Hello, I work on a product with LSM303AGR and STM300 module. The problem is : when the LSM303AGR goes to sleep, it works. After, I try to get EnOcean module to sleep, then the LSM303AGR consume 500µA. Any idea?

[Jérémy Da Silva]

The SPI works well. I can asleep the sensor but when I try to asleep the EnOcean module, I see that the sensor consume near 500µA. I have put two pull down on SDI/SDO and SCL and two pull up on the CS_ACC and CS_MAG.

[Miroslav BATEK]

Can you share your schematic?

I don't know STM300 module, but why do you put pull down on SDI/SDO and SCL pins?

[Jérémy Da Silva]

Because the STM300 module pins are floating when it is sleeping

[Miroslav BATEK]

OK, I see.

The problem could be caused by floating INT_MAG/DRDY pin. Please try to connect pull-up or pull-down on this pin.

[Jérémy Da Silva]

I cannot pull up or pull down because the pin is inaccessible.. see below

I have tried to connect a STM32L151CC with the LSM303AGR and I don't have the power consumption problem. I think this pin can be left floating without having any influence on the power consumption.

[Miroslav BATEK]

Other solution could be set the INT_MAG bit in CFG_REG_C_M to 1.

[Jérémy Da Silva]

Done but I have the same power consumption.

[Jérémy Da Silva]

Any other idea?

[Miroslav BATEK]

Considering the high current consumption is only when the EnOcean module is in sleep mode and the GPIO are probably in high-Z, the problem could be cause by undefined level on the CS pins. The pull-up 10M are very week. You can try to decrease the value. But it is just my idea.

Btw. are you sure the high current is drawn by LSM303AGR?

[Jérémy Da Silva]

Hi,

I have decreased the value of the pull-up resistors but nothing happened.

I'm sure that high current is drawn by LSM303AGR because I have put one ammeter on the VCC of the EnOcean module and another of VCC of LSM303

[Miroslav BATEK]

I don't know which value of the pull-up you used, but please try following:

Put two 10k pull down resistors on SDI/SDO and SCL and two 10k pull up resistors on the CS_ACC and CS_MAG. Input pins must always be driven high/low (no floating).