Who_AM_I problem on IIS3DWBTR

[KTanaka]

Hellow community,

I'm currently working with the IIS3DWBTR sensor, which I purchased from Mouser Electronics. I've encountered an issue where the `WHO_AM_I` register (0Fh) is returning a value of `0x76`, whereas the expected value is `0x7B`.

The SPI bus signal seems fine, and I've checked the usual suspects such as clock speed, voltage levels, and signal integrity. The sensor initialization also appears to be correct.

Has anyone else experienced this issue or have any suggestions on what might be causing this discrepancy? Any help would be greatly appreciated.

Best,

[Federica Bossi]

Hi @KTanaka ,

Welcome to ST Community!

Can you share more information about your setup? And also your schematic?

Thanks

[KTanaka]

Hi Federica,

I share my setup as bellow.
MCU R7FA6T2BD3CFP on HSBRA6T2F100, Hokuto electronics
SPI mode 3 / active high clock and
clock 10MHz
I also checked 400kHz, but it didn't solve the problem.

I will also share the command flow.
Read 0x0F and received 0x76 (01111011)
Write 0b0000 0100 to 0x10
Read 0x10 and received 0b0000 0000
Write 0b0000 0000 to 0x15
Write 0b1010 0100 to 0x10
Read 0x10 and receive 0b1000 0000

And I share my schematic of IIS2DWB test piece.

Thanks

[KTanaka]

Dear Community,

I apologize for the confusion, but I mistakenly marked a post as "Solution Approved". Upon further review, I realized that the issue has not been resolved. I would also like to request if it's possible to remove the "Solution Approved" tag from the post. I appreciate your understanding and patience as we continue to work on this.

Best Regards,

[KTanaka]

I also share my screenshot of my oscilloscope signal between mcu and the sensor.

[Federica Bossi · Accepted solution]

Hi @KTanaka ,

From the schematic I noticed that PIN 10 and PIN11 are connected to GND, but from our specifications, reported in the datasheet, they should be connected to VDD_IO or left unconnected. Try this and let me know if this solves.

[KTanaka]

Thank you for your good answer.

It was very helpful.

I will make that correction in the next version