I2C clock cannot be set to 10kHz

[DX_HK]

I am trying to communicate with an I2C device using an nRF52840.
I want to remove the external I2C pullup, so I want to reduce the communication speed to 10kHz.
However, the overlay clock speed cannot be set below 100kHz (it will be treated as an incorrect parameter and will result in a build error).
The slow mode of the I2C protocol is 10kHz, so this should not be treated as an error.

I'm sure this should be fixed at some point, but for now I just want to get it working.
How do I set the I2C clock to 10kHz?

[Vidar Berg]

Hello,

The lowest frequency we list as supported in HW is 100 Hz (TWIM). You may experiment with lower values in the FREQUENCY register, but it is not guaranteed that the peripheral will be able to meet the timing requirements set by the i2c specification. Have you calculated how strong pull-up you need to determine whether you can use the internal ones or not?

Best regards,

Vidar

[DX_HK]

Is there a setting in Zephyr that allows this?
Or is there an API that does this?

[Vidar Berg]

The driver only supports the frequencies listed in the FREQUENCY register. To use other values, you need to patch the driver.