I2C

RE: I2C

Einar Thorsrud — Wed, 26 Mar 2025 09:37:15 GMT

Hi,

I am glad to hear you resolved the first issue. When switching to the nRF Connect SDK I recommend going through the nRF Connect SDK Fundamentals course. This takes about a day, but will get you started with all the tools and the basic understanding of how to work with the SDK. At a later point, I also recommend going through nRF Connect SDK Intermediate which covers more advanced topics. Other than that, the SDK documentation is quite extensive.

RE: I2C

Himanshu_flexe — Wed, 26 Mar 2025 06:19:32 GMT

Hi,

thanks for the reply .

i resolve the isssue of SDA and scl not toggling , i am using nrf52840 DK , it was the issue in my code now i m am usimng P0.27 and P90.26 for SCL and SDA but stiil it is not able to detect my htdu sensor whose adress is 0X40 .
As suggested by you i will switch to nrf connect sdk , can you tell me or share me resources how to learn it efectively beacuse it take lot of time to me understnd it and sometime i get overwhelmed with the tyhing not working

RE: I2C

Einar Thorsrud — Mon, 24 Mar 2025 13:18:21 GMT

Hi,

First of all I would like to mention that if you are new to the SDK and that means that you are starting new development now, I would advice using the nRF Connect SDK instead of the old nRF5 SDK. See nRF Connect SDK and nRF5 SDK statement.

[quote user=""]When probing the SDA and SCL lines, both remain at 3.3V (high state).[/quote]

Can you disconnect the sensor and meaure on the pins directly just to verify that there is not an issue externally?

[quote user=""]Why is the SCL line not toggling?[/quote]

Good question. Can you share how you configure the pins so that we see that the correct pins are used? Are you using a custom board or the DK? If custom board, could it be that there is a soldering or some other routing issue? Do you have logging showing relevant information, and have you for instance cheked what is happening with a debugger?

[quote user=""]Do I need to configure any additional settings in sdk_config.h or modify my TWI initialization?[/quote]

Internall pull resistors are normally enough for lower speeds, but for higher speeds external pull resistors may be needed. That should not be the main issu ehere though, as you report measuring a constant high voltage as I read it.