ST25R3911B SPI and ST25R3911B Discovery GUI has no commincatin

[DAbba]

Hi everybody 

I am using st25r3911 in my own pcb and I still have a problem in the first step :

rfalInitialize() does not return ERR_NONE

in fact I see the MOSI and CLK and CS signal but there is not anything in MISO !!

pin28 in st25r3911b (mcu_clk) is ok so i think the chip is working .

[Ulysses HERNIOSUS · Accepted solution]

Hi Dariush,

can you measure the IRQ pin, if it is high when this condition occurs.

Reading the STM8 reference manual I suspect that our code should be changed to:

diff --git a/Firmware/nucleo/X-NUCLEO-NFC05A1/STM8/Project/stm8s_it.c b/Firmware/nucleo/X-NUCLEO-NFC05A1/STM8/Project/stm8s_it.c

index 2a87cda..ddb5575 100644

--- a/STM8/Project/stm8s_it.c

+++ b/STM8/Project/stm8s_it.c

@@ -129,7 +129,7 @@ INTERRUPT_HANDLER(EXTI_PORTA_IRQHandler, 3)

  */

 @svlreg INTERRUPT_HANDLER(EXTI_PORTB_IRQHandler, 4)

 {

- if( (GPIO_ReadInputData(GPIOB) & GPIO_PIN_5) )

+ while( (GPIO_ReadInputData(GPIOB) & GPIO_PIN_5) )^M

    {

        st25r3911Isr();

    }

@@ -513,4 +513,4 @@ INTERRUPT_HANDLER(EEPROM_EEC_IRQHandler, 24)

  */

Please try and tell me the results of your investigation. Also I think it makes sense you start a new thread with a proper topic.

Regards, Ulysses

[DAbba]

Finally I did it, I have communication by USB to ST25R3911B Discovery GUI now.

now I have a new problem .

despite the fact that I am sure that there is noting in the antenna field , I always see this message when I use calibrate antenna button.

what is wrong in my antenna and how I can fix it ?

I have made my own antenna circuit similar to st25r3911_dico_mb1325 .

[Ulysses HERNIOSUS]

Hi Dariush,

the chip-interal antenna tuning algorithm requires to be able to find a phase close to the target phase of 90deg. It seems your antenna is off in this respect. Please have a look at the proper app notes: AN4974 and AN4914.

Regards, Ulysses

[Travis Palmer]

​Hi Dariush,

This means, that you are trying to use AAT, but the algorithm was not sucessfull.

This can either mean, that you try using AAT but the lines are not connected (if you opened J406 and/or J407) or that your antenna is too much detuned and AAT cannot optimize your tuning further.

If you have disconnected AAT via J406 and J407 simply do not execute Calibrate antenna.

In the other case if the tuning seems not to be at the right spot. I recommend you to remove any metal from the suronding and try again. If this does not help, measure the matching network using a VNA.

Please keep in mind, if you are attaching a VNA to the board that the board should be either not powered or the driver has been put to high-Z state by setting Register 27h to 0xFF. Otherwise your VNA could be damaged.

Guidance about finding the right matching impedance can be found in the antenna design appnote on st.com.

BR Travis