Understanding VL53L5CX Range statuses

[VBhat.1]

If I point my VL53L5CX unit at the ceiling which I have measured to be 2.13m above my device, I get some readings that are status 5 of around 2100 mm and some readings that are status 255 of around 2100mm. Why is this the case? Because 2.1m is within the 4m rated distance (I have no coverglass as well), shouldn't every zone of my sensor be getting a proper reading?

And also what does it mean for the reading to be status 255 but the distance is correct? Can I trust these status 255 numbers?

[John E KVAM · Accepted solution]

Status 255 means you didn't get enough photons to get a good signal above the ambient background noise.

All the other numbers (except Ambient) for this collect are invalid. (They are left over from the prior collect.)

We claim you can get up to 3+ meters, but we claim that in ideal conditions.

I'm going to guess that you have;

• some sunlight causing a high ambient
• or perhaps an incandesent light source generating ambient light
• or particularly dull (non-refective) ceiling

I get a pretty good distance on a wood panel slanted ceiling - but with the sun streaming in the room through large windows, I cannot range that far.

Try it with the lights off and no sunlight coming into the room.

That will give you the max for that ceiling.

Then you have to account for real-life conditions.

• john