Is it possible to use the ULTRA LITE DRIVER (SWST-IMG009) for VL53L1X to manage and control the VL53L1 ToF Sensor?

[VNava]

Hi! My name is Vincenzo.

Taking a look at the two sensors, I started to believe that they are similar in terms of Architecture, more precisely it seems to me that the VL53L1 has expanded the characteristics of the VL53L1X at the expense of a slightly lower maximum ranging distance. As I feel that the Ultra Lite version of the API for VL53L1X is very useful, I would like to know if I can use it to manage the VL53L1.

Thanks in advance for your support

Vincenzo

[John E KVAM]

The VL53L1CB (the formal name of the VL53L1) is a super-set of the VL53L1X.

The VL53L1X will run the Ultrlite driver STSW-IMG009 and the full version of that driver - STSW-IMG007

The VL53L1CB will run ALL the code. The two above AND the STSW-IMG019 software which gives you the Historgram feature.

The CB version is a touch more expensive, so if you don't need the Histogram feature and larger software that goes with it, use the VL53L1X.

In a new design one might consider going with the CB version and trying all 3 sets of code in your prototype.

Then, if the easier code works out, go into production with the VL53L1X.

• john

[VNava]

Hi John!

Thank you very much for your attention and for this useful information.

Given this fact, if it is possible, I would like to ask you some questions.

I would like to know if there is a difference in terms of performance between VL53L1X and VL53L1CB. In fact, I recently saw an Application Note (AN5573) which updates the performance of the CB. Does this update affect only the CB or other ToFs too? Also I would be curious to know if, in regards to the sunlight immunity, the two ToF behave the same way or if CB has better immunity to sunlight.

Considering the case in which there are differences between the two ToF in terms of perfromance (like immunity or maximum ranging distance), these performance don't depend on the type of code you use, right?

That is, if by hypothesis I choose ToF VL53L1CB, Does its performance remain unchanged both using the ultralite driver for L1X and using the STSW-IMG019 driver?

Thanks again,

Vincenzo

[MT.10]

I am wondering if there is an answer to this last question: "That is, if by hypothesis I choose ToF VL53L1CB, Does its performance remain unchanged both using the ultralite driver for L1X and using the STSW-IMG019 driver?".

I am using the VL53L1CB with the VL53l1X driver and I'm just trying to get readings up to the maximum 8m range. However, it is not giving me readings greater than 4m. I don't need to use the histogram feature. How can I get the maximum ranging distance out of the VL53L1CB? I would like to use the VL53L1X driver if possible since it runs on an Arduino, whereas the L1CB driver is too large to run on even an Arduino Mega.

[John E KVAM]

The VL53L1X uses what we call 'standard ranging', it uses statistics to get the answer and that answer is completely embedded inside the chip. It's max distance is 4m.

The VL53L1CB uses Histograms. Each bin of the histogram is the number of photons collected in that clock cycle. The histograms are then sent back to the host, and the host extracts the answers.

Physically the device is limited to 4M. But we have all the data in the host so we can do some additional processing. We can 'unwind' the wrap-around check and look for distances up to 8 meters. This process assumes you are looking at a very refective target - such as a projection screen. (It well may be that a projection screen is the only thing large enough and reflective enough to actually go 8M. But that's the use case we were solving.)

It's the host processing that gives you the far distances. And it's why the host processing is larger than the ULD.

You say that you don't need the histograms, but it's only the histogram proessing that will give you those far distances. Histograms and a large, reflective target that is.

[MT.10]

Hi John,

Thank you very much for explaining the significance of the histogram feature in reaching the maximum distance. Therefore, if I were to implement the VL53L1CB API, I should be able to read measurements up to 8m at 30 Hz (33 ms timing budget) as specified on Table 1 of the Ranging Mode Performances document for the VL53L1? Also is it a typo that it says that it will read the maximum distance under Medium distance mode? Because in other documentation it says that the Long distance mode is necessary to obtain the maximum range.