Mems Detected automatically for certain range of threshold..........

[shanmugasundaram]

hi,my mems device was detecting automatically for certain range of threshold between 1 to 16 value.i use calibration of X and y axis and i change debounce value also.how can i fix that...?

[shanmugasundaram]

hello hi,

Thank you for your kind reply.

I am using MMA8653FC  motion/ free fall sensor . In that I  use motion detection and I set threshold value 16 then i place my device ideally in flat surface . In this scenario I getting automatic interrupt without any movement in device. I cant share the source code because of company policies but I share configuration settings.Below there are

Reg               Value

0X2A              0X58

0X2b              0X1C

0X2C             0X02

0X2D             0X14

0X2E             0X14

0X15              0XF8

0X17              0X25

0X29              0X05

0X11               0X40

0X12               0x01

 Apart from this registers,I tried Debounce and calibration registers and there is no improvement ,so kindly tell me "how to fix the motion auto detection in ideally state".Thank you

[TomasVaverka]

Hello,

Does it also happen if you increase the motion threshold to greater than the acceleration from static orientation (gravity, 1g). It might be better to use the embedded transient detection function that compares whether any of the enabled axes has exceeded a set change in acceleration disregarding the static acceleration (gravity). For more information including example codes please take a closer look at AN4071 and AN4070. You might also find useful this example code.

Best regards,

Tomas

[shanmugasundaram]

Hello  hi,

As I already mention I am using MMA8653FC chip.In that no transient detection and tap detection feature .I can use motion/free fall and oriention only. I need to detect when slow motion applied. sometime when device in threshold 17 , i have to apply more force to get  detection and tell me how to avoid auto detection ,when the threshold value is between 0-15.Thank you

[TomasVaverka]

Hello,

I am not sure if I can fully help here because you are not very specific on what the issue is. Could you please elaborate it a bit more and post here your source code to better understand the problem you are facing?

Best regards,

Tomas