VirtualWire demo http://zygzax.com/2013/03/15/comunicacion-entre-arduinos-por-medio-de-radiofrecuencia/

lcdpad.c

#define RS 8
#define EN 9
#define backlight 10
#define RS_L digitalWrite(RS,LOW)
#define RS_H digitalWrite(RS,HIGH)
#define EN_L digitalWrite(EN,LOW)
#define EN_H digitalWrite(EN,HIGH)


// commands
#define LCD_CLEARDISPLAY 0x01
#define LCD_RETURNHOME 0x02
#define LCD_ENTRYMODESET 0x04
#define LCD_DISPLAYCONTROL 0x08
#define LCD_CURSORSHIFT 0x10
#define LCD_FUNCTIONSET 0x20
#define LCD_SETCGRAMADDR 0x40
#define LCD_SETDDRAMADDR 0x80

// flags for display entry mode
#define LCD_ENTRYRIGHT 0x00
#define LCD_ENTRYLEFT 0x02
#define LCD_ENTRYSHIFTINCREMENT 0x01
#define LCD_ENTRYSHIFTDECREMENT 0x00

// flags for display on/off control
#define LCD_DISPLAYON 0x04
#define LCD_DISPLAYOFF 0x00
#define LCD_CURSORON 0x02
#define LCD_CURSOROFF 0x00
#define LCD_BLINKON 0x01
#define LCD_BLINKOFF 0x00

// flags for display/cursor shift
#define LCD_DISPLAYMOVE 0x08
#define LCD_CURSORMOVE 0x00
#define LCD_MOVERIGHT 0x04
#define LCD_MOVELEFT 0x00

// flags for function set
#define LCD_8BITMODE 0x10
#define LCD_4BITMODE 0x00
#define LCD_2LINE 0x08
#define LCD_1LINE 0x00
#define LCD_5x10DOTS 0x04
#define LCD_5x8DOTS 0x00

int DB[] = {7, 6, 5, 4};
/********************************************************************/

void clear()
{
  write_command(LCD_CLEARDISPLAY);  // clear display, set cursor position to zero
  delayMicroseconds(2000);  // this command takes a long time!
}

void write_command(int command) {
  int i, temp;
  RS_L;
  EN_L;
  temp = command & 0xf0;
  for (i = 0; i < 4; i++) {
    if (temp & 0x80) {
      digitalWrite(DB[i], HIGH);
    }
    else {
      digitalWrite(DB[i], LOW);
    }
    temp <<= 1;
  }
  EN_H;
  delayMicroseconds(1000);
  EN_L;
  temp = (command & 0x0f) << 4;
  for (i = 0; i < 4; i++) {
    if (temp & 0x80) {
      digitalWrite(DB[i], HIGH);
    }
    else {
      digitalWrite(DB[i], LOW);
    }
    temp <<= 1;
  }
  EN_H;
  delayMicroseconds(1000);
  EN_L;
}

/********************************************************************/
void write_data(int dat) {
  int i = 0, temp;
  RS_H;
  EN_L;
  temp = dat & 0xf0;
  for (i = 0; i < 4; i++) {
    if (temp & 0x80) {
      digitalWrite(DB[i], HIGH);
    }
    else {
      digitalWrite(DB[i], LOW);
    }
    temp <<= 1;
  }
  EN_H;
  delayMicroseconds(1000);
  EN_L;
  temp = (dat & 0x0f) << 4;
  for (i = 0; i < 4; i++) {
    if (temp & 0x80) {
      digitalWrite(DB[i], HIGH);
    }
    else {
      digitalWrite(DB[i], LOW);
    }
    temp <<= 1;

  }
  EN_H;
  delayMicroseconds(1000);
  EN_L;
}
/********************************************************************/
void LCD_write_char( int x, int y, int dat) {
  int address;
  if (x == 0) {
    address = 0x80 + y;
  }
  else {
    address = 0xC0 + y;
  }
  write_command(address);
  write_data(dat);
  delayMicroseconds(1000);
}
/********************************************************************/
void lcd1602_init() {
  int i = 0;
  pinMode(RS, OUTPUT);
  pinMode(EN, OUTPUT);
  pinMode(backlight, OUTPUT);
  digitalWrite(backlight, HIGH);
  for (i = 0; i < 4; i++) {
    pinMode(DB[i], OUTPUT);
  }
//  delayMicroseconds(50000);
  digitalWrite(RS, LOW);
  digitalWrite(EN, LOW);
  delayMicroseconds(100);
  write_command(0x28);
  delay(50);
  write_command(0x06);
  delay(50);
  write_command(0x0c);
  delay(50);
  write_command(0x80);
  delay(50);
  write_command(0x01);
  delay(100);
}
/********************************************************************/
void setup (void) {
  lcd1602_init();
  clear();
  delay(500);
}
/********************************************************************/
void loop (void) {
  clear();
  LCD_write_char(0, 4, 'H');
  LCD_write_char(0, 5, 'e');
  LCD_write_char(0, 6, 'l');
  LCD_write_char(0, 7, 'l');
  LCD_write_char(0, 8, 'o');
  LCD_write_char(0, 9, 'w');
  LCD_write_char(1, 4, 'w');
  LCD_write_char(1, 5, 'o');
  LCD_write_char(1, 6, 'r');
  LCD_write_char(1, 7, 'l');
  LCD_write_char(1, 8, 'd');
  delay(500);
}

receiver.c

//Test and text transmission with RF module for Arduino http://zygzax.com
//RECEIVER
#include <VirtualWire.h>
 
void setup()
{
  Serial.begin(9600);          // Configure the serial connection to the computer
  vw_set_ptt_inverted(true);  // Required by the RF module
  vw_setup(2000);            // bps connection speed
  vw_set_rx_pin(3);         // Arduino pin to connect the receiver data pin
  vw_rx_start();           // Start the receiver
}
 
void loop()
{
  uint8_t buf[VW_MAX_MESSAGE_LEN];
  uint8_t buflen = VW_MAX_MESSAGE_LEN;
  if (vw_get_message(buf, &buflen))      // We check if we have received data
  {
    int i;
    // Message with proper check    
    for (i = 0; i < buflen; i++)
    {
      Serial.write(buf[i]);  // The received data is stored in the buffer
                            // and sent through the serial port to the computer
    }
    Serial.println();
  }
}

transmitter.c

//Test and text transmission with RF module for Arduino http://zygzax.com
//TRANSMITTER
#include <VirtualWire.h>
void setup()
{
  vw_set_ptt_inverted(true);  // Required by the RF module
  vw_setup(2000);            // bps connection speed
  vw_set_tx_pin(3);         // Arduino pin to connect the receiver data pin
}
 
void loop()
{
  //Message to send:
  const char *msg = "HELLO WORLD";
  vw_send((uint8_t *)msg, strlen(msg));
  vw_wait_tx();        // We wait to finish sending the message
  delay(200);         // We wait to send the message again                
}