Working with X-NUCLEO-NFC10A1 with esp32

[Abhishek_1305]

I am currently working with the X-NUCLEO-NFC10A1 board and interfacing it with an ESP32 DevKit V1. While attempting to establish communication between the two, I have tried all SPI modes as well as different reset logic configurations, but I am still unable to get them to communicate properly.

I have included my Arduino test code below for reference, which I am using to verify the communication:
Please check in attachment section there is code file

[Ulysses HERNIOSUS]

Hi  Abhishek_1305,

Please observe:

Attach a logic analyzer to CS,MISO,MOSI,SCLK,RESET. See that SPI is driven in the right mode according to DS.

If you see the right waveforms and still doesn't work: Double check the supply and the connections. If still not working: Please share the logic analyzer traces + picture of the setup and any other helpful information.

BR, Ulysses

[Brian TIDAL]

Hi,

in your readReg code 

uint8_t readReg(uint8_t reg) {
  uint8_t val;
  SPI.beginTransaction(spiSettings);
  selectChip();
  SPI.transfer(0x40 | reg);
  val = SPI.transfer(0x00);
  deselectChip();
  SPI.endTransaction();
  return val;
}

 SPI.transfer(0x40 | reg); is likely not correct. See Table 3 in the ST25R200 Data Sheet.

A C driver library is available for the ST25R200. It is portable on different MCU (STM32 or other MCUs). It prevents the need to reimplement the driver from scratch. See the X-CUBE-NFC10 package or the ST25 embedded NFC library.

Rgds

BT

[Abhishek_1305]

I am currently working on interfacing the ESP32 with the X-NUCLEO-NFC10A1 board over SPI, and I would like to share my setup along with the steps I’ve already taken.

Here is my current connection configuration:

• ESP32 GPIO23 → MOSI (X-NUCLEO-NFC10A1)
• ESP32 GPIO19 → MISO (X-NUCLEO-NFC10A1)
• ESP32 GPIO18 → SCK (X-NUCLEO-NFC10A1)
• ESP32 GPIO5 → CS (X-NUCLEO-NFC10A1)

I have also attached logic analyzer captures along with my latest code for your reference.
Attached image bytes when I am sending 0x3F register with MSB Bit high and it becomes 0xBF and it gives response 0xFF.

Additionally, I have experimented with all SPI modes by configuring different combinations of CPOL and CPHA, but I am still facing issues with proper communication.
Currently I am using this SPI mode 
Mode 1 (CPOL=0, CPHA=1): Clock idles low, data sampled on falling edge.

Could you please review my setup and provide guidance on what might be going wrong or any additional configurations I should check?

[Brian TIDAL · Accepted solution]

Hi,

make sure VDD and VDD_IO are both provided to the X-NUCLEO-NFC10A1. Make sure the various GND pins are properly connected. 

Could you also send a picture of your setup?

Strange to see MISO always at 1. Could you check MISO/MOSI have not been swapped?

Rgds

BT

[Ulysses HERNIOSUS]

Hi,

things to check:

• Is MISO in input state of MCU? Possibly open it up and observe only on ST25R side.
• Observe signals with a scope: Are the levels correct? Is the ST25R trying to respond?

Ulysses

[Abhishek_1305]

Dear STM Community Support Team,

Thank you for resolving my issue so quickly. I appreciate your support and assistance.