What accelerometer is used in the LSM330DLC?

Bob Paddock · ‎2018-02-06

Posted on February 06, 2018 at 16:45

It is my understanding that the LSM330DLC is a 'System-In-Package', that is it is a separate accelerometer and gyro die packaged together. What are the actual die part numbers?

The reason I ask is that the LSM330DLC is rather spares on explanation of what the various bits in the registers do. Bit wise the bits seem to match the LIS3DH, however the actual register addresses are different.

Also the LIS3DH has the Block Data Update (BDU) feature to safely read the multi-byte (10 and 12 bit) data registers, where the LSM330DLC says not to enable this. How can the mutil-byte data be safely read without corrupted readings?

The bottom line question is what other supporting documentation is there for the LSM330DLC? LIS3DH and AN3308 seem close, however are not an exact match.

#lsm330dlc

Miroslav BATEK · ‎2018-02-06

Posted on February 06, 2018 at 20:51

Hello Bob,

firts of all the LSM330DLC is obsolete sensor, with NRND (not recomended for new design) status. So I recommend you to use some modern sensors, which has better performence, software support and documentation. You can use for example

http://www.st.com/content/st_com/en/products/mems-and-sensors/inemo-inertial-modules/lsm6dsl.html

.

The LSM330DLC can be similar to some other sensors, but I reccomend you to use only docuemtnation for the LSM330DLC to avoid problems.

To safely read multipre registers, you have to read the fast enough (before new data are available) and synchronize your reading with data ready signal.

Bob Paddock · ‎2018-02-06

Posted on February 06, 2018 at 21:27

Miroslav B wrote:

Hello Bob,

firts of all the LSM330DLC is obsolete sensor, with NRND (not recomended for new design) status. So I recommend you to use some modern sensors, which has better performence, software support and documentation. You can use for example

/external-link.jspa?url=http%3A%2F%2Fwww.st.com%2Fcontent%2Fst_com%2Fen%2Fproducts%2Fmems-and-sensors%2Finemo-inertial-modules%2Flsm6dsl.html

.

The LSM330DLC can be similar to some other sensors, but I reccomend you to use only docuemtnation for the LSM330DLC to avoidproblems.

To safely read multipre registers, you have to read the fast enough (before new data are available) and synchronize your reading with data ready signal.

Not using it is NOT an option. I've inherited four hundred boards that already have it on it and Management wants them working and shipped. :(

I would be happy to use only LSM330DLC documentation. Where is it?

LSM330DLC register documentaiton is not in the data sheet document Doc ID 022162 Rev 2.

Lets take a couple of concrete examples. In CTRL_REG3_A (22H) what is I1_DRDY2? In CTRL_REG6_A (25H) what is I2_BOOT? ; Some other documented indicated this could be used to tell when BOOT was complete???

I sure hope the LSM6DSL has better documentation and longer life expectancy... For now I'm stuck with this LSM330DLC.

Thank you for the help.

Miroslav BATEK · ‎2018-02-23

Posted on February 23, 2018 at 13:08

There is no other documentation than

http://www.st.com/content/ccc/resource/technical/document/datasheet/bd/61/af/53/b5/f5/4d/7b/DM00037200.pdf/files/DM00037200.pdf/jcr:content/translations/en.DM00037200.pdf

.

I1_DRDY2 in CTRL_REG3_A should be kept equal to 0, it is a error in the datasheet.

I2_BOOT in C

TRL_REG6_A allows you to indicate finished boot-up of the device on INT2 pin.

Bob Paddock · ‎2018-02-23

Posted on February 23, 2018 at 14:08

So the datasheet is both incomplete and untrustworthy.

Wonderful.

Any other errros in the datasheet I should know about?

Thank you for your help.

Miroslav BATEK · ‎2018-02-23

Posted on February 23, 2018 at 15:57

Hello Bob,

I'm not aware about any other errors.

Frankly, I'm not responsible for the datasheets but I'm trying to help you. We are only humans and sometimes we make a mistakes.

The two bits which you mentioned are not crucial. Anyway if something else want be clear let me know.

Bob Paddock · ‎2018-02-23

Posted on February 23, 2018 at 19:25

I do thank you for your help, no one else even thought it was worth their time to respond.

I'll make sure that when other people design the hardware that they pay more due diligence to looking at what is avalaible for writting the software, rather than just make me clean up the mess and be the fall guy for the project being late due to bad/missing documentation.