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VL53L0X: I would like to use the RANGE IGNORE THRESHOLD but don't know what value to start with. The documentation states N x Xtalk Mcps/spad, where N = 1.5 by default. However I do not use Xtalk. Any idea on how to obtain a useful starting value?

LICH
Associate
 
1 REPLY 1
John E KVAM
ST Employee

​From the user manual:

• Range Ignore Threshold

VL53L0X_CHECKENABLE_RANGE_IGNORE_THRESHOLD

Signal rate minimum threshold. Measurements with signal rates below this value are

ignored. This ensures that false measurements are not made due to reflection from the

housing.

And:

Range Ignore Threshold, Default limit state - normally disabled,

Default limit value = N x Xtalk Mcps/spad

where N = 1.5 by default

So how to set it...

The first thing you need is the crosstalk value. Crosstalk is the signal returned by the coverglass. There is a function to measure it. And the value returned is in the proper units (Xtalk in Mcps/spad)

If you don't use Xtalk, then you have a problem.

Can you measure the Xtalk and use that value, even it you never set the crosstalk again?

Generally one sets the Range Ignore to 1.5 times the crosstalk. Otherwise one might identify the coverglass as a target - which would be just wrong.

If you want to be very sensitive to targets farther away, you might want to try a lower multiplier.

If you don't use Xtalk, then try a low number - I'd say .4 kilo counts would be a first good guess.


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