//1ch waveform sampler sketch

//FASTADC set to 1 ups the sampling rate to 77kHz
//Found this on the Arduino Forum here http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1208715493/11 - Thanks to jmknapp

#define FASTADC 0

// defines for setting and clearing register bits
#ifndef cbi
#define cbi(sfr, bit) (_SFR_BYTE(sfr) &= ~_BV(bit))
#endif
#ifndef sbi
#define sbi(sfr, bit) (_SFR_BYTE(sfr) |= _BV(bit))
#endif

//variable used to signal when we are to take a sample.
int getSample;

//360 locations is about the maximum on the memory of my Arduino
int aval[360];

//Used to measure the length in time of the sample
unsigned long t1,t2,t3;

//stores the byte sent by the program when the button sample is pressed
int incomingByte = 0;


void setup()
{
  
//ADC sample rate code
  #if FASTADC
//set prescale to 16
sbi(ADCSRA,ADPS2) ;
cbi(ADCSRA,ADPS1) ;
cbi(ADCSRA,ADPS0) ;
#endif


Serial.begin(115200);
  
}

void loop()
{ 
  
   //Check if the java program has sent the command to start sampling
   if (Serial.available()>0) 
   {
      incomingByte = Serial.read(); 
      getSample = 1;   
   }
   
   //If were ok to go with sampling...
   if (getSample == 1)
   { 
      getSample =0;
     
      //Wait until the waveform is near the 0 line. 
      //int raw=analogRead(0)-512;
      //while (raw<-10 || raw>10) raw=analogRead(1)-512;

      //Take the time at the start
      t1=millis();
      
      //Take 360 samples
      for(int i=0; i<360; i++)
      {
         aval[i]=analogRead(0);
      }
      
      //Take end time
      t2=millis();
   
      //Calculate overall time
      t3=t2-t1;
 
      //Send the time taken first so that java program can set time intervals 
      //between each sample.    
      Serial.print(t3);
      Serial.print("C");
      
      //Send sampled data in one lump.
      for(int i=0; i<360; i++)
      {
         Serial.print(aval[i]);
         Serial.print("A");
      }

   }

}