Help Initialization

[steffen]

Posted on November 07, 2013 at 17:35

Could you please give a overview how to initialize the chip. I miss a description of the diverse adjustments.

There are obvious errors in the Data-Sheet of

LIS331DL

.

I.e. HP_FILTER_RESET <-> HP_RESET_FILTER

     Where is the ''The H3LIS331DL features a data-ready signal (RDY)''

regards,

Steffen

#h3lis331dl-configuration #accelerometer #h3lis331dl #h3lis331dl

[steffen]

Posted on November 14, 2013 at 09:24

Hello,

is there a moderator?

I've found

stsw-mems004.zip

for the LIS331DLH

is this a startpoint?

regards

[Thiago REIS]

Posted on November 18, 2013 at 14:40

Hello Steffen,

I am one of the moderators of the MEMS Developers Corner, in order to better reply to your question, would you be able to provide more details on what kind of information you are looking for?

Are you currently using an evaluation board?

Please let me know what I can do to better support you,

Thank you,

Thiago Reis

[s239955]

Posted on November 18, 2013 at 16:39

Hi,

I read that and I have also a few questions.

I use the H3LIS331DL.

I have no testboard, I use the chip direct with an µC (LPC1857),

Are there any code examples ?

I communicate over SPI. It works. I can read and write data. Are they configuartion examples for a normal use?

Is it possible that the values X,Y and Z are left aligned in the output registers?

Should I make a 4 bit right shift with the 16 bit value, see below:

16bitvalue = (X_high_Byte <<8) | X_low_Byte;

16bitvalue>>=4;

Thanks

Stefan

[steffen]

Posted on November 18, 2013 at 16:55

Hello Thiago,

I had at least  4 questions:

What is the difference : HP_FILTER_RESET <-> HP_RESET_FILTER?

Where is the ''The H3LIS331DL features a data-ready signal (RDY)'' ?

Does stsw-mems004.zip work for the H3LIS331DL? At a first glance, it seems so.

Where is an explanation of the settings in the Chip ( HP-Filters vs. data rate) for practice?

I have only a datasheet only with register-description without at least a basic application for

the chip.

regards

Steffen

[Thiago REIS]

Posted on November 19, 2013 at 14:49

Hello Steffen,

Answering your questions:

What is the difference : HP_FILTER_RESET <-> HP_RESET_FILTER?

HP_FILTER_RESET:

Dummy register. Reading at this address zeroes instantaneously the content of the internal high-pass filter. If the high-pass filter is enabled all three axes are instantaneously set to 0

g.

This allows the settling time of the high-pass filter to be overcome.

HP_RESET_FILTER: Reffers to CTRL_REG2(21h), please check attached datasheet on page 25, section 7.3.

Where is the ''The H3LIS331DL features a data-ready signal (RDY)'' ?

Please check on the attached datasheet page 27, table 25, 25,

Does stsw-memszip work for the H3LIS331DL? Yes. it does work.

Where is an explanation of the settings in the Chip ( HP-Filters vs. data rate) for practice?

Please check page 26, table 23 and 24 of the attached datasheet.

Please do let me know if there is any other topic that you would like to discuss!

Thank you,

Thiago Reis

________________

Attachments :

H3LIS331DL.pdf : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006HzBv&d=%2Fa%2F0X0000000bKJ%2FVrsYGdd71AbZ60U4bvK2KZclZ9V4PuLnfdKMuR4fKNE&asPdf=false

[Thiago REIS]

Posted on November 19, 2013 at 14:55

Hello Stefan,

I do not have any coding example to post yet, but as soon as I get it, it will be posted on the forum.

Yes, you are right, the output of the H3LIS331DL is left justified.

Please let me know if there is anything else I can do for you.

Thank you very much,

Thiago Reis

[s239955]

Posted on November 20, 2013 at 12:28

Hi Thiago,

thanks for your response.

I can now read / write the H3LIS331Dl :)

But I have few questions!

In the Datasheet from the H3LIS331DL the ''TyOff Typical zero-g level offset accuracy'' with +-1g is described. What means this prameter exactly?

I read out the sensor data (Z,X,Y) with 100Hz and +-100g (no filter active) and if no acceleration appears the Z- axis have a value in the middle from 2000mg and with a noise approx. +- 500mg, the X and Y axis have in the middle 500mg with a noise approx. +-500mg. Is this noise correct?  I think I should activate the internal filter!? Have you examples how the filter should be configurated (best result)? Is the Z-axis so high because of TyOff with +-1g?

If I will measure accelerations, is it right that I have a tolerance from +-1g (without linearity,..) because of TyOff? How ist TyOff for the range +-200/400g? The same?

Thanks

Stefan

[Thiago REIS]

Posted on November 21, 2013 at 15:40

Hello Stefan,

With regards to the topics that you have mentioned, the typical zero-g offset that you might encounter should be around + -  1g, that means that the measurements that you have done are correct, this is only the normal variation of the component when working in the 100g FS.

I do have to check though the conditions for the other FS (200g and 400g), and as soon as I complete this I will post it to the forum.

In order to provide a better support to you and your application, could you please provide more details on what is the final application for this accelerometer?

Thank you very much,

Thiago Reis

[dhsu123]

Posted on March 05, 2015 at 08:49

Hi Thiago,

I’m having issues configuring the gyro on the lsm9ds0. I believe it has to do with the high pass filter settings. 

The Gyro outputs jump all over the place at default values. When i set CTRL_REG2_G “High PASS filter mode config� from the default 00 “Normal (Reset reading HP_RESET_FILTER)� to 10 “Normal� it seems to stabilize. What is the difference between these two settings?

thx,

David