nRF24L01 is a single chip radio transceiver for the world wide 2.4 - 2.5 GHz ISM band. The transceiver consists of a fully integrated frequency synthesizer, a power amplifier, a crystal oscillator, a demodulator, modulator and Enhanced ShockBurst™ protocol engine.
Output power, frequency channels, and protocol setup are easily programmable through a SPI interface. Current consumption is very low, only 9.0mA at an output power of -6dBm and 12.3mA in RX mode. Built-in Power Down and Standby modes makes power saving easily realizable.
Board
Communicating with the Board
This board uses SPI, Serial Peripheral Interface.
The SPI bus specifies four logic signals:
- SCLK: Serial Clock (output from master)
- MOSI: Master Output Slave Input, or Master Out Slave In (data output from master)
- MISO: Master Input Slave Output, or Master In Slave Out (data output from slave)
- SS: Slave Select (often active low, output from master)
Hookup
Sample TX Code
| Code Block |
|---|
#include <SPI.h>
#include "RF24.h"
/*
* Sample Transmitter
*
* CLK 14
* MOSI 13
* MISO 12
* CS 15
* CE 8
*/
#define CE_PIN 8
#define CS_PIN 15
RF24 radio(CE_PIN,CS_PIN);
byte addresses[][6] = {"i8-00","I8-00"};
char buf[1];
int bufsize=1;
void setup() {
Serial.begin(115200);
Serial.println(F("\n\ni8 Tx Started"));
Serial.println(F("*** PRESS 'B-G' to represent button"));
radio.begin();
// Set the PA Level low to prevent power supply related issues.
radio.setPALevel(RF24_PA_LOW);
radio.setRetries(15,15);
radio.setPayloadSize(8);
radio.setDataRate(RF24_1MBPS);
radio.setAutoAck(1); // Ensure autoACK is enabled
radio.openWritingPipe(addresses[0]);
radio.stopListening();
}
void loop() {
// process serial requests
if ( Serial.available() )
{
char c = toupper(Serial.read());
//'B', 'C', 'D', 'E', 'F', 'G'
if(c >= 'B' && c <= 'G'){
Serial.printf("> %c \n",c);
buf[0]=c;
int v = radio.write(&buf, bufsize);
buf[0]=tolower(c);
v = radio.write(&buf, bufsize);
}
}
}
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References
| Reference | URL |
|---|---|
| Spec | https://www.sparkfun.com/datasheets/Components/nRF24L01_prelim_prod_spec_1_2.pdf |
| Tutorial | https://howtomechatronics.com/tutorials/arduino/arduino-wireless-communication-nrf24l01-tutorial/ |
| Demo 41: ESP32 connects with nRF24L01 2.4 GHz wireless chip | http://www.iotsharing.com/2018/03/esp-and-raspberry-connect-with-nrf24l01.html |