What is NRF24L01?

The NRF24L01 is a 2.4GHz transceiver module that allows your Arduino boards (or robots!) to communicate wirelessly — both sending and receiving data!

It’s ideal for robot-to-robot comms, wireless sensors, remote controllers, and DIY IoT projects.

Key Features

Feature	Description
Frequency	2.4 GHz (ISM band)
Range	~100m (with PA+LNA version)
Data rate	Up to 2 Mbps
Communication	SPI
Voltage	3.3V ONLY ( not 5V-tolerant!)
Multi-device mode	Supports 6 data pipes
Power consumption	Very low (great for batteries)

Needs 3.3V — connecting VCC to 5V will fry it!

Pinout (8 pins)

Pin	Function
GND	Ground
VCC	3.3V power only
CE	Chip Enable
CSN	SPI Chip Select
SCK	SPI Clock
MOSI	SPI Data to module
MISO	SPI Data from module
IRQ	Interrupt (optional)

Wiring with Arduino UNO

Pro tip: Add a 10µF capacitor between VCC and GND to stabilize power (especially if using the PA+LNA long-range version).

Libraries to Use

Install via Arduino IDE Library Manager:

• RF24 by TMRh20 (most popular & well-documented)
• Comes with examples like GettingStarted, pingpair, etc.

Arduino Code Example (Transmitter)

#include <SPI.h>
#include <nRF24L01.h>
#include <RF24.h>

RF24 radio(9, 10); // CE, CSN
const byte address[6] = "00001";

void setup() {
  Serial.begin(9600);
  radio.begin();
  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_LOW);
  radio.stopListening(); // Set as transmitter
}

void loop() {
  const char text[] = "Hello Robot!";
  radio.write(&text, sizeof(text));
  Serial.println("Sent: Hello Robot!");
  delay(1000);
}

Use a second Arduino with the same code, but with radio.startListening() instead — and boom, wireless comms!

Use Cases

• Wireless remote control (joysticks, sliders)
• Robot-to-robot communication
• Sensor networks (e.g., temperature nodes)
• Swarm robotics
• Home automation systems

Tips & Gotchas

3.3V only — use AMS1117 regulator if needed
Power-hungry on transmit — use capacitor
Avoid long jumper wires (can cause instability)
Use separate 3.3V LDO if your Arduino’s regulator is weak

Variants

Version	Features
NRF24L01	Standard ~100m
NRF24L01+PA+LNA	Long-range, with antenna booster
SMD versions	Compact & SMD-friendly