NFC initialization fails with voltage measure error.

[Quarin]

I'm using the NFC 52840DK. When I try to run any of the NFC examples, I get the following error:

*** Booting Zephyr OS build v2.4.0-ncs2  ***
NFC TNEP Poller sample started.
[00:00:02.374,786] [1;31m st25r3911b: Voltage measure failed[0m
[00:00:02.374,816] [1;31m st25r3911b: st25r3911b initialization failed[0m
NFCA initialization failed err: -6.

It gives this error wether the NFC antenna (supplied with the DK) is connected or not. I tried both directions of the antenna, but that does not make a difference. The antenna itself is pushed all the way into the connector. When the NFC antenna is connected, it looks the same as the images I can find online.

Are there any measurements I can do to rule out a hardware issue?

[Kenneth]

Hi,

There should be several NFC examples you can try:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples.html#

Note however that some of the NFC examples require external hardware in addition, for instance:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/nfc/tnep_poller/README.html

The sample has the following additional requirements:

• NFC Reader ST25R3911B Nucleo expansion board (X-NUCLEO-NFC05A1)

• NFC Type 4 Tag TNEP device

The reason for this is that the nRF does not contain an on-chip NFC reader/poller, but you should be able to run all examples that is NFC tag without external hardware.

Kenneth

[HPN]

Hi Kenneth,

can you please dig into how to interface nrF52840Dk with X-NUCLEO-NFC05A1?

support for ISO 15693 has been added to the nordic wrapped lib for managing the ST25R3911B platform?

Thanks,

HPN 

[Kenneth]

Looking at the tag_reader example project I can find that the nRF52840DK is by default setup to use spi0 for the st25r3911 and the pins used is found in this file:
https://github.com/nrfconnect/sdk-nrf/blob/main/samples/nfc/tag_reader/nrf52840dk_nrf52840.overlay 

Best regards,
Kenneth

[HPN]

Hi Kenneth,

the example we used is exactly the one you suggested, with the dts configured as in the link. 

However, we get both the "Voltage measure failed" and "Oscillator start failed" errors... it is strange. But surely we are missing something

Best,

HPN

[Kenneth]

I would likely have connected a logic analyzer to the spi interface to look at the spi data and compare with the datasheet. This should narrow down if the problem is electrical or software.

Kenenth