Problem with NRF24L01+ Transceiver, OSError Hardware not responding

[castus]

Hi,

I have a problem. I'm new to Pico and IoT. I wanted to test NRF24L01+ transceiver but I'm unable to run it. I'm constantly receiving an error

OSError: nRF24L01+ Hardware not responding

I'm using Pico H 2021 with connections like that:
CE on 17
CSN on 14
SCK on 6
MISO on 4
MOSI on 7
SPI 0

and script: nrf24l01.py and test script nrf24l01test.py with changed configuration to:

if usys.platform == "pyboard":
    cfg = {"spi": 2, "miso": "Y7", "mosi": "Y8", "sck": "Y6", "csn": "Y5", "ce": "Y4"}
elif usys.platform == "esp8266":  # Hardware SPI
    cfg = {"spi": 1, "miso": 12, "mosi": 13, "sck": 14, "csn": 4, "ce": 5}
elif usys.platform == "esp32":  # Software SPI
    cfg = {"spi": -1, "miso": 32, "mosi": 33, "sck": 25, "csn": 26, "ce": 27}
elif usys.platform == "rp2":  # PI PICO
    cfg = {"spi": 0, "miso": 4, "mosi": 7, "sck": 6, "csn": 14, "ce": 17}
else:
    raise ValueError("Unsupported platform {}".format(usys.platform))

I triple-checked connections and everything is in place but it's not working.

Could you help me to find out what's going on?

I really appreciate any help you can provide.

[peterhinch]

You are probably the first to try NRF24L01 with RP2. I think the problem is with this line. RP2 seems to require SPI to be initialised with named args for sck mosi and miso.

The quick fix is to change the SPI number to -1 which uses that form of initialisation.

[castus]

Unfortunately, this doesn't work. It gives me an error that there is no SPI -1. I gave up on this. It's tough to communicate between those modules even though there are many videos on YT. Thanks anyway @peterhinch

[jimmo]

Instead of SPI(-1, ...pins), use SoftSPI(...pins).

i.e. in nrf24l01test.py, add your pin config to the dict on line 23, then change line 35 to say spi = SoftSPI(sck=...) rather than spi = SPI(-1, sck=...).

[peterhinch]

@jimmo Of course you are right. This means that nrf24l01_test.py is out of date as I copied the -1 value from the ESP32 case. I'll submit a PR to fix this for ESP32 and RP2.

[peterhinch]

I have raised micropython/micropython-lib#568 which addresses this and other issues with the test script.