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Relationship between distance and ambient in vl53l8cx TOF sensor

JunSheng
Associate

Does the ambient value affect the distance measurements in the VL53L8CX, or are both parameters independent of each other?

1 ACCEPTED SOLUTION

Accepted Solutions
John E KVAM
ST Employee

Just prior to turning on the VCSEL (laser) light, we take a measure of the Ambient. Then we subtract the ambient leaving us with Signal over ambient. Then we determine where the target is from that signal. 

So in theory the Ambient has no effect on the measurement. 

But in really bright light, the ambient is so strong that it saturates all of our SPADs (photon detectors). When this happens, we have no ability to 'see' the signal. 

In summary, the ambient has no effect on the measurement but it does affect how far the sensor can range. 

- john


If this or any post solves your issue, please mark them as 'Accept as Solution' It really helps. And if you notice anything wrong do not hesitate to 'Report Inappropriate Content'. Someone will review it.

View solution in original post

1 REPLY 1
John E KVAM
ST Employee

Just prior to turning on the VCSEL (laser) light, we take a measure of the Ambient. Then we subtract the ambient leaving us with Signal over ambient. Then we determine where the target is from that signal. 

So in theory the Ambient has no effect on the measurement. 

But in really bright light, the ambient is so strong that it saturates all of our SPADs (photon detectors). When this happens, we have no ability to 'see' the signal. 

In summary, the ambient has no effect on the measurement but it does affect how far the sensor can range. 

- john


If this or any post solves your issue, please mark them as 'Accept as Solution' It really helps. And if you notice anything wrong do not hesitate to 'Report Inappropriate Content'. Someone will review it.