STM32WL55JCI6 to STM32WLE5C8U6 issue

[SBébi.1]

Hi,

I developed an application with the Nucleo card which embeds an STM32WL55JCI6 starting from the "Sigfox_PushButton" example.

The program uses 60 kB of flash and 8 kB of RAM and therefore works under the STM32WL55JCI6 which embeds 256 kB of flash and 64 kB of RAM.

I would like to pass the programme to a smaller and cheaper microcontroller, the STM32WLE5C8U6 (64kB flash, 20 kB RAM).

So I imported the project from the new target under CubeMX, I only had to reassign the used pins.

Unfortunately, the problem is that when I compile the program, I am no longer at 60 kB of flash but at 84 kB used and the program therefore does not pass on the microcontroller. When looking at the flash memory usage details, the STM32WLE5C8U6 seems to consume much more memory in each function.

I don't understand why the program which is exactly the same has a different size from one target to another ? Also, does this mean that the STM32WLE5C8U6 is unusable with Sigfox ?

I'm confused, thanks for your help,

Steven

[RomainR.]

Hello @SBébi.1 (Community Member)

Have you done a comparison of the .map files that are produced by the linker?

By doing this, you should be able to find the cause of the excess flash memory usage!

Are you really sure that both projects are exactly the same? Is the STM32WL55JCI6 one optimized by the compiler?

Best regards,

Romain,

[SBébi.1]

Hi,

The projects didn't use the same compilation optimization, the code is less than 60 KB now everything is good!

Thank you,

Steven

[RomainR.]

Thank you for the feedback.

BR

Romain,

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