#include <SPI.h>

const byte PIN_CS   =  4;   
#include <EEPROM_SPI_WE.h>
EEPROM_SPI_WE myEEP = EEPROM_SPI_WE(PIN_CS, 999);
#define WREN 6
#define WRDI 4
#define RDSR 5
#define WRSR 1
#define WRITE 2

uint8_t readSReg() {
    uint8_t sreg = 0;
    digitalWrite(PIN_CS, LOW);
    SPI.transfer(RDSR); 
    sreg = SPI.transfer(0x00); 
    digitalWrite(PIN_CS, HIGH);
    return sreg;
}

void setup() {
 
  Serial.begin(115200);
  uint8_t sreg = 0;
  uint8_t ws = 0x80 | 0x0c | 0x02;
  sreg |= ws & 0x8c ;
  Serial.println(sreg);
  //pinMode(PIN_START, INPUT_PULLUP);
  /*if(myEEP.init()){
    Serial.println("EEPROM connected");
  }
  else{
    Serial.println("EEPROM does not respond");
    while(1);
  }*/
   
  pinMode(PIN_CS, OUTPUT);
  
  digitalWrite(PIN_CS, HIGH);
  SPI.begin();
  /*digitalWrite(PIN_CS, LOW);
  SPI.transfer(WREN); 
  digitalWrite(PIN_CS, HIGH);
  Serial.print("SREG: ");
  Serial.println(readSReg());
  return;
  digitalWrite(PIN_CS, LOW);
  SPI.transfer(WRDI); 
  digitalWrite(PIN_CS, HIGH);

  Serial.print("SREG: ");
  Serial.println(readSReg());
  return;*/
  digitalWrite(PIN_CS, LOW);
  SPI.transfer(WREN);
  digitalWrite(PIN_CS, HIGH);

  digitalWrite(PIN_CS, LOW);
  SPI.transfer(WRSR);
  SPI.transfer(0x80);
  digitalWrite(PIN_CS, HIGH);
  // WREN
  digitalWrite(PIN_CS, LOW);
  SPI.transfer(WREN);
  digitalWrite(PIN_CS, HIGH);

  digitalWrite(PIN_CS, LOW);
  SPI.transfer(WRITE);
  //SPI.transfer(32767>>8);
  //SPI.transfer(32767 & 0xff);
  SPI.transfer(63>>8);
  SPI.transfer(63 & 0xff);
  SPI.transfer(100);
  SPI.transfer(110);
  SPI.transfer(120);

  uint16_t addr = 44+64;  // 108
  addr = 257;
  uint16_t p = addr / 64;
  // p è il numero di pagina
  Serial.println(p);
  //p = p * 64;
  uint8_t a = addr - p * 64;
  // a è l'indirizzo del buffer di pagina (0÷63)
  uint16_t startPage = (p * 64);
  Serial.print("startPage: ");
  Serial.println(startPage);
  
  Serial.println(a);
  uint16_t eeadr = startPage + a + 64;
  if (eeadr > startPage + 64) {
      eeadr = startPage;
      
  }
  Serial.print("eeadr: ");
  Serial.println(eeadr);


  digitalWrite(PIN_CS, HIGH);









  /*digitalWrite(PIN_LATCH, LOW);
  SPI.transfer(3);
  SPI.transfer(32767>>8);
  uint8_t v = SPI.transfer(32767 & 0xff);
  v = SPI.transfer(0);
  Serial.println(v);
  v = SPI.transfer(0);
  Serial.println(v);
  v = SPI.transfer(0);
  Serial.println(v);
  digitalWrite(PIN_LATCH, HIGH);*/
  /*delay(1);
  digitalWrite(PIN_CS, LOW);
  SPI.transfer(6);
  digitalWrite(PIN_CS, HIGH);
  delay(1);
  digitalWrite(PIN_CS, LOW);
  SPI.transfer(4);
  digitalWrite(PIN_CS, HIGH);
  delay(1);
  // prova a scrivere
  digitalWrite(PIN_CS, LOW);
  SPI.transfer(2);
  SPI.transfer(32767>>8);
  SPI.transfer(32767 & 0xff);
  SPI.transfer(10);
  SPI.transfer(11);
  SPI.transfer(12);

  digitalWrite(PIN_CS, HIGH);

*/

  
  

}


void loop() { 
    
}