VL53L5CX exposure time (pulse counts) for one frame.

[Jsc]

Hi,

I want to know the exposure time of VL53L5CX per frame.
I also want to know that it is possible to configure the exposure time?

Best,
Jsc.

[John E KVAM]

Because the ST Imaging group also makes cameras, let's call what the VL53 sensors do, Integration time. This is the time the sensor spends getting you the answer. So if you want 15 frames and are running in continous mode, the integration time is 1 second / 15 or 66.6ms. 

But if you switch to automomous mode, you get to pick the integration time and the inter-measurement period. 

One could use a 5ms integration time, and an inter-measurement period 1000ms. So the sensor is alive but not doing much for 995ms. 

Integration time costs power, but you get accuracy. More integration time used => more accuracy and power consumed. 

So decide your power budget, your tolerance for latency, and how much accuracy you need. Then sent your integration time and inter-measurement time. 

Or, if running in continuous mode, just sent the number of ranges per second. 

[Jsc]

Thanks for your reply.

I still have some questions. In the continous mode, I want to know the actually default integration time (not 1/15 s), because the sensor not always work during 1/15s.

Besides, the automomous mode only provide one frame data?
Or automomous mode is a custom continous mode?

Looking forward to your reply.

[Jsc]

Thanks for your reply.

I still have some questions. In the continous mode, I want to know the actually default integration time (not 1/15 s), because the sensor not always work during 1/15s.

Besides, the automomous mode only provide one frame data?
Or automomous mode is a custom continous mode?

Looking forward to your reply.

[John E KVAM · Accepted solution]

The sensor will range until you tell it to stop. But in Continuous mode, there is no empty time between ranges. In autonomous mode you get to select the time between successive start times.

If you tell the sensor the integration time is 10ms and the inter-measurement period is 100ms, you will range for 10ms, the sensor will rest for 95ms and then start again. (There is a couple of milliseconds of overhead, so the laser might be on for only 8ms out of the ten.)

I suppose there might be a default integration time, but I'm not sure what it is. All the code I ever run sets the timing and I think you should do that too. It's just safer. 

We wrote the code to assist a cellphone camera. And cameras really default to 30 frames per second. So, if there is a default, it's probably set up to running continuously at 15 frames per second. 

- john

[Jsc]

Thanks John.