Motion tracking, specifically the MPU-6050 from invensense, a=20
combination 3-axis accelerometer and 3-axis gyro.  Most of them were=20
totally dead, some responded to configuration commands but produced zero=20
or crazy motion data.

J



Kardasinski, Milosz wrote:
> Motion tracking MEMs devices or microphones?
>
> -----Original Message-----
>
> Hi all, to elaborate a little further, 30 out of 30 1st-article pcbs
> with the invensense MEMS were destroyed by ultrasonic cleaning of
> the pcb.  100% failure rate of a relatively small sample I suppose
> statistically but way larger than one wants as an engineer trying to
> finish a project.  :)  The Invensense datasheet warns about this as
> I recall.
>
> I have heard the ultrasonic welding of cases causing grief with MEMs
> and xtals, as people have discussed.  For this project, there are 4
> very small self-tapping screws to close the case, no welding.
>
> That said, pretty clearly other wearable bluetooth devices
> (requiring at minimum an xtal in the 16-32Mhz range, and often a
> 32.768Khz as well if it is bluetooth low-energy) are welded shut.
> What devices like the Fitbit and the like (MEMs and xtals) do would
> be interesting to know. Presumably they have reliably solved the
> ultrasonic damage issue.
>
> J
>
>
--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.