FXLS90322 Get the NACK bit when write the device address 0x60

[Lin_SiuU]

Hi,

When i use the FXLS90322 with the I2C protocol,i write the slave address (0x60),and than i can`t get the ACK bit.

[TomasVaverka]

Hi,

One thing that is often neglected is that this 7-bit slave address (0x60 by default) must be placed in the upper 7 bits of the byte and the Read/Write bit is in the LSB. It means that to write to address 0x60, you must actually send out 0xC0 which is 0x60 moved over by 1 bit. To read from address 0x60, you must actually send out 0xC1 which is 0x60 moved over by 1 bit + 1 (R/W bit=1 for a read).

I hope it helps.

Best regards,

Tomas

[Lin_SiuU]

Hi Tomas:

Are there any Setting i must make before using the I2C communication Function of the FXLS90322?

I still cannot receive the ACK bit from the slave while writing the address(the address had already moved over by 1 bit).

From the time sequence captured by oscilloscope, the time sequence of I2C is also normal, but still can not receive the ACK bit sent from the FXLS90322.

I use S32K144 as MCU ，and the SDK Vision  is 4.0.2.

BTW,when I used FlexIO to simulate I2C communication, the error status I received was I2C_RX_Overrun

Looking forward for your reply.

@TomasVaverka 

[Lin_SiuU]

Hi Tomas，

    when i write/read the address,the upper 7 bit address has been moved over.Besides. when i measure the SCL and SDA voltage,i found that the SCL voltage is 4.7V which is lower than 5V.And when i add another I2C device to the I2C bus,the voltage of SDA has changed from 5V to 4.7,and for the SCL is 4.5V,But When use the FXL90322,the I2C Bus voltage is normal 5V.

Does this situation will lead to the unusual communication? And Do you know what reason will lead to the voltage drop?

Looking forward to your reply.