VL6180 and 3143 Infrared Transmitting Acrylic

[TMang.1]

Sensor: VL6180

Material: 3143 Infrared Transmitting Acrylic 3mm thick.

Using API?: No. My own code using the data registers.

Problem: Need an object in path only if using cover

I currently have the VL6180 setup and working well in open air from a previous project. Running continuous range only. Using a PIC processor.

A client gave me this material so I could implement a no touch solution. The sensor is able to go through the material but only if I am basically right on top of the material. Even then, it is finicky about position. When I have the sensor in the right position, I am having an issue where, if I don't have an object within about 30 cm of the sensor, the measurement come back incorrect(short lengths). If I have an object within this 30cm and lined up correctly, then it measures well enough.

I do not have this issue of needing an object if in open air.

What could be causing this?

[John E KVAM]

Crosstalk. Review the information in the datasheet and usermanual on Crosstalk. Also view the video:

VL6180X Dirty Cover Glass: https://youtu.be/7INefyjvvdI

It explains the problem and gives a hardware solution.

But you can possibly just calibrate out the crosstalk.

Good luck,

• john

[TMang.1]

So far I have been unable to calibrate out the crosstalk in software.

For the hardware solution in the video, is this something that ST sells? Or would we have to make one ourselves?

[John E KVAM]

Both the coverglasses ST includes in the evaluation kit are made by www.hornix.com.tw. Go to their site, click on products and pull all the way to the bottom. You will see a list of all the oval glasses they sell off the shelf. But they are an optical company that does plastic molding. They can build you something custom if you ask them (and pay of course.)

there is a contact on that page somewhere.

• john