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startup for the LIS331DLH accelerometer

rangineni34
Associate II
Posted on November 28, 2013 at 07:09

hi guys,

i am working with the LIS331DLH accelerometer, i was able to read the product ID but when i am going to set the config register 1  i am not getting acknowledgement, what may be the cause?

#lis331dlh
4 REPLIES 4
Thiago REIS
Associate II
Posted on November 29, 2013 at 17:18

Hello,

In order to better answer your question, would you be able to provide your registers configuration and also the schematic of the board that you are implementing this accelerometer?

Thank you,

Thiago Reis

rangineni34
Associate II
Posted on December 03, 2013 at 07:54

now, i am getting the output, i am able to set the control register properly, i am using Little endian format and i am recieving some data from the OUT registers, i am in a slight confusion how to interpret that data, i know the data is in 2's complement form -- this is the data i recieved when i placed x-axis facing earth 0x0350 and x-axis facing sky 0xff60, my problem is as we have to recieved negative data when x-axis is facing earth, here i am recieving +ve value, how to analyze and utilise that data? in my case even without moving the data i am seeing change in the sensor output only in LSB part, what is the cause and how to minimize it?                                                                                                                                                                                              In application note you specified 0x10h for 250mg threshold, if i want to use different threshold how to calculate that value

 

Thiago REIS
Associate II
Posted on December 05, 2013 at 17:24

Hello,

In order to have the acceleration measurements correctly there are two types of configuration that you have to consider:

- With High Pass Filter - This eliminates the gravity measurement from the sensor and only tilting and linear acceleration will be displayed

- Without the High Pass Filter - In this case you will always see the gravity acceleration distributed through the 3 axis depending on your devices positioning.

One other important point is that if you are finding acceleration values opposite than what you were initially expecting, you can either transform what is positive into negative and vice versa, or to place the sensor in the correct orientation, section 1.2 of the attached datasheet shows the axis orientation for this sensor.

Could you also please post the application note that you are referencing?

Thank you,

Thiago Reis

rangineni34
Associate II
Posted on December 19, 2013 at 08:26

thanks for your reply,

check the attachment, i am using this application note,

now i am going to work with the interrupts and with the HP filter, in this case i am still in confusion how to set the threshold value, as in your application note you are setting 0x10h for 250mg, how to convert G value to the hex and vice versa in order to set threshold?

could you tell me how to find out the G value from the obtained data?

i am in still confusion regarding that one!

________________

Attachments :

lis331dlh_application_note.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzB1&d=%2Fa%2F0X0000000bK5%2FkoKIm_3xIv4lj2DiRFC2GPQmAWyGBj0fZJWI8M1WwBM&asPdf=false