SPI interface for STM32L476VG

[RShiv.1]

STM32L476VG is the MCU we are interfacing with ST25R3911B using SPI.

what we have understood from some search is that we need RFAL (abstraction layer) to interface with RF HAL.

Then once we integrate RFAL and RF HAL in our system workbench(ac6) project we need to build the integration then use SPI calls to read the register from RFID reader ST25R3911B

we wanted to use ISO-14443A standard to be configured and read the values.

where do we get the basic RFAL work space or code flow so that we shall use in our current project?

Kindly guide us and let us know are we in right path?

[Brian TIDAL]

HI,

if the SPI is working properly, if you see proper responses from ST25R3911B on MISO, well, I would say it looks like either an HW issue (line being pulled up by another device) or the MCU GPIO is not properly configured (i.e. GPIO being in output pull up mode). Please provide a logic analyzer trace so I can check SPI communication is correct.

Rgds

BT

[RShiv.1]

Hi BT,

Fine we will check this..but we do not have an analyser trace..we will share you the trace from scope(oscilloscope)..should be fine right.

regards

Ravi

[Brian TIDAL]

Hi,

1/ can you confirm you see the following log message:

• "Initialization succeeded..\r\n"
• "SPI init passed..\r\n"?

2/ disconnect the interrupt line from the ST25R3911B and connect the GPIO on 3V3 and then on Gnd: do you see the interrupt being triggered on MCU side?

Rgds

BT

[RShiv.1]

Hi BT,

we are getting SPI

• yes we are getting Initialization succeeded..\r\n"
• "SPI init passed..\r\n"?

we will answer the 2nd one for you shortly.

regards

Ravi

[RShiv.1]

Hi BT,

we did the test for the 2nd point and still not seeing any result..I have also attached the ioc.file..can you confirm whether we need to configure PA3 as GPIO_EXTI3 or as GPIO_INPUT...let me know whether the configurations are correct..

regards

Ravi

[RShiv.1]

Hi BT,

also attaching the main.c file

[RShiv.1]

Hi BT,

since Interrupt is coming from ST25R3911 it must be GPIO_INPUT..is this correct??

regards

Ravi

[Brian TIDAL]

Hi,

as explained in previous posts, the PA3 GPIO connected to the interrupt line has to be configured as GPIO_EXTI3 external interrupt mode with rising edge trigger detection.

If the interrupt is not seen, I suggest to check the board with your HW engineer.

Rgds

BT

[RShiv.1]

Hi Bt,

But we are using discovery board along with NFC05A1...even here the interrupt is not seen...then do you suggest this as hardware issue??.

regards

ravi

[Brian TIDAL]

Hi, You mean you are using the ST25R3911B-DISCO and have connected the SPI + IRQ from X-NUCLEO-NFC05A1 on P204 points and have isolated the onboard ST25R3911B?

Well, in that case, the IRQ pin is connected to PA0 EXTI0 (see schematicshttps://www.st.com/content/ccc/resource/technical/layouts_and_diagrams/schematic_pack/group0/71/e3/fd/6c/0c/db/42/21/Schematics-ST25R3911B-DISCO-MB1325/files/Schematics-ST25R3911B-DISCO-MB1325.PDF/jcr:content/translations/en.Schematics-ST25R3911B-DISCO-MB1325.PDF).

So if using the the ST25R3911B-DISCO, you have to modify you SW to use PA0 instead of PA3.

Rgds

BT