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FreeRTOS ported to the PSoC 4

Former Member

I've ported FreeRTOS to PSoC 4 - which really was extremely trivial. It's simply the Cortex M0 port with some configuration & glue from the PSoC 5 demo.

The attached demo app creates three tasks that toggle the red, green and blue LEDs on the PSoC 4 pioneer board at slightly different rates, resulting in a pleasing (if somewhat psychedelic) light show. Adapting this demo for your own purposes should be straightforward.

Note that because the PSoC Capsense component makes (undocumented) use of the systick timer, it's not currently possible to use FreeRTOS and the PSoC Capsense component together.

Attachments:
FreeRTOSDemo.zip
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  • in reply to Former Member

    Well, your code worked fine - I did not have to change a thing.

     

    I then added a CapSense component and a task to monitor it periodically. That caused PSoC Creator to complain that I was out of RAM. I just made a few changes to make it fit. The main cause of the problem was that Creator assumes you want it to pick your stack and heap size. FreeRTOS does that for you and so I had a large amount of RAM allocated that was never going to be used. In the FreeRTOSDemo.cydwr file I changed the stack size to about 80 bytes, which is plenty to run main() and kick off the RTOS. I set the heap size to 0 bytes because it is not used by FreeRTOS at all.

     

    That freed up a lot of room for the task stacks and FreeRTOS heap. I believe that FreeRTOS allocates task control blocks and stacks out on array of size configTOTAL_HEAP_SIZE (ucHeap). I have not had a chance to really dig into RAM usage memory with FreeRTOS though - I just wanted to play with your "port", ran into a problem and solved it. I hope to take a closer look in the new year.

     

    -- Mark.