I am developing for an STM32F4. I’m using STM32CubeMX and System Workbench for STM32. I’m using FreeRTOS. I would like to know how I should, and should not, be using the STM32F4 HAL Driver callbacks.
As an example, I’m using HAL_CAN_RxCpltCallback. Within this call back, I decode and validate the CAN frame, and then generate a number of different events (i.e. using xQueueSendFromISR). Or in some cases, I populate a CAN frame in response, and send it within the callback. Currently I have 300 lines of code in this specific callback.
Ideally, I would make the callback easier to read, by calling out to additional functions; i.e. if the CAN frame/message is a request for date, then call handleRequestForData(), and so on.
However, I can see that HAL_CAN_RxCpltCallback is called from HAL_CAN_IRQHandler. So I take it that HAL_CAN_RxCpltCallback is also an IRQ. And its my understanding that I should keep all IRQ’s short, and not to call out to other functions (due to stack size limitations).
So my question is, should I minimize the amount of code in my callbacks. And in this case, simply push the CAN frame into another queue for another task to handle it?