Transmitter Code:

// 3 Channel Transmitter
  #include <SPI.h>
  #include <nRF24L01.h>
  #include <RF24.h>
  const uint64_t pipeOut = 0xE9E8F0F0E1LL;   // Match key
  RF24 radio(9, 10);                         // Select CE,CSN pin
  struct Signal {
  byte throttle;
  byte steering;
  byte aux1;

};
  Signal data;
  void ResetData() 
{
  data.throttle = 127;     // Motor stop (Signal lost position)
  data.steering = 127;    //  Center (Signal lost position)
  data.aux1 = 0;          //  (Signal lost position)

}
  void setup()
{
  //Start everything up
  radio.begin();
  radio.openWritingPipe(pipeOut);
  radio.setAutoAck(false);
  radio.setDataRate(RF24_250KBPS);
  radio.setPALevel(RF24_PA_MAX);
  radio.stopListening();             //start the radio comunication for Receiver
  ResetData();
 
}
  // Joystick center and it's borders
  int mapJoystickValues(int val, int lower, int middle, int upper, bool reverse)
{
  val = constrain(val, lower, upper);
  if ( val < middle )
  val = map(val, lower, middle, 0, 128);
  else
  val = map(val, middle, upper, 128, 255);
  return ( reverse ? 255 - val : val );
}
  void loop()
{
  // Control Stick Calibration
  // Setting may be required for the correct values of the control levers.
  
  data.steering = mapJoystickValues( analogRead(A0), 200, 460, 650, true );    // "true" or "false" for servo direction
  data.throttle = mapJoystickValues( analogRead(A1), 200, 440,670, true );    // "true" or "false" for signal direction
  data.aux1 = digitalRead(4); 
  radio.write(&data, sizeof(Signal));
}