchNota[iii] = 8192;
      }

      calcFloat[iii] = pitchNota[iii]/intervallo;
      calcInt[iii] = (int)calcFloat[iii];
      decPart[iii] = calcFloat[iii] - calcInt[iii];
		
	  /* Snap pitch  towards up (1), and down (2) */
	  /* (1) */ 
      if (decPart[iii] <= pitchSnap){
        snapOn[iii] = 0;
        if (bitRead(incoming,14) == 0) {
          pitchNota[iii]  = range12[(int)calcInt[iii]];
        } else {
          pitchNota[iii] =  range24[(int)calcInt[iii]];
        }
        pitchNotaOld[iii] = pitchNota[iii];
        
      } else {
        snapOn[iii] = snapOn[iii] + 1;
        if  (snapOn[iii] <= 2 && abs(pitchNota[iii]-pitchNotaOld[iii])> 15) {
          pitchNota[iii]  = pitchNotaOld[iii];
        }
      }
      
	  /* (2) */
      if  (decPart[iii] >= (1 - pitchSnap)){
        snapOn[iii] = 0;
        if (bitRead(incoming,14)  == 0) {
          pitchNota[iii] = range12[(int)calcInt[iii]+1];
        }  else {
          pitchNota[iii] = range24[(int)calcInt[iii]+1];
        }
        pitchNotaOld[iii] = pitchNota[iii];
       
      } else {
        snapOn[iii]  = snapOn[iii] + 1;
        if (snapOn[iii] <= 2 && abs(pitchNota[iii]-pitchNotaOld[iii])>  15) {
          pitchNota[iii] = pitchNotaOld[iii];
        }
      }

}

void  potsReadSendCC() {
	for (int ii = 0; ii <= 1; ii++) { 

		if (ccPot[ii]  == 13) {
			cicliMidiCC[ii] = 7;
		} else {
			cicliMidiCC[ii]  = 7;
		}
 
    if ((jj[ii] % (cicliMidiCC[ii] - ii)) == 0) {
		if  (ii == 0) {
			unsigned long timeStart = micros();
			while(micros()  - timeStart < 4000){
			  MIDI.read();
			}
        }
      
      ccRead[ii] = analogRead(analogPins[ii+2]);

      jj[ii] = jj[ii] +  1;
      if (jj[ii] == cicliMidiCC[ii] - ii) { jj[ii] = 0; }
      MIDI.read();

      ccValue[ii] = map(ccRead[ii], 0, 1023, 0, 127);

      if (ccValue[ii]  != ccValue_Old[ii] && ccPot[ii] != 12 && ccPot[ii] != 13){
          midiCC(listaControlChange[ccPot[ii]],  ccValue[ii]);
      } else if (ccPot[ii] == 12) {

        if (ccRead[ii]  <= 100) {
            transpSlideDown = HIGH;

        } else if (ccRead[ii]  >= 800) {
            transpSlideUp = HIGH;

        } else {
            transpSlideDown  = LOW;
            transpSlideUp = LOW;
        }
          
        transposeSlideAction();
      } else if (ccPot[ii] == 13) {
				/* Control pitch snap with rotPot  */
				pitchSnap = (ccRead[ii])*0.4/1023 + 0.2;
				ccPotOld[ii] =  13;
			}
      ccValue_Old[ii] = ccValue[ii];
    } else {
      jj[ii]  = jj[ii] + 1;

      if (jj[ii] == 2*cicliMidiCC[ii] - ii) { jj[ii] = 0; }
    }
		
		if (ccPotOld[ii] == 13 && ccPot[ii] != 13) {
			pitchSnap  = DEFAULT_pitchSnap;
			ccPotOld[ii] = ccPot[ii];
		}
		
	}
  
}

Pitch Bend Tables

python

This code computes, for a given pitch range, the pitch bend values corresponding to exact notes for pitch snapping. The code saves these values in a txt file. The content of the output file is ready to be copy-pasted in the Arduino IDE.

1#Python 3.6
2import numpy as np
3
4# Pitch range value, interpreted,  as in synthesizers, as +- number of semitones
5pitchRange = 12
6
7# Generate  the array containing all the pitch bend values corresponding to
8# exact notes  for the given pitch range.
9range12 = np.round(np.arange(-8192, 8192, 16383 /  2 / pitchRange) + 8192)
10
11# Name of the variable containing exact notes pitch  bend value in the
12# Arduino code
13varName = 'range' + str(int(pitchRange))  +\\
14          '[' + str(int(2 * pitchRange + 1)) + ']'
15
16# Name of the txt  file
17fileName = 'pitchValues' + str(int(pitchRange)) + '.txt'
18
19# Write  the txt file with Arduino syntax, ready to be copy-pasted in the
20# IDE
21with  open(fileName, 'w') as f:
22    f.write('const int ' + varName + ' = \
23')
24    f.write('{')
25    for pitchValue in range12[0:-1]:
26        f.write(str(int(pitchValue)))
27        f.write(', ')
28    f.write(str(int(range12[-1])))
29    f.write('};')
30

#Python 3.6
import numpy as np

# Pitch range value, interpreted,  as in synthesizers, as +- number of semitones
pitchRange = 12

# Generate  the array containing all the pitch bend values corresponding to
# exact notes  for the given pitch range.
range12 = np.round(np.arange(-8192, 8192, 16383 /  2 / pitchRange) + 8192)

# Name of the variable containing exact notes pitch  bend value in the
# Arduino code
varName = 'range' + str(int(pitchRange))  +\\
          '[' + str(int(2 * pitchRange + 1)) + ']'

# Name of the txt  file
fileName = 'pitchValues' + str(int(pitchRange)) + '.txt'

# Write  the txt file with Arduino syntax, ready to be copy-pasted in the
# IDE
with  open(fileName, 'w') as f:
    f.write('const int ' + varName + ' = \
')
    f.write('{')
    for pitchValue in range12[0:-1]:
        f.write(str(int(pitchValue)))
        f.write(', ')
    f.write(str(int(range12[-1])))
    f.write('};')

Downloadable files

MIDI in and MIDI out circuits

The switch on the RX port is needed so that the connection to the keyboard is interrupted when new code needs to be uploaded on the Nano, since the serial port is used in such a situation.

MIDI in and MIDI out circuits

Shift registers

The switches are connected to the 8 central pins of each shift register as indicated in the example at the bottom.

Shift registers

Soft pots

Soft pots connections to the analog pins.

Soft pots

Comments

Only logged in users can leave comments

andreagregorini

0 Followers

•

0 Projects

Intro

Trademarks & CopyrightsWhistleblowingDigital Services ActTerms of ServicePrivacy PolicySecurityCookie Settings

Report content