#include <SPI.h>

#define CS 10

void setup() {
  char buffer[] = "Hello World! ";

  Serial.begin(115200);
  pinMode(CS, OUTPUT);

  // SPI Transaction: sends the contents of buffer, and overwrites it with the received data.
  Serial.print("Dado enviado ao dispositivo SPI : ");
  Serial.println(buffer);
  digitalWrite(CS, LOW);
  SPI.begin();
  SPI.transfer(buffer, strlen(buffer));
  SPI.end();
  digitalWrite(CS, HIGH);

  Serial.print("Dado recebido do dispositivo SPI:");
  Serial.println(buffer);
}

void loop() {
}
SPI ExampleBreakout