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Illuminance vs. distance with SensorTag
#7
Hey Sebastian, thanks for the Update!

Finally my Bluetooth Mouse 3600 arrived and i could do some tests myself. I modified the original "HID Mouse: Illuminance vs. distance (Bluetooth)" so it can be used with the SensorTag CC2650 - currently desperately trying to get the cc2541 up and running, but that's another topic.

The optical sensor of the cc2650 provides data each 800 milliseconds (default) but as we know the refresh rate of the mouse is considerably higher. This leads to multiple assignments of different distance values to one and the same illuminance value. A sleep rate, as Sebastian suggested, of 0.8 assigns one illuminance to one distance value. However, data may be lost in this case if the mouse is moved to fast. You can use no-sleep but then you probably have multiple distance values for each illuminance value and might treat the data later. Maybe I give the interpolation a try somewhat later.

The other file (TEST suffix) is more of a "work in progress" with more possibilities as part of a planned experiment cycle or student experiment. The idea is that the students see that illuminance and distance are somehow connected (the greater the distance, the lower the measured value) and to let the students make guesses how the illuminance corresponds to the distance (e.g. 1/r, 1/r^2, ... ). Instead of using the logX/logY for the grahp, i let phyphox evaluate every log because I want to calculate the exponent. Haven't figured that out yet and I'm not sure if this might be more of a bug than a feature. ;D

Anyway, it's nice to do the experiment with the SensorTag. Thanks to all who contributed to the original "illuminance vs. distance"-file!

Here are some screenshots, how the measurements (LED flashlight) with and without sleep rate differ (top is with sleep, bottom without sleep)


Attached Files Thumbnail(s)
   

.phyphox   HID Mouse Light - SensorTag.phyphox (Size: 7.22 KB / Downloads: 478)
.phyphox   HID Mouse Light - SensorTag_TEST.phyphox (Size: 10.63 KB / Downloads: 493)
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RE: Illuminance vs. distance with SensorTag - by SJS - 06-02-2020, 06:44 PM

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