Problem with the new VL53L1X

[MarceloSouza]

In my product I use the VL53L1X sensor for more than 2 years. But the last 50 sensors I bought had a problem. The measurement is too incorrect and the peak_signal_count_rate_MCPS and ambient_count_rate_MCPS parameters are too low. I purchased sensors from two different vendors and both had the same problem. 

The image below shows my test device. The first two lines of the display show data from the new sensor with a problem. And the last two lines show data from a sensor that is working correctly, used as a reference.

 

My doubts are:

Have there been any firmware updates recently?
As I import this component, could the customs X-ray have damaged the sensor?
Is there anything else I can check to try to resolve the issue?

[Anne BIGOT]

Hello,
For such product, the FW is embedded in a ROM. No update has been done recently.
Did you change anything in your setup ? Cover- glass for example ?
Did you try to use the same setup (cover-glass included) by changing just the sensor ?

It seems that you are not using a ST official board meaning board sent by ST (VL53L1X-SATEL). Can you confirm ?

Regards

Anne

[John E KVAM · Accepted solution]

I'd start by removing that coverglass and seeing if the probem magically goes away. My guess is that it will.

I had a cellphone vendor who built his first 100 units - and left the protective bit of tape on the part. 

The reason for the signal fail is that not enough photons are being returned to get an answer. Therefore, my guess is that the cover is somehow blocking the light. 

Removing the coverglass should fix the issue. Then you have to figure out what the glass is doing something wrong. I suppose it could be dirty - or scratched.

I had a problem like this before. It was someone cleaning the optical element with a Brillo pad. Massive scrathes killed the system.