VL53L1X Set ROI Center value using Ultra lite drivers

[AFull.1]

Hi,

I am wondering if someone can help me. I am working with the X-Nucleo-53L1A1 board and I am using the STSW-IMG010 people counting example. In this example the 2 8*16 zones get defined using a center value of 167 and 231 repectively (using the SetROICenter function in the Ultra Lite Driver). I am wondering where do these values come from? I know it is a 16*16 SPAD grid meaning that there are 256 SPAD in total, so I thought that it would be just referring the grid number starting from 0 going left to right all the way up to 255.

But when I look at these values (167 and 231) this doesn't make sense for 8*16 zones.

The reason why I am asking is I would like know how to change the orientation of the zones, so for this example you move from left to right to moves zone. In my case I would like the zone to be defined by moving my from top to bottom of the sensor. The diagram attached shows what I mean.

Thank you for your help,

Ashley Fuller

[kwc]

In case you're still looking for an answer, and for anyone else with the same question, it looks like there's a table of the SPAD numbering in UM2555 (section 4.1, SPAD locations): https://www.st.com/resource/en/user_manual/dm00600212-vl53l1x-ultra-lite-driver-multiple-zone-implementation-stmicroelectronics.pdf