Wireless Remote Control with Two NRF24L01 Modules

Build a 2.4GHz radio link between two Arduinos: a joystick transmitter on one end, and a receiver that follows your commands up to 30+ metres away.

What you’ll build

Two NRF24L01 modules form a radio pair. The transmitter Nano streams joystick positions; the receiver Nano turns them into servo motion — the same architecture as an RC car or drone link. Swap the servo for the L298N driver from the robot project and you have a full RC vehicle.

Components you’ll need

Step-by-step guide

1. On both Nanos wire the NRF24L01 over SPI: VCC to 3.3V (never 5V!), GND to GND, CE→D9, CSN→D10, SCK→D13, MOSI→D11, MISO→D12.
2. Solder a 10–100µF capacitor across the module’s VCC/GND if you see random disconnects — these radios are picky about power.
3. Transmitter: wire the joystick to A0/A1 as in the pan-tilt project.
4. Receiver: attach the servo signal to D5.
5. Install the “RF24” library by TMRh20, upload the TX sketch to one Nano and the RX sketch to the other.
6. Power both — the servo should mirror the joystick instantly. Walk away and see how far the link holds.

The code

Both sketches are below — the roles differ only in a few lines. The radio sends a two-int packet 50 times a second.

// ------- TRANSMITTER -------
#include <SPI.h>
#include <RF24.h>
RF24 radio(9, 10);
const byte addr[6] = "ARW01";
int pkt[2];
void setup(){ radio.begin(); radio.openWritingPipe(addr); radio.stopListening(); }
void loop(){
  pkt[0]=analogRead(A0); pkt[1]=analogRead(A1);
  radio.write(&pkt, sizeof(pkt));
  delay(20);
}

// ------- RECEIVER -------
#include <SPI.h>
#include <RF24.h>
#include <Servo.h>
RF24 radio(9, 10); Servo s;
const byte addr[6] = "ARW01";
int pkt[2];
void setup(){
  s.attach(5);
  radio.begin(); radio.openReadingPipe(0, addr); radio.startListening();
}
void loop(){
  if(radio.available()){
    radio.read(&pkt, sizeof(pkt));
    s.write(map(pkt[0], 0, 1023, 0, 180));
  }
}