VL53L9 software package for low resource microcontroler ?

[DrPiWork]

Hi,

 

I’m trying to use a VL53L9 with a microcontroller which have 128kB of RAM. For this I use the STM32CubeExpansion_53L9A1_V1.0.0 package. 

The problem is the streaming library delivered within the package is not made for low RAM usage. It’s stack usage is high. Too high for the microcontroller I use.

Is there VL53L9 software implementation available for low RAM usage ?

 

Regards,

Nicolas

[MeganeG]

Hello ​@DrPiWork,

We do not have a specific software package for low-resource microcontrollers. However, some functions can be disabled, such as the TNR and sharpening algorithms, and the resolution can be reduced by using binning.

Thanks, Megane

[DrPiWork]

Hello ​@MeganeG ,

 

Thanks for your answer.

Can I completely avoid the usage of the streaming library (it is not clear to me what it is used for) ?

 

Best regards,
Nicolas

[MeganeG]

Hello ​@DrPiWork,

Which library/file are you mentioning exactly?

Thank you, Megane

[nico23]

To reduce FLASH usage you can also make sure to have float operations instead of double precision operations.

For instance, in the API of the VL53L1X (which is a similar sensor of the one you’re using), some operations were using double precisions numbers. Turning them to floating one I’ve not noticed a degradation of the operation of those specific APIs but a huge increase of flash savings (if, of course, you’re not using double precision operations anywhere else on the code)

[DrPiWork]

Hi ​@nico23 ,

 

Thanks for your answer.

My problem is not with FLASH but with RAM.

The streaming library allocates large arrays on the stack.
For example, the compute_norm_maps() function (called at init) uses 146736 bytes of stack by itself (Static Stack Analyzer output) . To this, you have to add the stack usage of other functions.
The STM32 I use has 128kB of RAM. This is less than the stack usage of the compute_norm_maps() function.

For a 54x42 pixels sensor, this seems largely oversized.

Regards,
Nicolas