Hi Edyta

 

Your code doesn’t show what value you used for I2C_ADDR. You will not get an ACK on the I2C bus if you have the wrong I2C addr for the LSM3DS33. Without an ACK, you get a bus error.

 

I think your I2C_ADDR should be 0x6B.

 

The WHO_AM_I register in the  LSM3DS33 is 0x0F, not 0xF0.

 

Lawrence King

Principal Developer

+1(416)627-7302

 

From: users@... <users@...> On Behalf Of Edyta Bosacka
Sent: Thursday, July 23, 2020 9:35 AM
To: users@...
Subject: [Zephyr-users] Reading data from LSM6DS33 , I2C

 

I am trying to get Who I am data from accelerometer LSM6DS33, but I cannot receive them.  I' m getting this error: I2C transfer errorI am: 0. What can be the reason of this? 

 

#define LSM6DS33_XG_WHO_AM_I_ADDR                            0xF0

 

static int i2c_read_byte(struct device *i2c_dev_0, uint8_t *data, uint32_t num_bytes, uint16_t addr ){

 

    uint8_t wr_addr;

    struct i2c_msg msgs[2];

    

    /*Register addres*/

    wr_addr = addr;

 

    /*Setup I2C messages*/

 

    /*Send the address to read*/

    msgs[0].buf = &wr_addr;

    msgs[0].len = 1U;

    msgs[0].flags = I2C_MSG_WRITE;

 

    /*read from device*/

    msgs[1].buf = data;

    msgs[1].len = num_bytes;

    msgs[1].flags = I2C_MSG_READ | I2C_MSG_STOP;

 

    return i2c_transfer(i2c_dev_0, &msgs[0],2, I2C_ADDR);

 

}

 

 

//Read Who i am

    data[0] = 0x00;

    int err = i2c_read_byte(i2c_dev_0, &data[0], 1, LSM6DS33_XG_WHO_AM_I_ADDR);

    if(err){

        printk("I2C transfer error");

    }

    printk("I am: %s \n", data[0]);