Code for Master Arduino for SPI Communication

Master_Arduino_for_SPI_Communication.ino

#include <SPI.h>

void setup() {
  Serial.begin(115200); //set baud rate to 115200 for usart
  digitalWrite(SS, HIGH); // disable Slave Select
  SPI.begin();
  SPI.setClockDivider(SPI_CLOCK_DIV8);//divide the clock by 8
}

void loop() {
  char c;
  digitalWrite(SS, LOW); // enable Slave Select
  // send test string
  for (const char * p = "Hello, world!\r" ; c = *p; p++) {
    SPI.transfer (c);
    Serial.print(c);
  }
  digitalWrite(SS, HIGH); // disable Slave Select
  delay(2000);
}