• Make one Arduino Micro send a message "Hello world! Watchout!" and another Arduino Micro receive it using nrf24l01 modules
• Took me two whole days to get this thing up and running
• I used this library: nRF24/nRF24, documentation by tmrh20
• Ignore the TB6612 breakout board

Transmitter Code

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

#define CE_PIN 9
#define CSN_PIN 10
RF24 radio(CE_PIN, CSN_PIN);

const byte ADDRESS[6] = "00001";
const char TEXT[] = "Hello world! Watchout!";

void setup(){
 while (!Serial);
 Serial.begin(9600);
 printf_begin();
 radio.begin();
 //radio.setAutoAck(false);

 radio.setDataRate(RF24_2MBPS);
 //RF24_1MBPS

 radio.setPALevel(RF24_PA_MIN);
 //RF24_PA_LOW

 radio.setRetries(3, 5);
 //delay, count

 radio.openWritingPipe(ADDRESS);
 radio.stopListening();
 radio.printDetails();
}

void loop(){
 radio.write(&TEXT, sizeof(TEXT));
 delay(1000);
}

Receiver Code

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

#define CE_PIN 9
#define CSN_PIN 10

RF24 radio(CE_PIN, CSN_PIN);
const byte ADDRESS[6] = "00001";

void setup() {
  while (!Serial);
  Serial.begin(9600);
  printf_begin();
  radio.begin();
  //radio.setAutoAck(false);

  radio.setDataRate(RF24_2MBPS);
  //RF24_1MBPS

  radio.setPALevel(RF24_PA_MIN);
  //RF24_PA_LOW

  radio.setRetries(3,5);
  //delay, count

  radio.openReadingPipe(0, ADDRESS);
  radio.startListening();

  radio.printDetails();
}

void loop() {
  if (radio.available()) {
    char text[32] = "";
    radio.read(&text, sizeof(text));
    Serial.println(text);
  }
}

Troubleshooting Tips

• Doublecheck all your connection wires, vcc should be connect to 3v, connecting it to 5V will fry your board.

• Be sure to include #include <printf.h> and printf_begin(); to be able to print radio.printDetails() on Serial monitor

• If your nRF24l01 is working properly, you’ll be able to print details with radio.printDetails() of your module in the serial monitor.

  • Pay attention to the Model, Data Rate and PA Power rows.
  • If you set the Data Rate to RF24_2MBPS is should reflect that.
  • If you set PA Power to RF24_PA_LOW it should reflect that.

  

Try these if it’s still not working (I didn’t need them)

• Due to some manufacturers’ poor soldering quality and improper storage, some modules might end up with a grey “crust” over the pins and the underside of the crystal oscillator This crust can affect the conductivity and/or create electrical noise. Remove the crust with a small flat screwdriver or tooth pick and wipe the remaining dust using a dry cloth -Julio Vazquez Vexelius . Instructables
• Solder a 10 uF electrolytic capacitor ground and power. Take note of the polarity. The capacitor is to make sure there is enough power being supplied when it needs it. Without the capacitor it causes unreliable communication.
• Place a capacitor of 100uF between 3.3V and GND of Arduino when using NRF24L01+ because it draws more current than NRF24L01 -The Engineering Projects
• Add radio.setAutoAck(false); after radio.begin() - Vitaliy D
• Watch this video by Ralph S Bacon