VL53L7CX Motion power

[LudovicB]

Hi,

I'm trying the VL53L7CX sensor for a prototype and I'm trying the example codes provided within  this page https://www.st.com/en/embedded-software/stsw-img036.html

I'm experimenting the Example_10_motion_indicator and I'm able to display the "motion power" of the 16 zones within a 10-iteration loop. I just can't figure out what the results mean ! Even when the sensor is totally masked (I mean, physically), the Motion powers seem to start at 0 for all zones (which looks relevant) and increase to apprently random values up to 50-something. Lacking information from the datasheet, I wonder how to use this data and what is its signification.

Thanks for your help!

[John_Kvam]

I trying to find more, but... It's a measure of how much the histogram data changed, and the algo was looking for people as they approached. I'm guessing 50 is a pretty low number. (64 zones each dithering by 1mm could well add up to 50.)

So, try this. Run the algo and approach the sensor. See what kinds of numbers you get. Are they in the thousands or even tens of thousands?

If so, find a limit above which you can reasonably assume motion. 

And if I get more info, I'll post again. 

- john

[LudovicB]

Hi. Thanks for your reply. I tested the sensor again and it actually appears that mesurements in the range of several tens is just noise and that significant values are of the order of magnitude of a few thousands. I hardly reached 10,000. I could be interested in having more info about the algorithm and the signification of these measurements (can we relate them to speed linearly?).

Thanks again and I look forward to any further available details.

Ludovic