VL53L7CX et VL53L8CX

[Freedy]

I recently purchased a VL53L7CX and VL53L8CX, so I wanted to test the Motion Indicator functionality for each zone to show if the targets moved and how they moved via SPD of the software by STM except that there, when two people present themselves in front of the sensor, we only see one person
How to do it?

[John E KVAM]

SPD will track the first person into the FoV. This is because we were trying to sell it into the PC market and we assumed we were following the main user. And when 'he' left we assumed we could shut down the PC. We really did not build in a second user. 

But here is how you do it...

Run through all the zones looking for those zones that have more-or-less the same distance. That 'clump' of zones is probably one of your users. Now find the center of mass of that clump. Then look for another clump. That's your second user. 

The trick comes when you have to decide if it's a user or a chair. One can assume chairs don't move. But sometimes they do. And if they are tall chairs, they even have the right shape - more or less. 

Handle the corner cases and you are all set.

 -john

[Freedy]

Except that in the presentation video of VL53L7CX and VL53L8CX you illustrated multitarget detection which led me to buy it for a project even though this is not the case
Communicate what is real!

[OlivierL · Accepted solution]

I confirm that SPD is able to detect and monitor the X/Y/Z position of up to 4 different persons, provided those persons are far enough from each others to be identified/separated within the 8x8 depth map...

[OlivierL]

Let me complete my reply with more details...

To visualize the (X, Y, Z) position of each person in front of the sensor, you can use the SPD EVK GUI and use the Users Analysis widget as shown below...

If you prefer using your favorite Serial Com emulator like TeraTerm, you'll get this kind of outputs showing the same kind of information...

From a pure programmatic point of view, below is a pseudo-code giving the name of the fields of interest to get access to the Multi-Human outputs...

// Users outputs (including intruders)
SPD_Data.USR_Data.nb_of_users
SPD_Data.USR_Data.intruder_alert
for (i=0;i<4;i++){
  SPD_Data.USR_Data.user_properties[i].obj_prop.CoM_pos.x
  SPD_Data.USR_Data.user_properties[i].obj_prop.CoM_pos.y
  SPD_Data.USR_Data.user_properties[i].obj_prop.CoM_pos.z
  SPD_Data.USR_Data.user_properties[i].intruder
}

More details can be found in the SPD EVK GUI User Manual...

Hope this helps...