cancel
Showing results for 
Search instead for 
Did you mean: 

Ways to reduce the impact of cover glass

Wwei
Associate

Hi,

I'm using the VL53L4CX and I  find  that using the xtalk calibration still doesn't completely remove the data from the cover glass. Is there any other way to remove the near distance data?

The VL53L0CX can adjust the threshold of a signal by a function, can the LV53L4CX do the same?

 

Thanks

 

1 ACCEPTED SOLUTION

Accepted Solutions
John E KVAM
ST Employee

The single zone sensors can be divided up into Histogram-based and standard ranging parts. 

L0, L1X, L4cd are all standard ranging parts.

L1CB, L3X and L4CX use histograms. 

On the histogram parts one can do a really good job of crosstalk calibration by simply pointing the sensor out into space. With no target, all the photons that come back are from crosstalk. And we can count them directly, and we can subtract the right number from each bin. (And with the histograms, there is no crosstalk past 80cm - which can be a big advantage. 

With the standard ranging one has to work out the crosstalk by knowing the distance to the target, and using both the range data and the signal strength to work out the crosstalk value. 

If you are having issues perhaps you can lower the crosstalk. 

Read the article:

https://community.st.com/t5/mems-and-sensors/time-of-flight-cover-glass/ta-p/49259

it might give you some ideas on how to lower the value. 

- john


In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question. It helps the next guy.

View solution in original post

1 REPLY 1
John E KVAM
ST Employee

The single zone sensors can be divided up into Histogram-based and standard ranging parts. 

L0, L1X, L4cd are all standard ranging parts.

L1CB, L3X and L4CX use histograms. 

On the histogram parts one can do a really good job of crosstalk calibration by simply pointing the sensor out into space. With no target, all the photons that come back are from crosstalk. And we can count them directly, and we can subtract the right number from each bin. (And with the histograms, there is no crosstalk past 80cm - which can be a big advantage. 

With the standard ranging one has to work out the crosstalk by knowing the distance to the target, and using both the range data and the signal strength to work out the crosstalk value. 

If you are having issues perhaps you can lower the crosstalk. 

Read the article:

https://community.st.com/t5/mems-and-sensors/time-of-flight-cover-glass/ta-p/49259

it might give you some ideas on how to lower the value. 

- john


In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question. It helps the next guy.