I need to work on twi compatible with smbus and I2C for NRF5340 DK

[Mr.NCK]

I need to interface my sensors by using twi. Here one of my sensor is smbus compatible. For I2C, I need to read acknowledge from sensor. So i need reference or samples to work on above requirements with NCS v1.5.0 for nrf5340dk

Thanks & regards

Navin

[Simon]

Check out this DevZone case: https://devzone.nordicsemi.com/f/nordic-q-a/63687/nrf52811-i2c-compatibilty

It seems like the sensor should be compatible with I2C as long as you set the speed to 100kHz. Use the clock-frequency field in an i2c instance to configure the speed (see thingy91_nrf9160_common.dts and dt-bindings/i2c/i2c.h).

Best regards,

Simon

[Mr.NCK]

Hi Simon,

Thank you very much, I have seen your ncs tutorial series that is very helpful. to get started to create an application nrf5340. I have understood part 1 and part 2.  I have got stuck at Part 3. It was a little difficult. give some implementation examples.

I have tried to interface the sht20 sensor with nrf5340. My sensor output values are always constant. even I didn't connect my sensor it throws the same values.

do you have any reference to interface external sensors other than given samples?

Simon said:

It seems like the sensor should be compatible with I2C as long as you set the speed to 100kHz. Use the clock-frequency field in an i2c instance to configure the speed (see thingy91_nrf9160_common.dts and dt-bindings/i2c/i2c.h).

I have tried the above. The same issue followed which I mentioned above.

Thanks & Regards

Navin

[Simon]

Mr.NCK said:

I have tried to interface the sht20 sensor with nrf5340. My sensor output values are always constant. even I didn't connect my sensor it throws the same values.

do you have any reference to interface external sensors other than given samples?

It seems like you are creating the driver yourself. I would recommend you to start with the i2c_scanner example, and just see if you can communicate with the sensor. Then you can gradually, step-by-step, build on the example. Write to a register, read a register, read sensor values. Study the datasheet of the SHT20 closely.

Do you have a logic analyzer? That's a very useful tool that allows you to see what's actually being sent.

Best regards,

Simon

[Mr.NCK]

Simon,

Thank you for your response.

Simon said:

I would recommend you to start with the i2c_scanner example,

I have tried i2c_scanner_example.

I can't able to read the device address. I have attached my output terminal below

Thanks & Regards

Navin

[Simon]

I made some modifications to the i2c_scanner sample:

• Changed the name nrf5340pdk_nrf5340_cpuappns.overlay to nrf5340dk_nrf5340_cpuapp.overlay
• Removed unecessary Kconfigs from the prj.conf
• Swapped NRF_TWIM1_NS with NRF_TWIM1_S

Could you test the updated sample with NCS v1.5.1 and the board nrf5340dk_nrf5340_cpuapp?

i2c_scanner.zip

Connect the sensor in the following manner:

Sensor	nRF5340 DK
SDA	P1.02 (34-32=2)
SCL	P0.04 (4)
VIN	VDD
GND	GND

I tested the sample with a MAX4009 GY-49 and it worked fine. I got the following output:

*** Booting Zephyr OS build v2.4.99-ncs2  ***                                                                                                                               v2.4.99-ncs2  ***
The I2C scanner started
Value of NRF_TWIM1_S->PSEL.SCL : 4
Value of NRF_TWIM1_S->PSEL.SDA : 34
Value of NRF_TWIM1_S->FREQUENCY: 26738688
26738688 -> 100k
0x4b FOUND

Best regards,

Simon

[Mr.NCK]

Hi Simon,

Thank you, Now I can read address

I have attached the Output image for your reference. I can read the address of the MPU6050 sensor. But I can't able to read the address of the  SHT20 and MLX96401. 

Regards, I have tested with the Logic analyzer. I have got a read timeout error.

Thanks & Regards

Navin

[Mr.NCK]

Hi again

I can't able to read the address of the Sht20 and mlx96401 sensor by using twi scanner. what can I do next ?

Thanks & Regards

Navin   

[Simon]

Mr.NCK said:

I can't able to read the address of the Sht20 and mlx96401 sensor by using twi scanner. what can I do next ?

Can you upload an image of the logic analyzer trace when you do this, then I can take a look at it.

Could you also attach the code you're using?