VL53L1X Low Range issue

[spiralbrain]

We use the VL53L1X in one of our products and have been doing that for over 2+ years now. As this device is not easily solderable, we have been relying on the Chinese supply of breakout boards used in the hobby market. 

Just recently we are facing range issues with entire lots of this sensor based boards. All of them exhibit range issues where the Sensor is unable to detect beyond 30 to 40cm. I thought it could be a calibration or offset issue. I've tried getting offset values using the 17% Gray sheets as recommended. Any help in this regard will be appreciated. Thanks.

[John E KVAM]

I've seen this before. Someone forgot to take the protective liner off the sensor.

We put that bit of tape over the sensor to prevent debris from getting into the sensor. And unfortunately, it's almost transparent. 

You would not be the first. A cellphone vendor did this and had to take apart 100 phones. 

what is happening is that the liner is causing a huge number of photons to be reflected back into the sensor. With a million photons at zero-distance, all your numbers are low. 

Please check it carefully.

- john

[spiralbrain]

Hi John,

Thank you for a quick reply. I did check and the Kapton tape protection is not on, I've verified that. 

The difference I've noticed is that now the tape is removed by who ever is assembling the breakout boards. Many people must have faced this issue in the past. 

Thanks,

-raman