//
// phototransistor input to historical graph
//
// Blair Evans
//
// based on c code by
// Neil Gershenfeld
// 10/27/10
//
// (c) Massachusetts Institute of Technology 2010
// Permission granted for experimental and personal use;
// license for commercial sale available from MIT.
//


const byte photoPin = A5; // Phototransitor

const int led_delay = 1000; // LED delay of 1 ms

/* SV2 */
const byte A = 3; // row 1
const byte B = 4; // row 2
const byte C = 5; // row 3
const byte D = 6; // row 4
const byte E = 7; // row 5

byte anodes1[] = {E,E,E,E,D};
byte anodes2[] = {D,D,D,C,C};
byte anodes3[] = {C,C,B,B,B};
byte anodes4[] = {B,A,A,A,A};
byte cathodes[] = {A,B,C,D,E};

float eps = 1;
float bar1;
float bar2;
float bar3;
float bar4;
int hist[] = {0,0,0,0};
int disp_count = 0;

int photoValue;
byte state = LOW;


void flash(uint8_t from, uint8_t to, uint8_t delay) {
   //
   // source from, sink to, flash
   //
   static int i;
   digitalWrite(from,HIGH); //set(led_port,from);
   digitalWrite(to,LOW); //clear(led_port,to);
   pinMode(from,OUTPUT); //output(led_direction,from);
   pinMode(to,OUTPUT); //output(led_direction,to);
   for (i = 0; i < delay; ++i)
       delayMicroseconds(led_delay);
   pinMode(from,INPUT); //input(led_direction,from);
   pinMode(to,INPUT); // input(led_direction,to);
   }


void setup() {
  Serial.begin(57600); 
  pinMode(13, OUTPUT);
}


void loop() {
  int val;
  int i;
 
     photoValue  = analogRead(photoPin);
     bar4 = (1-eps)*bar4 + eps*photoValue;

     if (state == LOW){
         state = HIGH;
       } else {
         state = LOW;
       }
       digitalWrite(13,state);

      if (disp_count++ >= 5) {
        hist[3] = hist[2];
        hist[2] = hist[1];
        hist[1] = hist[0];
        hist[0] = int((1023-bar4)/256); // 0 to 4 value
        disp_count = 0;
      }
      
      flash(anodes4[hist[0]],cathodes[hist[0]], 4);
      flash(anodes3[hist[1]],cathodes[hist[1]], 4);
      flash(anodes2[hist[2]],cathodes[hist[2]], 4);
      flash(anodes1[hist[3]],cathodes[hist[3]], 4);

/*
      Serial.print(bar1);
      Serial.print(", ");
      Serial.print(bar2);
      Serial.print(", ");
      Serial.print(bar3);
      Serial.print(", ");
      Serial.print(bar4);

      Serial.print("; ");
      Serial.print(hist[0]);
      Serial.print(", ");
      Serial.print(hist[1]);
      Serial.print(", ");
      Serial.print(hist[2]);
      Serial.print(", ");
      Serial.println(hist[3]);
*/
}