Error setting sampling frequency on lsm6dso - nrf52833

[ReginaA101]

Hi all,

I am running the lsm6dso zephyr sample on my nrf52833 dev kit. I am unable to set the sampling frequency. I get this error after flashing:

This is my overlay file:

My SDK version is 2.7 and I am on Zephyr 3.6.99

My debugger suggests that the issue could be from this case failing in i2c_nrfx_twim.c

However, the IMU address is listed at 7 bits long in the datasheet.

Does anyone have any suggestions?

[Håkon Alseth]

Hi,

 

Try setting "accel-odr" member:

https://github.com/nrfconnect/sdk-zephyr/blob/v3.7.99-ncs1/dts/bindings/sensor/st,lsm6dso-common.yaml#L17

 

Also, I would recommend that you run on 100 kHz first, as 400 kHz requires stronger pull resistors (ie. external pull present).

 

Kind regards,

Håkon

[ReginaA101]

Also, I get an error code -22 whenever I try to set the sampling frequency for the LSM6DSO

[ReginaA101]

Yes i am running that example.

This is the scope 

However, when building the project with this device tree

I get this warning:

I assume this means that lsm6dso has to be enabled in the device tree. But it seems like i marked it as a compatible so it should be fine. Are there any ideas? 

[Håkon Alseth]

Hi,

 

Q1: Can you please share the full build output?

Q2: Can you share the overlay as a file? The warning that you attached indicate that the overlay is not picked up by the build-system.

 

Kind regards,

Håkon

[ReginaA101]

That was the build output

The overlay file is here:

0636.nrf52833dk_nrf52833.overlay

[Håkon Alseth]

Hi,

 

I tested this on my system, as well as a colleague of mines setup, and we are not able to reproduce the line "warning: LSM6DSO was assigned the value 'y', but got the value 'n'", which is effectively not including the driver into your build.

 

Can you delete your build-folder and regenerate the build?

Your overlay, when matching your board, will be automatically appended, so your build in vscode shall look like this:

 

Kind regards,

Håkon

[ReginaA101]

Is there any other configs you need besides config_lsm6dso and config_i2c?

[Håkon Alseth]

The sample is unchanged, just added your file to the folder-structure.

 

Kind regards,

Håkon

[ReginaA101]

I redid my build, and the config error went away. Thanks for that

However I am still unable to communicate with my sensor.

This is my scoping of the SDA and SCL pins. The pins sit at high, then when I restart the board thats when both the pins go low, then they sit at high continuously. 

I am using the same sample https://github.com/zephyrproject-rtos/zephyr/tree/main/samples/sensor/lsm6dso I just changed one line in main due to getting a "device not ready" error:

This is my proj.conf file:

And the overlay file is the same one I sent a couple days ago

This is the sensor board I have

https://www.st.com/en/evaluation-tools/steval-mki217v1.html

Is there any possible configurations I could be missing to enable i2c communication? I have verified the connection of SDA/SCL/VDD and GND pins.

Thanks for your time

[Håkon Alseth]

Hi,

 

Please note that zephyr supports lsm6dso, and not lsm6dsox directly. I do not know the exact difference between the two sensors, but they seem to have a similar i2c address atleast.

 

If you zoom into the rising edge of your saleae logic trace at approx. +0.5 sec, you should see some i2c communication. Please share this, and check if the sensor ACKs.

 

ReginaA101 said:

This is the sensor board I have

https://www.st.com/en/evaluation-tools/steval-mki217v1.html

Is there any possible configurations I could be missing to enable i2c communication? I have verified the connection of SDA/SCL/VDD and GND pins.

There is two sensors on this board, you will have to make sure that the board itself is not modified, as the default is to have both sensors connected over the common i2c lines.

ReginaA101 said:

I am using the same sample https://github.com/zephyrproject-rtos/zephyr/tree/main/samples/sensor/lsm6dso I just changed one line in main due to getting a "device not ready" error:

It seems like you have changed this line:

https://github.com/zephyrproject-rtos/zephyr/blob/main/samples/sensor/lsm6dso/src/main.c#L111C53-L111C63

 

I would strongly recommend that you keep this "as-is", ie. revert your change, as this line is crucial in terms of initializing and using the lsm6dso sensor driver.

 

Kind regards,

Håkon

 

[ReginaA101]

Thanks for your suggestions 

I have reverted the change

I am still getting a device not ready error.

I zoomed into the section you told me and I am getting an initialization. Seems that the first 7 bits are 6A which was the i2c address I believe.

It doesnt seem like I am getting any ACK though

[Håkon Alseth]

Hi,

 

Your sensor does not ACK (ie. NAK), as the LSBit in the transaction is high, indicating that there is a problem on the sensor side.

 

You should go over your physical connection and see if there's anything that isn't properly connected (VDD, VDDIO, GND, SDA and SCL).

 

Kind regards,

Håkon