Print Friendly, PDF & Email

Difficulty level: Beginner

Approx reading time:

Components Required:

1. Raspberry Pi 3 model B

2. Arduino Uno

3. MicroSD card 8 or 16 GB (Class 4 and above) with Raspbian – 2

4. Windows PC / Linux PC (Tested on Windows 10, Ubuntu 14.04 LTS)

5. Ethernet cable (Category 5 – also called Cat 5)

6. Micro USB cable and USB cable type A/B (for Arduino)

7. Breadboard

8. NRF24L01+ Transceiver – 2

9. Jumper Wires (Male to Female, Male to Male)

Way to go ->

1. Login to both your devices using PuTTy or your Ubuntu terminal.

2. Login to both your devices’ GUIs using VNC server (Linux / Windows).

Do the following for both the devices:

3. In the terminal type: 

sudo raspi-config

and press Enter on your PC keyboard.

Follow steps 7 – 9 of RPi 3 Tutorial – 11 for steps 4 – 6.

4. Go to Advanced Options.

5. Go to SPI.

6. Enable SPI Interface by clicking on <Yes>.

7. Reboot the Pi. In the terminal, type: 

sudo reboot

8. In the terminal type: 

sudo apt-get update

9. After it has rebooted, install Python development tools. In the terminal, type:

sudo apt-get install python-dev.  # python2

sudo apt-get install python3-dev.  # python3

10. Download this package. In the terminal type:

wget https://github.com/Gadgetoid/py-spidev/archive/master.zip

11. In the terminal type: ls to check that you have master.zip in your current working directory.

12. To unzip, in the terminal type: 

unzip master.zip

13. Remove master.zip: 

rm master.zip

14. Navigate to py-spidev-master directory(folder): 

cd py-spidev-master

15. Type in the terminal: ls, to view the contents of the directory(folder).

16. In the terminal run the commands:

sudo python setup.py install  # python2

sudo python3 setup.py install  # python3

17. Navigate to the desktop by running the following commands. In terminal type:

cd ..

Press Enter on your PC keyboard.

cd Desktop/

Press Enter on your PC keyboard.

18. Create the following directory(folder) and navigate to it. In terminal type:

mkdir NRF24L01

Press Enter on your PC keyboard.

cd NRF24L01/

Press Enter on your PC keyboard.

19. In the terminal type:

git clone https://github.com/Blavery/lib_nrf24

20. Navigate to directory just downloaded. In the terminal type:

ls

Press Enter on your PC keyboard.

cd libnrf24/

Press Enter on your PC keyboard.

ls

Press Enter on your PC keyboard.

21. Copy lib_nrf24.py to the NRF24L01 directory. In the terminal type:

cp lib_nrf24.py ~/Desktop/NRF24L01/

22. Navigate to the NRF24L01 directory:

cd..

ls

23. In Python 3 (IDLE), create a new file.

24. The name could be: ReceiveArduino.py. Save it in the NRF24L01 directory(folder).

25. In the file ReceiveArduino.py, write the following code with comments (line starting with “#”) for clear understanding and save (press Cntrl + S on your PC keyboard) the file.

import RPi.GPIO as GPIO
from lib_nrf24 import NRF24
import time
import spidev

GPIO.setmode(GPIO.BCM)

pipes = [[0xE8, 0xE8, 0xF0, 0xF0, 0xE1], [0xF0, 0xF0, 0xF0, 0xF0, 0xE1]]

radio = NRF24(GPIO, spidev.SpiDev())
radio.begin(0, 17)

radio.setPayloadSize(32)
radio.setChannel(0x76)
radio.setDataRate(NRF24.BR_1MBPS)
radio.setPALevel(NRF24.PA_MIN)

radio.setAutoAck(True)
radio.enableDynamicPayloads()
radio.enableAckPayload()

radio.openReadingPipe(1, pipes[1])
radio.printDetails()
radio.startListening()

while(1):
    # ackPL = [1]
    while not radio.available(0):
        time.sleep(1 / 100)
    receivedMessage = []
    radio.read(receivedMessage, radio.getDynamicPayloadSize())
    print("Received: {}".format(receivedMessage))

    print("Translating the receivedMessage into unicode characters")
    string = ""
    for n in receivedMessage:
        # Decode into standard unicode set
        if (n >= 32 and n <= 126):
            string += chr(n)
    print("Out received message decodes to: {}".format(string))

 26. Open the Arduino IDE.

 26

27. In the above menu bar go to: Sketch -> Include Library -> Manage Libraries…

27

28. Search for RF24, select RF24 by TMRh20 Version 1.1.6 and click Install. After installation close the library manage.

28

29. Write the following program in the Arduino IDE and Upload it to the Arduino. Send.ino

//Send.ino

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

// ce, csn pins
RF24 radio(9, 10);

void setup(void){
	radio.begin();
	radio.setPALevel(RF24_PA_MAX);
	radio.setChannel(0x76);
	radio.openWritingPipe(0xF0F0F0F0E1LL);
	radio.enableDynamicPayloads();
	radio.powerUp();

}

void loop(void){
    const char text[] = "Hello World is awesome";
	radio.write(&text, sizeof(text));
	delay(1000);

}

30. Finally, run the script on the Pi by clicking on Run -> Run Module in the menu bar or by pressing F5 on your PC keyboard.

ReceiveArduino.py output

RPiArduinoRxOutput

31. For a master/slave setup.

SendReceiveArduino.py(Pi)

import RPi.GPIO as GPIO
from lib_nrf24 import NRF24
import time
import spidev

GPIO.setmode(GPIO.BCM)

pipes = [[0xE8, 0xE8, 0xF0, 0xF0, 0xE1], [0xF0, 0xF0, 0xF0, 0xF0, 0xE1]]

radio = NRF24(GPIO, spidev.SpiDev())
radio.begin(0, 17)

radio.setPayloadSize(32)
radio.setChannel(0x76)
radio.setDataRate(NRF24.BR_1MBPS)
radio.setPALevel(NRF24.PA_MIN)

radio.setAutoAck(True)
radio.enableDynamicPayloads()
radio.enableAckPayload()

radio.openWritingPipe(pipes[0])
radio.openReadingPipe(1, pipes[1])
radio.printDetails()
# radio.startListening()

message = list("GETSTRING")
while len(message) < 32:
    message.append(0)

while(1):
    start = time.time()
    radio.write(message)
    print("Sent the message: {}".format(message))
    radio.startListening()

    while not radio.available(0):
        time.sleep(1 / 100)
        if time.time() - start > 2:
            print("Timed out.")
            break

    receivedMessage = []
    radio.read(receivedMessage, radio.getDynamicPayloadSize())
    print("Received: {}".format(receivedMessage))

    print("Translating the receivedMessage into unicode characters")
    string = ""
    for n in receivedMessage:
        # Decode into standard unicode set
        if (n >= 32 and n <= 126):
            string += chr(n)
    print("Out received message decodes to: {}".format(string))

    radio.stopListening()
    time.sleep(1)

SendReceive.ino(Arduino)

//SendReceive.ino

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

// CE, CSN pins
RF24 radio(9, 10);

void setup(void){
	while(!Serial);
	Serial.begin(9600);

	radio.begin();
	radio.setPALevel(RF24_PA_MAX);
	radio.setChannel(0x76);
	radio.openWritingPipe(0xF0F0F0F0E1LL);
	const uint64_t pipe = (0xE8E8F0F0E1LL);
	radio.openReadingPipe(1, pipe);

	radio.enableDynamicPayloads();
	radio.powerUp();
	
}

void loop(void){
	radio.startListening();
	Serial.println("Starting loop. Radio on.");
	char receivedMessage[32] = {0};
	if(radio.available()){
		radio.read(receivedMessage, sizeof(receivedMessage));
		Serial.println(receivedMessage);
		Serial.println("Turning off the radio.");
		radio.stopListening();

		String stringMessage(receivedMessage);

		if(stringMessage == "GETSTRING"){
			Serial.println("Looks like they want a string!");
			const char text[] = "Yo wassup, haha";
			radio.write(text, sizeof(text));
			Serial.println("We sent our message.");
		}
	}
	delay(100);

}

SendReceive.ino(Arduino) output

SlaveArduino

SendReceiveArduino.py(Pi) output

MasterPi

Hardware Connections ->

1. Raspberry Pi 3 GPIO Header.

pi3_gpio

2. nRF24L01 pinout

nrf24l01_module_pinout

3. nRF24L01 to Pi connections.

RFToPiConnections

RFToPi_schem

RFToPi_bb

4. nRF24L01 to Arduino Uno connections.

RFToArduinoConnections

ArduinoToRF_schem

Read full tutorial at

Rating widget: