SHT25 interface with nordic

[Mr.NCK]

Hi,

I am Using nrf52832DK and SHT25 breakout board. I can't able to read a device address using "TWI Scanner". But, I can able to scan the sht25 device address by Arduino I2c scanner.

I need your help to make work nordic's TWI Scanner for the sht25 breakout board or suggest me the code for the proper interface of sht25 with nrf52832.

[awneil]

Mr.NCK said:

I am Using nrf52832DK and SHT25 breakout board

What "breakout board" are you using?

Show a schematic of how you have connected them together.

Have you checked basics - like pullups?

Have you checked against the datasheet: 

www.sensirion.com/.../Sensirion_Humidity_Sensors_SHT25_Datasheet.pdf

Have you used an oscilloscope to see what's actually happening on the wires?

See: https://devzone.nordicsemi.com/f/nordic-q-a/72492/error-in-establishing-a-connection-between-nrf52840-dk-board-and-sht21-sensor-using-twi-module

[Mr.NCK]

thanks 

1) https://www.evelta.com/evelta-sht25-i2c-temperature-and-humidity-sensor/

2) I have just connected the SCL and SDA pin of the breakout board with nrf52 dk pin 27 And 26

3) that is Breakout right??

4) kindly guide me on what are the things. I need to check

5) I don't have oscilloscope

[Mr.NCK]

Online Mr.NCK 20 hours ago

Hi Karl

      We have just use the nordic  TWI scanner we didn't change anything in code only change the pins and we didn't have the breakout board datasheet. We have only the Sht25 SOS datasheet

Thank you

[Karl Ylvisaker]

Hello,

It is unfortunate that you do not have the breakout board's datasheet. From the SHT25 datasheet I read that it needs to be supplied with external pullups, but we do not know whether the breakout board does this or not.
Could you check whether the Arduino configures pullups on the pins as part of the test you did where it worked? As in, check whichever TWI driver and peripheral you used on the Arduino, and see if it sets pullups, or assumes external pullups.

Karl Ylvisaker said:

Would you mind sharing the code section where you setup and configure the TWI peripheral?
It would also be helpful to see the changes you have made to the boardfile. 

You mentioned that you have made some changes to the board file / example, it would be helpful to see these.

Is there any chance you could get access to a logical analyzer?
Seeing what is actually happening on the lines would make this debugging (and any other serial protocol debugging) much easier.

Best regards,
Karl

[Mr.NCK]

Hi Karl 

I will check the possibilities and made the requirements. then again continue here.

Thank you

[Mr.NCK]

Hi Karl 

I have checked with Arduino I2C Scanner they are using internal pullups by using a wire library. Tell me how can we activate the internal pullups for nrf52.  

Thank you

[Karl Ylvisaker]

Hello again,

Thank you for checking and clarifying.

If you look into the initialization of the TWIM pins, it too enables pullup on these two lines by default.
It would therefore be very helpful to see what is happening on the lines directly. Do you have access to a logical analyzer, like I asked about in my previous comment?

It would also be helpful to see the changes you mention that you have made to the boardfile, like I asked for in my previous comment. Additionally, seeing the actual schematics for how you have connected all your wires (a diagram, not a text description) would also be beneficial, if possible.

Looking forward to resolving this issue together!

Best regards,
Karl

[Mr.NCK]

Hi Karl,

By using a logic analyzer, rewrite the code and successfully get the output.

Thank you for your help and thank you awneil.

Thanks & Regards

Navin

[Karl Ylvisaker]

Hello again Navin,

Mr.NCK said:

By using a logic analyzer, rewrite the code and successfully get the output.

I am happy to hear that you were able to get it working as intended!

Mr.NCK said:

Thank you for your help and thank you awneil.

No problem at all! :)

Please do not hesitate to open another ticket if you should encounter any issues or questions in the future.

Good luck with your development!

Best regards,
Karl