I need help for nrf5340 with I2c

[Mr.NCK]

Hi,

I am trying to learn the I2c with nrf5340 PDK. I need to interface Sht20 and Mlx90614 with nrf5340PDK. I need to know the procedures regards this on NRF Connect SDK

Thanks & Regards 

Navin

[Albrecht Markus Schellenberger]

Thanks a lot for the feedback, Navin!

Could you please add:

CONFIG_CBPRINTF_FP_SUPPORT=y

to prj.conf and replace printf with printk?

Does that make any difference?

Regards,

Markus

[Mr.NCK]

Hey Markus,

After the changes have done which you are said. I can't able to open my project actually.

I have made some changes in my code and I got readings. But Readings from sensors are not varied. Can you help me regards?

for clear understandings, I have tried to rewrite the Arduino library code to nrf  I2C

 /**********Arduino Code***********\
 
 uint16_t result;

    Wire.beginTransmission(eSHT2xAddress);
    Wire.write(command);
    delay(100);
    Wire.endTransmission();

    Wire.requestFrom(eSHT2xAddress, 3);
    uint32_t timeout = millis() + 300;       // Don't hang here for more than 300ms
    while (Wire.available() < 3) {
        if ((millis() - timeout) > 0) {
            return 0;
        }
    }

    //Store the result
    result = Wire.read() << 8;
    result += Wire.read();
    result &= ~0x0003;   // clear two low bits (status bits)

    //Clear the final byte from the buffer
    Wire.read();

    return result;

I have tried to rewrite the above lines  to the below-mentioned code

const struct device *i2c_dev;

  uint16_t result;
  uint16_t buff[10];

  i2c_dev = device_get_binding("I2C_1");


   i2c_write(i2c_dev,command,sizeof(command), eSHT2xAddress);
     k_msleep(300);

  result = i2c_read(i2c_dev, buff, sizeof(buff),  eSHT2xAddress)<< 8;
   result += i2c_read(i2c_dev, buff, sizeof(buff),  eSHT2xAddress);
    result &= ~0x0003;

    return result;

 

Kindly, help me to get output.

Thanks & Regards

Navin

[Albrecht Markus Schellenberger]

Hello Navin,

So I guess that:

i2c_write(i2c_dev,command,sizeof(command), eSHT2xAddress);
     k_msleep(300);

requests data from the sensor? What is the command you are writing to this function? Could you please check the return value of its call?

My assumption at the moment is that the buffer is not updated with new values.

Regards,

Markus

[Mr.NCK]

Hi Markus,

Command = Register address;

its returns some value but not accurate

can you please tell me how to rewrite the below section for nrf?

  Wire.requestFrom(eSHT2xAddress, 3);
    uint32_t timeout = millis() + 300;       // Don't hang here for more than 300ms
    while (Wire.available() < 3) {
        if ((millis() - timeout) > 0) {
            return 0;
        }

this same issue follows for mlx90641 also.

Thanks & Regards

Navin

[Albrecht Markus Schellenberger]

Hello Navin,

with return value i meant the value that the function call returns and not the arguments of the function.

Does it return 0 or -EIO?

Regards,

Markus