Overview
The nrf24l01 node interfaces with Nordic Semiconductor nRF24L01+ 2.4GHz
radio transceivers via SPI. These low-cost modules are ideal for building wireless sensor networks with
bidirectional communication, auto-acknowledgment, and multi-pipe addressing. Perfect for home automation,
robotics, and sensor mesh networks.
Properties
| Property | Type | Required | Default | Description |
|---|---|---|---|---|
| spiBus | number | No | 0 | SPI bus number |
| spiDevice | number | No | 0 | SPI chip select (CE0=0, CE1=1) |
| cePin | number | Yes | 22 | GPIO pin for Chip Enable (CE) - not same as SPI CS |
| channel | number | No | 76 | RF channel 0-125 (frequency = 2400 + channel MHz) |
| dataRate | select | No | "1Mbps" | Air data rate: "250kbps", "1Mbps", "2Mbps" |
| paLevel | select | No | "max" | Power amplifier level: "min" (-18dBm), "low" (-12dBm), "high" (-6dBm), "max" (0dBm) |
| txAddress | string | No | "1Node" | 5-byte transmit address |
| rxAddress | string | No | "2Node" | 5-byte receive address |
| autoAck | boolean | No | true | Enable auto-acknowledgment for reliable delivery |
| crcLength | select | No | "16" | CRC length: "disabled", "8" bit, or "16" bit |
Inputs
{
"payload": "temp=23.5",
"txAddress": "1Node"
}{
"payload": {
"data": [0x01, 0x17, 0x00, 0xEA],
"pipe": 0
}
}Outputs
{
"payload": "temp=23.5",
"pipe": 1,
"size": 10,
"ackSent": true,
"timestamp": "2025-01-15T10:30:00.000Z"
}{
"payload": true,
"ackReceived": true,
"retries": 0,
"topic": "nrf24/tx/done"
}Wiring Diagram
nRF24L01+ to Raspberry Pi
nRF24L01+ (8-pin) Raspberry Pi +--------------+ +--------------+ | GND (Pin 1)|------| GND (Pin 6)| | VCC (Pin 2)|------| 3.3V (Pin 1)| | CE (Pin 3)|------| GPIO22(Pin 15)| | CSN (Pin 4)|------| CE0 (Pin 24)| | SCK (Pin 5)|------| SCLK (Pin 23)| | MOSI (Pin 6)|------| MOSI (Pin 19)| | MISO (Pin 7)|------| MISO (Pin 21)| | IRQ (Pin 8)|------| (optional) | +--------------+ +--------------+
Wiring Notes
VCC must be 3.3V (NOT 5V - will damage the module)
CE is Chip Enable, separate from SPI chip select
CSN maps to SPI CS (CE0 on Pi)
IRQ optional interrupt pin for RX notification
Tip: Add a 10uF capacitor between VCC and GND close to the module to stabilize power and prevent dropouts.
Example Use Cases
Wireless Sensor Hub
Receive temperature data from multiple nRF24L01 sensor nodes and log to database.
[
{
"id": "nrf-rx",
"type": "nrf24l01",
"cePin": 22,
"channel": 76,
"dataRate": "1Mbps",
"rxAddress": "HubRx"
},
{
"id": "route-pipe",
"type": "switch",
"property": "pipe",
"rules": [
{ "t": "eq", "v": "0" },
{ "t": "eq", "v": "1" }
]
},
{
"id": "store-db",
"type": "sqlite",
"sql": "INSERT INTO readings (pipe, value, ts) VALUES (?, ?, ?)"
}
]Remote Control with Acknowledgment
Send commands to a remote actuator and verify delivery with auto-acknowledgment.
[
{
"id": "cmd-button",
"type": "button",
"label": "Activate Relay"
},
{
"id": "nrf-tx",
"type": "nrf24l01",
"cePin": 22,
"channel": 76,
"txAddress": "1Node",
"autoAck": true
},
{
"id": "ack-check",
"type": "switch",
"property": "ackReceived"
},
{
"id": "status-debug",
"type": "debug",
"name": "TX Status"
}
]Multi-Node Star Network
Central hub receives from up to 6 sensor nodes using different pipe addresses.
{
"id": "hub-rx",
"type": "nrf24l01",
"cePin": 22,
"channel": 100,
"dataRate": "250kbps",
"paLevel": "max",
"autoAck": true,
"crcLength": "16"
}Common Use Cases
Home Sensor Network
Wireless temperature, humidity, and motion sensors per room
Robotics Control
Remote control and telemetry for robots and drones
Wireless Data Logging
Collect and aggregate sensor data without running wires
Security Zones
Wireless door/window sensors and alarm triggers