Issues with FreeRTOS queue and changing "Queue Size" and "msg_size"

[Mike xx]

There are times where I would like a message queue of a single depth. In some similar OSes this is also how semaphores are created. I have hit a near brick wall in STM32CubeMX failing to create a queue with just one element.

In this case for the STM32F4 library, I get the following call where I set a "Queue Size" 1 in:

Middleware -> FreeROTS -> Tasks and Queues -> Queues -> Queue Size.

This creates a function:

I2CWriteQHandle = osMessageQueueNew (2, sizeof(i2c_data_type), &I2CWriteQ_attributes);

Note the "msg_count" argument is 2, despite all the I2CWriteQ_attributes being consistent with those being set in ST32CubeMX. If the queue is increased to say 16, msg_count remains at 2. Other queues with a osMessageQueueNew "msg_count" set at 16, remain at 16.

If I manually correct the "msg_count" argument, the new value is retained when (re)generating the code.

I presume this behaviour of unlinking "Queue Size" "msg_count" is unintened and not sure when this issue started. BTW I am using v6.7.1 and have applied the patch associated with this version.

[Semer CHERNI]

Hello @Community member​ 

Frist let me thank you for posting.

I have an issue reproducing the described behavior.

I am using the following setup:

• STM32CubeMx 6.7 with the patch applied
• STM32CubeIDE 1.11.2
• Windows 10
• STM32F439 MCU

Down bellow screenshots from the CubeMx setting and the generated code:

Could you provide a project where the issue is reproduced or at least an *.ioc file.

Kind regards,

Semer.

[Mike xx · Accepted solution]

I apologise for not replying earlier.

Soon after getting this issue I upgraded the CubeMX applications.

What I can say is that I can't reproduce the problem with STM32CubeMX v6.8.0

I've change the queue size and the corresponding numbers ("Queue Size" "msg_count") in freertos.c change as one might expect and the project compiles fine.