VL53L1X or other people flow sensor- minimum power and sensor choice

[Tcodd.1]

I'm researching the usefulness of the VL53L1X for people flow detection in/out of a room. I know example given but I'm left with two questions:

A) Which of the SM ToF sensors in VL53 series might provide same capability as example?

B) Without experience and experimentation I'm unclear how low the power consumption would be for a door sensor based on VL53L1, for example, so I can determine battery life?

Also, what mode, settings, and sampling approach etc would ideally provide an interrupt driven continuous door sensing capability with minimum power consumption?

Thanks for your consideration.

[John E KVAM]

power is always a problem.

the sensor uses 20mA while ranging, and a reasonable range takes 20ms.

So to range once 3 times per second you need 20mA *0.020seconds * 3 samples/sec = 1.2mA

So if you just wanted to detect slow moving things like a hand under a faucet 3 times per second is fine.

But to measure people through a door, you need to range enough to determine direction. And to do that you must range continuously.

I used the VL53L1X and created 2 zones. An inner and an outer. Then I ping-ponged between them using not only the range information, but the signal strength information and I was able to determine if the inner was hit before the outer indicating an exit or the other way around.

But to do it I had to range continuously. And that uses 20mA. So a battery is not going to work very well.

Sorry about that.

• john

[Tcodd.1]

john, I appreciate that you read my post and replied. In light of this information I will look at what my options are. Thanks