#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>
#define CE_PIN 4
#define CSN_PIN 2
const uint64_t pipe = 0xE8E8F0F0E1LL; // address 
RF24 radio(CE_PIN, CSN_PIN);
char data[] = "Message from Master to slave";
void setup()
{
  Serial.begin(9600);
  radio.begin();
  radio.openWritingPipe(pipe);
}

void loop()
{
  radio.write( data, sizeof(data) );
}