Not able to read IMU data.

RE: Not able to read IMU data.

NRF52833 — Fri, 10 May 2024 08:04:46 GMT

Hii,

The issue got solved . I need to enable Testing FIFO mode in order to read the accelerometer data.

Thanks

RE: Not able to read IMU data.

NRF52833 — Fri, 03 May 2024 08:52:23 GMT

Now, I got it. It is detecting the device at 0x19. But now when I run my accelerometer code it is showing all x,y,z values as 0.

Do you know why is it. I tried to move the chip still the values were zero.

RE: Not able to read IMU data.

Håkon Alseth — Fri, 03 May 2024 07:28:33 GMT

Please note that SCL is at P1.04, not P0.04.

That means the define should expand to "32+4" not "4".

Kind regards,

Håkon

RE: Not able to read IMU data.

NRF52833 — Fri, 03 May 2024 07:20:13 GMT

Hii,

When I use stock twi_scanner , I get "no device was found"

RE: Not able to read IMU data.

Håkon Alseth — Fri, 03 May 2024 07:14:58 GMT

Could you scope the pins using an oscilloscope or logic analyzer?

Do you get a successful transaction on the address while using the stock (unchanged) twi_scanner?

Kind regards,

Håkon

RE: Not able to read IMU data.

NRF52833 — Thu, 02 May 2024 20:04:30 GMT

Yes, I have checked the address is 0x19 and the pins are SCL_04 and SDA_24.

RE: Not able to read IMU data.

Håkon Alseth — Thu, 02 May 2024 14:55:53 GMT

Hi,

q1: Have you double-checked that the address is correct?

q2: Have you scoped the SDA/SCL pins to see if there is any communication at all? Looks like it is P0.24 and P1.04 that is used, according to the datasheet of the module you're using.

Kind regards,

Håkon

RE: Not able to read IMU data.

NRF52833 — Thu, 02 May 2024 11:08:02 GMT

I tried this, still the error is same:

00> <error> app: ERROR 33281 [NRF_ERROR_DRV_TWI_ERR_ANACK] at D:\nRF5_SDK_17.1.0_ddde560\nRF5_SDK_17.1.0_ddde560\examples\Myprojects\twi_scanner\main.c:88
00>
00> PC at: 0x00000623
00>
00> <error> app: End of error report
00>

I think its not able to communicate with the accelerometer on the chip .

RE: Not able to read IMU data.

Håkon Alseth — Thu, 02 May 2024 10:42:12 GMT

Hi,

You need to set this line:

.frequency          = NRF_DRV_TWI_FREQ_400K,

To:

.frequency          = NRF_DRV_TWI_FREQ_100K,

internal pull-ups are enabled in the nrfx_twi/nrfx_twim driver by default in nRF5 SDK.

Kind regards,

Håkon

RE: Not able to read IMU data.

NRF52833 — Thu, 02 May 2024 10:33:32 GMT

I even tried to flash sample twi scanner code with 100KHz mode. But its not detecting any accelerometer on the SDA/SCL pins.

RE: Not able to read IMU data.

NRF52833 — Thu, 02 May 2024 10:05:33 GMT

Hi,

Thanks for your reply.

Actually I have DWM3001CDK development kit which has DWM3001C module on board. So all I can do is only with the internal resistors on SDA//SCL pins. So do you have any other idea to get the data from lis2dh12 accelerometer

RE: Not able to read IMU data.

Håkon Alseth — Mon, 29 Apr 2024 11:42:30 GMT

Hi,

I see that you're using 400 kHz mode. The internal pull resistors are too weak to be able to drive this.

Do you have external pull resistors in the range of ~5 kOhm on your SDA/SCL pins?

Kind regards,

Håkon