//SPI Communication

#define CS 10

void SPI_init() {
 
  DDRB |= (1 << PB3) | (1 << PB5) | (1 << PB2); 
  SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR0);
}

char SPI_transfer(char data) {
  SPDR = data;                          
  while (!(SPSR & (1 << SPIF)));        
  return SPDR;                          
}

void setup() {
  char buffer[] = "Uryyb, FCV! ";
  Serial.begin(115200);
  pinMode(CS, OUTPUT);
  digitalWrite(CS, HIGH);
  SPI_init();
  digitalWrite(CS, LOW);
  for (int i = 0; i < strlen(buffer); i++) {
    buffer[i] = SPI_transfer(buffer[i]);
  }
  digitalWrite(CS, HIGH);
  Serial.println("Data received from SPI device:");
  Serial.println(buffer);
}

void loop() {}