LiquidAnimation.c

/* 
 * Arduino control for a solenoid valve array (currently 8 pieces), which are hooked up to tubes with liquid inside.
 * Each solenoid valve controls a stream of air which is blown into the stream of liquid inside the tubes.
 * By layouting the tubes on a wall it's possible to create beautiful animations
 */
 
#define TRACK_NUMBER 8
#define MAX_CHARS_PER_TRACK 80

class Track 
{

private:
  unsigned long lastUpdate=0;
  int step = 0;
  int pin;
  float speed = 30;
  int notesPerBeat;
  const char* pattern;
  
public:
  Track(){
    Serial.println("init new empty track");
  }

  // speed: bpm / 16
  void loadPattern(const char* pattern) {
    this->pattern = pattern;
    
    this->notesPerBeat = strlen(pattern);
    
    Serial.print("load pattern pin");
    Serial.print(this->pin);
    Serial.print(": ");
    Serial.print(this->pattern);
    Serial.print("size: ");
    Serial.println(this->notesPerBeat);
  
  }

  long getLastUpdate(){
      return lastUpdate;
  }
  void setSpeed(int speed) {
    this->speed = speed;  
  }
  void setPin(int pin) {
    this->pin = pin;  
  }

  const char * getPattern(){
    return this->pattern;
  }
  void update(){
    int timePerStep = (int) (10000.0 / (float) speed);
    if(this->lastUpdate + timePerStep < millis()){
      char onOff = pattern[step];
      if(onOff == 'x'){
        digitalWrite(pin, HIGH);
      }else{
        if(pin == 4 || pin == 11){
          Serial.print(step);
          Serial.print("th step ");
          Serial.print(pin);
          Serial.print(" off  ");
          Serial.print(" onOff:");
          //Serial.println((int) onOff);
          
        }
        digitalWrite(pin, LOW);
      }
      lastUpdate = millis();
      step++;
      if(step >= notesPerBeat){
        step = 0;
      }
    }
  }
};

class Sequencer {
  Track tracks[TRACK_NUMBER];
  
public:
  Sequencer(){}
  
  void init(int pins[], int speed){
    for(int i=0;i<TRACK_NUMBER;i++){
      int pin = pins[i];
      Serial.print("create new track on pin ");
      Serial.println(pin);
      //this->tracks[i] = Track(pin);
      tracks[i].setPin(pin);
      tracks[i].setSpeed(speed);
    }
  }

  void loadPattern(const char pattern[][MAX_CHARS_PER_TRACK]){
    for(int i=0;i<TRACK_NUMBER;i++) {
      tracks[i].loadPattern(pattern[i]);
    }
  }

  Track getTrack(int pos){
    return tracks[pos];  
  }
  void setSpeed(int speed){
    for(int i=0;i<TRACK_NUMBER;i++) {
      tracks[i].setSpeed(speed);
    }
  }

  void update(){
    for(int i=0;i<TRACK_NUMBER;i++) {
      tracks[i].update();
    }
  }
};

Sequencer sequencer;


void setup() {
  Serial.begin(9600);
  int pins[] = {11, 10, 9, 8, 7, 6, 5, 4};
  

   const char pattern2[TRACK_NUMBER][MAX_CHARS_PER_TRACK] = 
                      {"   xxxx      xxxx   xx   x       x              ",
                       "                         x       x              ",
                       "                         x       x              ",
                       "                         x       x              ",
                       "                         x       x              ",
                       "                         x       x              ",
                       "                         x       x              ",
                       "   xxxx      xxxx   xx   x       x              ",
                       };
  
    
  sequencer.init(pins, 120);
  sequencer.loadPattern(pattern2);

  Serial.println("pattern after setup (still OK): ");
  Serial.println(sequencer.getTrack(7).getPattern());
}

void loop() {
  
  Serial.println("pattern before update (still ok): ");
  Serial.println(sequencer.getTrack(7).getPattern()); // <-- prints "   xxxx      xxxx   xx   x       x              "
  sequencer.update(); // <-- this is where some memory issue is happening, screwing up the pattern2 var
  
  Serial.println("pattern after update (messed up): ");
  Serial.println(sequencer.getTrack(7).getPattern()); // <-- prints "   xxxx      xx���4"
}