LSM303C abnormal power consumption and acceleration module breaking down

[yanqin gem]

Posted on May 21, 2018 at 12:15

Hi, ST

    We met some problem when used LSM303C. We operated LSM303C go to power-down mode after the module power on . 

Generally , the LSM303C current consumption is about 6 uA which is

consistent

with the datasheet e

lectrical characteristics

 table. But sometimes the 

current consumption would increase to 48 uA after the module power on. And it seems that the acceleration module didn't work well for reading  a

ccelerometer Who_AM_I register to get 0x00 but not 

 0x41.  What may cause this phenomenon. Please give us some guide advice.

     Our operating codes are as follow:

void LSM303C_Init(void)

{

I2C_WriteOneByte(lsm303_acc,LSM303C_CTRL_REG5_A, 0x40);//Soft reset

user_delay_ms(10); I2C_WriteOneByte(lsm303_acc,LSM303C_CTRL_REG6_A, 0x80);//Force reboot user_delay_ms(5);

I2C_WriteOneByte(lsm303_mag,LSM303C_CTRL_REG2_M, 0x0c);//Reboot memory content, And register reset

user_delay_ms(10);

I2C_WriteOneByte

(lsm303_acc,LSM303C_CTRL_REG1_A, 0x00);//power down

I2C_WriteOneByte

(lsm303_mag,LSM303C_CTRL_REG3_M, 0x03);//power down

}

#power-consumption #lsm303c

[Miroslav BATEK]

Posted on May 22, 2018 at 21:01

Can you share your schematic?

[yanqin gem]

Posted on May 23, 2018 at 03:57

hi,  Microslav B

    this is our schematic.

[Miroslav BATEK]

Posted on May 23, 2018 at 16:32

The CS_XL and CS_MAG cannot be let floating, for I2C communication they must be connected to VDD_IO.