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I'm a Raspberry Pi n00b and a python beginner, but I have a lot of experience with DIY electronics, arduino and c#.

I've tried everything I can think of, and I just can't get the Pi to recognise the RF24.

here's my setup

Raspberry Pi 3 model B nRF24L01+

I'm using this tutorial which uses the Blavery version of the RF24 library, but I have tried at least 4 different tutorials and libraries, which all seem pretty similar.

here is the code:

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

GPIO.setmode(GPIO.BCM)

pipes = [[0xe7, 0xe7, 0xe7, 0xe7, 0xe7], [0xc2, 0xc2, 0xc2, 0xc2, 0xc2]]

radio = NRF24(GPIO, spidev.SpiDev())
radio.begin(0, 17)
radio.setPayloadSize(32)
radio.setChannel(0x60)

radio.setDataRate(NRF24.BR_1MBPS)
radio.setPALevel(NRF24.PA_MIN)
radio.setAutoAck(True)
radio.enableDynamicPayloads()
radio.enableAckPayload()

radio.openReadingPipe(0, 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(string)
    radio.writeAckPayload(1, ackPL, len(ackPL))
    print("Loaded payload reply of {}".format(ackPL))

and here is the output:

Warning (from warnings module):
  File "/home/pi/Desktop/NRF24L01/lib_nrf24.py", line 377
    self.GPIO.setup(self.ce_pin, self.GPIO.OUT)
RuntimeWarning: This channel is already in use, continuing anyway.  Use GPIO.setwarnings(False) to disable warnings.
STATUS   = 0x0e RX_DR=0 TX_DS=0 MAX_RT=0 RX_P_NO=7 TX_FULL=0
RX_ADDR_P0-1    � = 0x0808080808 0x0808080808 
RX_ADDR_P2-5    � = 0x08 0x08 0x08 0x08 
TX_ADDR      = 0x0808080808 
RX_PW_P0-6  � = 0x08 0x08 0x08 0x08 0x08 0x08 
EN_AA        = 0x08 
EN_RXADDR   � = 0x08 
RF_CH        = 0x08 
RF_SETUP    � = 0x08 
CONFIG       = 0x08 
DYNPD/FEATURE   � = 0x08 0x08 
Data Rate    = 2MBPS
Model        = nRF24L01
CRC Length   = 8 bits
PA Power     = PA_MIN

Sometimes the addresses are different, but they never match the addresses from the code.

I've tried checking all the wiring with a multimeter, and it seems to be solid. I've tried with many different wires including ribbon cable directly to the nRF24 module and using a breadboard with the breakout. I tried using a capacitor on the power supply to the RF24. I tried sever different RF modules, all of which I tested with an Arduino and they work fine. I tried it with a Raspberry Pi 2, and had more or less the same results.

As its my first time using Pi, I don't really know the steps for how to debug the problem. I unfortunately don't have an oscilliscope/signal analyzer, so it's hard to test the serial pins. Any suggestions would be greatly appreciated!

thanks

Oliver Appling Bucklin
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  • Have you tried using this code I wrote for pigpio? https://raspberrypi.stackexchange.com/a/77353/13650 – joan Jul 10 '18 at 16:59

3 Answers3

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This was too long to be a comment ...

  • You can get fix the warning by calling GPIO.cleanup() at the appropriate location.
  • Have a look at this post.
    • Seems to indicate either a dead nRF (less likely in your case given you got it working with an arduino)
    • SPI is not working (enabled ?). You should confirm SPI is correctly enabled
  • Try the example here as is and see if that works as expected ?
    • If it does, its probably your code, if it does not it is probably something else being overlooked
    • I noticed there is a time.sleep(1) call in the example code like so (but missing in yours ... may be its is required ?)
radio = NRF24(GPIO, spidev.SpiDev())
radio.begin(0, 17)
time.sleep(1)                        # missing 
radio.setRetries(15,15)
radio.setPayloadSize(32)
radio.setChannel(0x60)
Shreyas Murali
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WOW

ok so I saw this post and just gave it a try, and it worked. That is to say I just swapped the old RF24 module out for a new one and BOOM. I guess the radios don't like 5v at all

Oliver Appling Bucklin
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  • The datasheet is quite explicit. Power Supply +1.9V - +3.6V DC – joan Jul 10 '18 at 17:55
  • Please accept your own answer with a click on the tick on its left side. Only this will finish the question and it will not pop up again year for year. – Ingo Feb 09 '20 at 19:52
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This answer fixed my issues

In lib_nrf24.py in function:

def begin(self, csn_pin ... after self.spidev.open add:

self.spidev.max_speed_hz = 4000000
Jak
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