README.md

nRF24L01 - Single Chip 2.4 GHz Transceiver

The nRF24L01 is a single chip radio transceiver for the world wide 2.4 - 2.5 GHz ISM band.

Documentation

• The bindging datasheet can be found here

Board

Usage

Hardware Required

• nRF24L01 × 2
• Male/Female Jumper Wires

Connection for nRF1

• VCC - 3.3V (Best)
• GND - GND
• MOSI - SPI0 MOSI (GPIO 10)
• MISO - SPI0 MISO (GPIO 9)
• SCK - SPI0 SCLK (GPIO 11)
• CSN - SPI0 CS0 (GPIO 8)
• CE - GPIO 23
• IRQ - GPIO 24

Connection for nRF2

• VCC - 3.3V (Best)
• GND - GND
• MOSI - SPI1 MOSI (GPIO 20)
• MISO - SPI1 MISO (GPIO 19)
• SCK - SPI1 SCLK (GPIO 21)
• CSN - SPI1 CS0 (GPIO 16)
• CE - GPIO 5
• IRQ - GPIO 6

Important

This example needs to enable SPI1 on Raspberry Pi running Raspbian.

1. Open /boot/firmware/config.txt using editor, like

   sudo nano /boot/firmware/config.txt

   [!Note] Prior to Bookworm, Raspberry Pi OS stored the boot partition at /boot/. Since Bookworm, the boot partition is located at /boot/firmware/. Adjust the previous line to be sudo nano /boot/firmware/config.txt if you have an older OS version.

2. Add the line dtoverlay=spi1-3cs and save

3. Reboot

When you using SPI1, you need to pass ID = 1, CS = 2 into SpiConnectionSettings.

Code

// SPI0 CS0
SpiConnectionSettings senderSettings = new SpiConnectionSettings(0, 0)
{
    ClockFrequency = Nrf24l01.SpiClockFrequency,
    Mode = Nrf24l01.SpiMode
};
// SPI1 CS0
SpiConnectionSettings receiverSettings = new SpiConnectionSettings(1, 2)
{
    ClockFrequency = Nrf24l01.SpiClockFrequency,
    Mode = Nrf24l01.SpiMode
};
var senderDevice = SpiDevice.Create(senderSettings);
var receiverDevice = SpiDevice.Create(receiverSettings);

// SPI Device, CE Pin, IRQ Pin, Receive Packet Size
using (Nrf24l01 sender = new Nrf24l01(senderDevice, 23, 24, 20))
{
    using (Nrf24l01 receiver = new Nrf24l01(receiverDevice, 5, 6, 20))
    {
        // Set sender send address, receiver pipe0 address (Optional)
        byte[] receiverAddress = Encoding.UTF8.GetBytes("NRF24");
        sender.Address = receiverAddress;
        receiver.Pipe0.Address = receiverAddress;

        // Binding DataReceived event
        receiver.DataReceived += Receiver_ReceivedData;

        // Loop
        while (true)
        {
            sender.Send(Encoding.UTF8.GetBytes("Hello! .NET Core IoT"));

            Thread.Sleep(2000);
        }
    }
}

private static void Receiver_ReceivedData(object sender, DataReceivedEventArgs e)
{
    var raw = e.Data;
    var msg = Encoding.UTF8.GetString(raw);

    Console.Write("Received Raw Data: ");
    foreach (var item in raw)
    {
        Console.Write($"{item} ");
    }
    Console.WriteLine();

    Console.WriteLine($"Message: {msg}");
    Console.WriteLine();
}

Result