description of gesture callback

By jeik , 19 June 2013
Forums
SmartMotion® MEMS Motion Sensors

Sorry, but I didn't find any explanation for your DMP. Where is it?
One question right now:
In decode_gesture(*gesture) I get
gesture[1] = 4 regularly,
but in your SDK there are only
#define INT_SRC_TAP (0x01)
#define INT_SRC_ANDROID_ORIENT (0x08)

defined.
Also, is there are a big delay in the output of FIFO? I want to record the
acceleration values in realtime, but changes come very late (> 1 second).

regards,
Steffen

beat

12 years 9 months ago

Hi Steffen

I have been having similar issues.
The lag when using the DMP FIFO has puzzled me for weeks.
I have been sending raw accel, calibrated gyro, tap and android orient to the FIFO.
Yesterday I noticed that the lag seems to vanish from my prototyping setup if I stop sending the tap and android orient data.
I would like to be able to use the DMP for tap detection but the lag is prohibitive.

Thanks
Elliot

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jeik

12 years 9 months ago

Hi,
the problem with the lag was in my testbench on the pc.
I have some plotting and it lasts to long.

But anyway, is there a description of the outputs of the DMP, especially
the gestures?

regards,
Steffen

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23280

guy_mcilroy

12 years 8 months ago

Please take a look at the API specification for the project you are working with. MotionDriver or the eMPL version. There can be some changes with supported DMP features, so the document should be the source of available tap / shake / orientation / pedometer / etc. available. Regarding the FIFO, there is no inherent delay, other than the rate at which the FIFO is read. Data will be stored within the FIFO when captured, and typically the FIFO will be cleared by your host controller at some slower rate. You can configure the rate to be closer to your desired operation speed to reduce the latency.

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