How to put lis2dw12tr in power down?

Forum|Forum|4 years ago
September 10, 2021
4 replies
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Hi im using lis2dw12tr sensor with I2C protocol in my app and i configured sensor in powerdown CTRL1 register i writed 0x00.

But i see that on the board on which sensor is placed has current consumption around 370uA. On the board with unmounted sensor current consumption is 2.5 uA. Code on both board is the same.

I also tried to configure in CTRL2 register CS_PU_DISC to "1" (default is "0"). I have external pull-up resistors on SDA and SCL lines (10k). Schematic is used from sensors datasheet (Figure 6. LISDW12 electrical connections).

Do I must also to change some values in register CTLR3 (PP_OD, LIR, H_LACTIVE) from "0" to "1"?

Is it verification board for the LIS2DW12TR this board STEVAL-MKI179V1?

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Best answer by MKla.1

@Eleon BORLINI Thnak you. The problem was because the 3rd pin is tied to GND.

Can you please little explain how it works stationary/motion detection works.

Similar graph like it is for activity/inactivity and is it enough to put the STATIONARY bit to "1" + settings for activitiy/inactivity to put sensor in stationary/motion detection mode?

M

MKla.1Author

Visitor II

Is it possible that the reason of that big current consumption because od the 3rd pin of the sensor is tied to GND?

E

Eleon BORLINI

ST Employee

Hi @Community member ,

please have a look to this similar thread.

The SDO/SA0 pin is internally pulled up, and this means that there could be a resistance path causing the current to flow down from 3V3 to 0V through it. You can try disconnecting this pin, if you can, an check whether the overconsumption comes from here.

-Eleon

M

MKla.1AuthorAnswer

Visitor II

@Eleon BORLINI Thnak you. The problem was because the 3rd pin is tied to GND.

Can you please little explain how it works stationary/motion detection works.

Similar graph like it is for activity/inactivity and is it enough to put the STATIONARY bit to "1" + settings for activitiy/inactivity to put sensor in stationary/motion detection mode?

K

KWine

Visitor II

If you use LPower1 mode at 1.6 Hz and stationary bit set to 1 you can get wake-on-motion and sleep-on-no-motion behavior at about 0.55 uA as I measure it. So it works the same as activity/inactivity just when there is no activity the sensor does not default to 12.5 Hz as when stationary bit is left at 0. rather, the sensor stays at 1.6 Hz LPowerMode1, which is the lowest power state, whether awake or asleep. Pretty cool!