#include <SPI.h>

const int chipSelectPin = 10;        // chip select, the MAX5354 updates output only after chip selct


                                     // is taken high again !

byte highbyte;
byte lowbyte;
byte highbyteVolt[4];                // write the data for SPI
byte lowbyteVolt[4];                 // write the data for SPI
byte highbyteUpdate = B01000000;    // updating DAC output from DAC input register
byte lowbyteUpdate = B00000000;     // updating DAC output from DAC input register

int i = 0;                                    // loop counter

long sineWave = 0;
unsigned long currentTime = 0;
unsigned long currentMicros = 0;
unsigned long previousMicros = 0;
unsigned long periodT = 3000000;        //  21 = 48 kHz    42 = 24 kHz

void setup() {
  pinMode(chipSelectPin, OUTPUT);
  // initialize SPI:
  SPI.begin();
  Serial.begin(9600);


// For the 48 kHz updating rate it is too slow to write data and update on separate commands.
// Control bit C2 C1 C0 for update and D9 to D0 for voltage value
// C2 C1 C0 =
  highbyteVolt[3] = B00011101;       // 3,0 V on 10 bit DAC  (3/3,3)1024 = 11 1010 0011
  lowbyteVolt[3] = B00011000;        // 3,0 V on 10 bit DAC
  highbyteVolt[2] = B00010011;       // 2,0 V on 10 bit DAC  (2/3,3)1024 = 10 0110 1101
  lowbyteVolt[2] = B01101000;        // 2,0 V on 10 bit DAC
  highbyteVolt[1] = B00001001;       // 1,0 V on 10 bit DAC  (1/3,3)1024 = 01 0011 0110
  lowbyteVolt[1] = B10110000;        // 1,0 V on 10 bit DAC
  highbyteVolt[0] = B00000000;       // 0,0 V on 10 bit DAC  (0/3,3)1024 = 00 0000 0000
  lowbyteVolt[0] = B00000000;        // 0,0 V on 10 bit DAC
}

void loop()
{




   currentMicros = micros();

   if(currentMicros - previousMicros > periodT)
   {
    i = i+1;
    if(i == 4)
      {
      i = 0;
      }
   previousMicros = micros();

//Metodi 2
 /*  for(byte i = 0; i < 32++){
      upperByte = i;

      for(int j = 0; j < 256; j++){
        lowerbyte = j << 3;


      }

   }*/

//Metodi 1
 /*  for(uint16_t i = 0; i < 1024; i++){
    uint16_t s = 1*sin(2*PI*1*i+2);

    byte sineUpper = s >> 5;
    byte sineLower = s << 3;

    byte upperbyte = i >> 5;
    byte lowerbyte = i << 3;*/

    int calcPinPoint(int a) {
      return (1024/2)*sin(e*PI/100+512);
    }


    for (int i=0; i< 1024; i++) {
      int value = calcPinPoint(i);
      byte upperByte = value >> 5;
      byte lowerByte = value << 3;


    Serial.print("UpperByte: ");
    Serial.print(upperbyte, BIN);
    Serial.print("\tLowerByte: ");
    Serial.print(lowerbyte, BIN);
    Serial.println();
    //delay(100);
    digitalWrite(chipSelectPin, LOW);
    //SPI.transfer(sineUpper);
    //SPI.transfer(sineLower);
    SPI.transfer(upperbyte);
    SPI.transfer(lowerbyte);
    digitalWrite(chipSelectPin, HIGH);
    delayMicroseconds(2);

    }


    /*
    */

  }

  /* // Write to DAC input register without updating
   // the DAC output register.
   // take the CS pin low to select the chip:
   digitalWrite(chipSelectPin, LOW);
   //  send in the value in two bytes via SPI:
   SPI.transfer(highbyteVolt[i]);
   SPI.transfer(lowbyteVolt[i]);
   // take the CS pin high to de-select the chip:
   digitalWrite(chipSelectPin, HIGH);*/

  /* No need for separate update
   // Update DAC output
   // take the CS pin low to select the chip:
   digitalWrite(chipSelectPin, LOW);
   //  send in the value in two bytes via SPI:
   SPI.transfer(highbyteUpdate);
   SPI.transfer(lowbyteUpdate);
   // take the CS pin high to de-select the chip:
   digitalWrite(chipSelectPin, HIGH);
   */
   }

   //delay(1);   Delay just for debugging if something goes wrong.
}