How to customize HAL using a general-purpose timer as main source of time base, instead of Systick.
In this example the used timer is TIM3.
Time base duration is kept unchanged: 1ms since PPP_TIMEOUT_VALUEs are defined and handled in milliseconds basis.
The example brings, in user file, a new implementation of the following HAL weak functions:
- HAL_InitTick()
- HAL_SuspendTick()
- HAL_ResumeTick()
This implementation will overwrite native implementation from stm32c0xx_hal.c and so user functions will be invoked instead when called.
The following time base functions are kept as implemented natively:
- HAL_IncTick()
- HAL_Delay()
- HAL_IncTick()
When user pushes the User push-button, the Tick increment is suspended if it is already enabled, else it will be resumed. In an infinite loop, LED4 toggles spaced out over 1s delay, except when tick increment is suspended.
Care must be taken when using HAL_Delay(), this function provides accurate delay (in milliseconds) based on variable incremented in TIM3 ISR. This implies that if HAL_Delay() is called from a peripheral ISR process, then the TIM3 interrupt must have higher priority (numerically lower) than the peripheral interrupt. Otherwise the caller ISR process will be blocked. To change the TIM3 interrupt priority you have to use HAL_NVIC_SetPriority() function.
The application need to ensure that the TIM3 time base is always set to 1 millisecond to have correct HAL operation.
System, TIM, Time base, HAL
This example runs on STM32C031C6Tx devices
This example has been tested with STMicroelectronics NUCLEO-C031C6 board and can be easily tailored to any other supported device and development board.
In order to make the program work, you must do the following :