VL53L0X X-NUCLEO-53L0A1 Cover Glass

[tomtom9197]

Posted on September 02, 2016 at 18:04

We are developing a product using the VL53L0X IR Time-Of-Flight sensor. The sensor must be inside a plastic case looking through a IR transmissible window material. To test such an arrangement the X-NUCLEO-53L0A1 comes with airgap spacers and cover glass materials. I would like to know what this cover glass material is, can you give a manufacturer name, article/product name or something?

#vl53l0x-x-nucleo-53l0a1

[harald]

Posted on November 07, 2016 at 14:31

Hy Sciro,

you never heard back from ST about your question, right? Apparently, this forum is not well maintained from them. Anyway.

I do not know, what kind of glass they use on the X-NUCLEO. I built a couple of devices that use a ''Acrylglas/Plexiglas® XT klar, 1.5mm'' I do not know the exact definition of the material, this is the name of the product I bought from my distributor.

I got if from ebay quite cheap:

http://www.ebay.de/itm/191787850626

I made some measurements with the glass. I find out, that the sensor surface must really be pressed to the glass tightly. As soon as I have a small gap or there is a tiny tilt between sensor surface and glass there is higher noise, less signal and an absolute error. Also the black-white drift and the ambient light influence increase. So what I do is mount the sensor as good as possible to the glass and then  glue it with silicone (I use the satelite board).

Maybe that helps. Regards

Harald

From: sciro

Posted: Friday, September 02, 2016 6:04 PMSubject: VL53L0X X-NUCLEO-53L0A1 Cover Glass

We are developing a product using the VL53L0X IR Time-Of-Flight sensor. The sensor must be inside a plastic case looking through a IR transmissible window material. To test such an arrangement the X-NUCLEO-53L0A1 comes with airgap spacers and cover glass materials. I would like to know what this cover glass material is, can you give a manufacturer name, article/product name or something?

[John E KVAM]

Posted on March 30, 2017 at 19:06

I'm fairly sure ST doesn't recommend glass because there are way too many choices and they can't test them fully.

The following chart shows some choices. PMMA is standard acrylic. It's cheap and available. But it scratches and generally one can see through it, so it might not be good for your application. Unfortunately there is no thickness measurement. I'm pretty sure thinner is better. One issue I have found with the ST 'glass' is that it is pretty fragile.

(Kcps - KiloCountPerSecond)

WindowPMMAPMMA +SAPPHIREGlass+PCPET

 (Embedded)IR coating IR Coating  

Transmission94%87-90%94%87-88%85%<80%

(840-960nm)

X-talk (VL53L0)<0.4Kcps0.4-0.8Kcps<0.4Kcps0.4-0.8Kcps0.5-1.0Kcps>0.8kcps

X-talk (VL6180x)<0.2Mcps0.5McpsNot tested0.25-0.5Kcps0.5Mcps>0.6Mcps

PerformanceBESTRisk of poor quality controlVery goodGOOD but risk of poor quality controlOk-ish. Not for Long RangeNot for long range

[John E KVAM]

Posted on April 06, 2017 at 19:58

Just found an ST application note - number AN 4907

http://www.st.com/content/ccc/resource/technical/document/application_note/group0/9d/93/be/33/13/be/46/19/DM00326504/files/DM00326504.pdf/jcr:content/translations/en.DM00326504.pdf

This describes what a good coverglass is. But it also gives a reference where you can buy the glass. Doesn't give a price though.

Might be worth a look.