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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
Associate II

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.

16 REPLIES 16
Jérémy Da Silva
Associate II

Any other idea?

Miroslav BATEK
ST Employee

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
Associate II

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
ST Employee

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).

Jérémy Da Silva
Associate II

Hi,

I have the same behavior...

Daniel.J
Associate

Hi,

@Jérémy Da Silva​ , did you solve your problem?

I'm having what I guess is a similar problem.

When I put the accelerometer in power-down mode it starts consuming way too much power(~650 uA).

If I put it in low power mode it goes down to ~10uA(the whole system).

I'm figuring it has something to do with pin states as you've discussed.

Is it okay to have CS_X pins tied to VDD?

I've tried that in combination to pulling I2C pins high/low without success.

EDIT: I just solved my problem, the solution was to put the INT_MAG signal to a pullup.

Miroslav BATEK
ST Employee

OK, this is what I recommended in the thread.