VL53L1X offset calibration and xtalk calibration

[MOB1]

Hello I want to add a glass to my VL53L1X ToF sensor . How should I calibrate for using with glass?

I tried to calibrate with the help of the um2510 pdf (I used VL53L1X_CalibrateOffset and VL53L1X_CalibrateXtalk respectively).  After the calibration when I try to move the object away, the result distance is decreasing.  I dont get what the problem is but when I remove the glass ıt gives the correct result.

Thanks for your helps.

[John E KVAM · Accepted solution]

if the distance measure DECREASES when actual distance INCREASES, then it's a classic case of crosstalk.

With a large number of zero-distance "bad' photons averaged with the ones that did what you want 'good photons' you will under-range. But as your target gets farther away there will be fewer 'good' photons and a fixed number of  'bad' ones, causing the number to go distance measure to decrease.

If you've done a good calibration, you will get a value for the number of 'bad' photons. You can simply increase that number and try again. Be sure you are using a current driver, there was a bug in this area a couple of years ago. 

please note you have to calibrate, extract the value, store it in your memory and re-write it back into the sensor at every boot. 

I'm guessing it's this last requirement that is messing you up.