ST25DV-i2c energy harvesting and GPO with stm32l031k6

[WPARK.1]

Hello, I am trying to open a project that can turn on the low power MCU stm32l031 with ANT7-T-25DV64KC while turning high and low periodically for GPO pin of the MCU. I tried many different ways but still not done with any of them (steval code and using NFC4 and 7 provided by stm32cubeide).

Would you please suggest me for any reference or sample for St25DV-i2c?

[Rene Lenerve]

Hi @WPARK.1​ ,

So what you need is a nucleo board, with this kit you can build your application more easily (thanks to arduino connectors) than modifying boards like SMARTAG or Discovery boards (They are demo boards and aim to show each features of the component and examples of what we can do with).

Nucleo boards are development kits ans I think better solution for you. You start with the MCU board (there is a choice of MCU) and you can add expansion boards to have more functionalities (for example NFC4 or NFC7 to have NFC tag). The software package includes simple examples to start your development. For example with the NFC4 and NFC7 you can find a simple example on how to enable the Energy Harvesting on the ST25DVxxK / ST25DVxxKC.

The communication through I2C is the same as a standard EEPROM memory. BSP drivers are provided with the nucleo package to communicate with our NFC tags.

I hope this can help you.

Kind Regards.

[WPARK.1]

Hello,

The reason why I want to use STM32L031K6 is that it is small and low power MCU. However, I checked that there is no example project built for STM32L031K6 but STM32L053 yes. (As I am working on wearable electronics, the size of the circuit is really critical.)

So what I can do is that I buy Nucleo board of STM32L053 and X-NUCLEO-NFC07A1 to train with the sample code right? (Actually I tried with STMF4 nucleo and ANT7-T-25DV64KC. I tried to modify MX_NFC7_EH_Process to remove the button function (as I always want it to be on while RF is detected, the code was stuck and cannot operate anymore).

Thank you for reading.

[Rene Lenerve]

Hi @WPARK.1​,

Starting from the EH example is fine. When connecting I2C from ANT7-T-25DV64KC to STMF4 nucleo, you also need to connect pull-up resistors to this bus otherwise it will not be able to communicate with the tag.

When you say the code was stuck, can you give more details on where it is stuck?

For the EH feature you need to activate it only once and it will be available each time an RF reader approach the antenna.

Kind Regards.

[WPARK.1]

Hello,

I found out that my STMF4 board is based on STM32F407VET6. Therefore, the sample codes are not very fit to me in this moment. So, as currently, I don't have suitable pull up resistors at home, I would like to use FLEX-ST25DV64KC. I tried to check the pin diagram of FLEX-ST25DV64KC but I could not find any reference.

Therefore, can I have any references?

Thank you for reading.

[WPARK.1]

Hello,

I ordered NUCLEO-L053R8 and X-NUCLEO-NFC07A1. It is expected to be arrived around 1 week later.

What I would like to try is that

1. Open the sample project with STM32CubeIDE.
2. Remove all the buttons and LED functions for customized library (In my understanding, I should modify MX_NFC7_EH_Process and MX_NFC7_EH_Init (detach all the BSP functions related to buttons and LEDs).

When I got the board and if there is any problem, I would continue the thread.

Thank you for reading.

[Rene Lenerve]

Hi @WPARK.1​,

It seems that there is a missing document for the ST25DV64KC-DISCO, we will check to fix this point.

For information the pin of the Flex antenna is as follows:

pin 1 : VCC

pin 2 : Ground

pin 3 : I²C SDA

pin 4 : I²C SCL

pin 5 : GPO

pin 6 : Ground

pin 7 : Energy Harvesting

pin 8 :Not Connected

Hope this can help.

Kind Regards.

[WPARK.1]

Hello,

Now I received NUCLEO-L053R8 and X-NUCLEO-NFC07A1 and operating EH example provided by STM32CubeIde. However, there is a problem in MX_NFC7_EH_Init.

On debug mode, if I "Step Into"  while( NFC07A1_NFCTAG_Init(NFC07A1_NFCTAG_INSTANCE) != NFCTAG_OK );, it is not stuck but on running mode and if I do "Step Over", the whole section of firmware is stuck.

Thank you for reading.

[WPARK.1]

Same thing happens for NDEF example.

I think

while( NFC07A1_NFCTAG_Init(NFC07A1_NFCTAG_INSTANCE) != NFCTAG_OK );

while( NfcType5_TT5Init( ) != NFCTAG_OK );

These lines having some problem as it cannot return NFCTAG_OK without manually "Step Into" in the debug mode. (Running mode stuck after LEDs are turned on).

Thank you for reading.

[WPARK.1]

For NDEF example,

For: while( NfcType5_TT5Init( ) != NFCTAG_OK );

Totally stuck even though I did "Step Into". Therefore, it does not turn off LEDs at all.

[Rene Lenerve]

Hi @WPARK.1​,

I have downloaded NFC7 v1.0.0 package on st.com, and I tried both projects, it was working fine in debug and running mode for me. I tried with STM32CubeIDE and Keil and same behavior with debug and running mode.

Can you get the value returned by nfctag_id in the function ST25DVxxKC_Init from st25dvxxKC.c file (both in debug and running mode) to see if the program read the correct value (for NFC7 should be 0x50 or 0x51).

Kind Regards.