int optoPin = 10;
int optoValue = 0;
int emgValue = 0;
int emgPin = 0;

int emgArray [100];
int emgDif;
int emgLength = 100;

// minimum and maximum values for mapping emg signals

int minThresh;
int maxThresh;

/*
  unused code, possible use later to smooth out the signal
int optoRange[100];
float averager = 0;
*/

int temp;

 void setup()
 {
   // start serial port at 9600 bps:
   Serial.begin(9600);
   
   pinMode(optoPin, OUTPUT);
   
   minThresh = 3;
   maxThresh = 12;
   
 }


 void loop()
 {

   for (int i = 0; i < emgLength; ++i)
   {
     emgValue = analogRead(emgPin);
     emgArray[i] = emgValue;     
 
 
  /*
    possilbe future code for smoothing things out
    
     optoRange[i] = optoValue;
     
     if (i < emgLength - 1)
     {   
       optoRange[i+1] = optoRange[i];
     }
     
   */
   
   }
   
   
   /*
     possible future code for later
   
   for (int j = 0; j < emgLength; ++j)
   {
     averager = averager + optoRange[j];
   }
   
   averager = averager / 100;
   */
 
   temp = emgArray[emgLength-1] - emgArray[0];
   emgDif = abs(temp);
      
   if (emgDif > maxThresh)
   {
      emgDif = maxThresh;
   }
   
   if (emgDif < minThresh)
   {
     emgDif = minThresh;
   }

    Serial.print(minThresh);
    Serial.print('\t');
    Serial.print(maxThresh);
    Serial.print('\t');
     
    optoValue = map(emgDif, minThresh, maxThresh, 0, 255);  // maps emg to optoisolator


    analogWrite(optoPin, optoValue);
  
     
   Serial.print(emgValue, DEC);
   Serial.print('\t');                  // print a tab
   Serial.print(emgDif);      // print the ASCII encoded hexadecimal analogValue
   Serial.print('\t');                  // print a tab
   Serial.print(emgArray[0]);      // print the ASCII encoded octal analogValue
   Serial.print('\t');
   Serial.print(optoValue);  
   Serial.println();