I can't receive data with NRF24! [Please help]

Projects Programming
1

Hello, I have:

  • 2 × Arduino Uno
  • 2 × NRF24L01 modules (with antennas)
  • 2 × NRF24-specific adapters (for voltage regulation)

Wiring Setup:

VCC = 5V (using adapters, so VCC is at 5V)
CE → Pin 9
CSN → Pin 10
SCK → Pin 13
MOSI → Pin 11
MISO → Pin 12

(I connected both modules to the Arduinos identically.)

Code Used:

  • Receiver Code:
#include <nRF24L01.h>
#include <RF24.h>

#define CE_PIN   9
#define CSN_PIN  10

RF24 radio(CE_PIN, CSN_PIN);
const byte rxAddr[6] = "00002";

void setup() {
  Serial.begin(9600);
  while(!Serial);
  Serial.println("NRF24L01P Receiver Starting...");

  if (radio.begin()){
    Serial.println("nRF24L01 is started");
  } else {
    Serial.println("nRF24L01 is not started ");
    while (1);
  }

  radio.setPALevel(RF24_PA_LOW);
  radio.setDataRate(RF24_250KBPS);
  radio.openReadingPipe(0, rxAddr);
  radio.startListening();
}

void loop() {
  if (radio.available()) {
    char text[100] = {0};
    radio.read(&text, sizeof(text));
    Serial.println("Received Message: ");
    Serial.print(text);
    Serial.println("");
  } else {
    Serial.println("radio is not available!");
  }
}
  • Transmitter Code:
#include <nRF24L01.h>
#include <RF24.h>

#define CE_PIN 9
#define CSN_PIN 10

RF24 radio(CE_PIN, CSN_PIN);
const byte address[6] = "00002";

void setup() {
  Serial.begin(9600);
  if (radio.begin()) {
    Serial.println("nRF24L01 is started ");
  } else {
    Serial.println("nRF24L01 is not started");
    while (1);
  }

  radio.openWritingPipe(address);
  radio.setPALevel(RF24_PA_HIGH);
  radio.setDataRate(RF24_250KBPS);
  radio.stopListening();
}

void loop() {
  const char text[] = "Selamun aleykum benim adım nodeMCU , nrf24l01 ile bi veriyim.";
  bool result = radio.write(&text, sizeof(text));

  if (result) {
    Serial.println("Mesaj gönderildi: " + String(text));
  } else {
    Serial.println("Mesaj gönderilemedi!");
  }

  delay(1000);
}

Problem:
The transmitter sends signals, but the receiver never gets them.

  • radio.available() always returns false.
  • Tried:
    • External power supply (3.3V regulator).
    • Removing/repositioning antennas.
    • Adding capacitors (10µF–100µF) between GND and VCC.
    • Testing with different Arduinos.
    • Total of 12 hours spent, no progress.

Additional Checks:

  • printDetails() shows no errors (SPI connections correct, addresses match).

PLEASE HELP! :face_with_head_bandage:

2

Perhaps the text you are trying to send exceeds the 32 byte limit of the buffer. Why not serial.Print() the value for the length of the message.

3

have a look at Power Stability Issues with RF24 Radio Modules by @gilshultz

upload a schematic?

4

How is this verified?

Would you post a picture of your transceivers wiring?

5

You should start with code that is well tested and known to work.

This tutorial is a good starting place: Simple nRF24L01+ 2.4GHz transceiver demo

6

Welcome! Without a schematic I have no idea what you have. Good luck!