sths34pf80 + lens

[apallo]

Hi!

We are working on product that needs to count people on the range of 3-4 meters. We designed dev.board for sths34pf80 and tetsted it with UNICO-GUI. The max range that we are getting is around two meters and therefore it looks that we need to use additional lens to extend the range.  I found one of your documentation " New industrial sensors:anomaly detection and presence" where you have descibed it working together with a lens. So we bought the same lens IML-0687 and tested it, but we are not reproduce the same results. With a lens the range is even less than without it. I played with different settings, but no success. 

There also should be document  AN5983, that describes the work with lens, but looks like its not created yet. 

Have you got any suggestions for us, to get it work?

[Federica Bossi · Accepted solution]

Hi @apallo ,

Welcome to ST Community!

You need to follow the datasheet of the lens, that I attached, for the right placement on the STHS34PF80.

Pay attention to the fact that the focus of the lens must to be centered to the sensitive area of the sensor.

If this helps you, please mark my answer as "Best Answer" by clicking on the "Accept as Solution" button, this can be helpful for Community users to find this solution faster.

[jmeck]

According to AN5983 (Reference Lens of the STHS34PF80 in the final application), and my own testing, the Fresnel Factory TMOS63-10 lens is to be mounted with the Grooved Surface of the Fresnel Lens mounted away from the STHS34PF80 sensor.  However, the lens is mounted opposite in the little 3D printed holder that comes from the Fresnel Factory or with the ST STEVAL-MKI1231KA sensor evaluation board.  The lens holder has a recessed mounting lip, so the lens can not simply be remounted in the correct orientation.  As a workaround I 3D printed my own holder based upon the mounting dimensions in AN5983.

[jmeck]

@Federica Bossi  Can your team resolve the apparent conflicting lens mounting orientation specification between the Fresnel Factory documentation, AN5983 and the sample lens mount included in the ST STEVAL-MKI1231KA sensor evaluation board?

[Federica Bossi]

Hi @jmeck ,

We can confirm what is reported in the AN5983: the lens must be mounted with the grooved surface facing outward from the sensor.

If in your kit, the lens is not properly mounted, you just have to open the holder and flip it.

[jmeck]

@Federica Bossi  Thanks for confirming AN5983 on orientation of the Fresnel Lens.  Please note that the Fresnel Lens has a flange (as shown in the illustration in AN5983), which causes the lens to only fit one way in the ST STEVAL-MKI1231KA sensor evaluation board lens mount.  If I am not mistaken, it the kit mount is reverse from the mounting orientation described in AN5983?  The included mount has a recess for the flange on the wrong part.