Use case: COMP comparing by interruption

Description of usage

Operation

HAL1

HAL2

Start comparing

Activate Comparator analog features using HAL_COMP_Start_IT().

Activate Comparator analog features using HAL_COMP_Start_IT().

Comparator output trigger callback

Register the callback using HAL_COMP_RegisterCallback(), or implement HAL_COMP_TriggerCallback().

Register the callback using HAL_COMP_RegisterOutputTriggerCallback(), or implement HAL_COMP_OutputTriggerCallback().

Retrieve comparing result

Retrieve comparing results using HAL_COMP_GetOutputLevel().

Retrieve comparing results using HAL_COMP_GetOutputLevel().

Loop for multiple iterations

Possible multiple iterations if the comparator output has changed since the last read.

Possible multiple iterations if the comparator output has changed since the last read.

Stop comparing

Stop Comparator analog features using HAL_COMP_Stop_IT().

Stop Comparator analog features using HAL_COMP_Stop_IT().

Sequence diagram

@startuml title: COMP basic operation using programming model: interruption participant "User Application\n(thread mode)" as appli participant "User Application\n(handler mode)" as appli_IRQ participant "<font color=green><b>HAL COMP</b></font>" as COMP participant "HAL EXTI" as EXTI participant "System HW interruption" as interruption group#Bisque #Linen COMP operation appli->COMP : HAL_COMP_Start_IT() COMP->COMP : Enable selected interruptions\nActivate comparator analog features COMP->appli loop#lightgrey Possible multiple iterations interruption <[#red]-x? : <font color=red><b>COMP IRQ event interruption -> appli_IRQ : COMPx_IRQHandler() activate appli_IRQ #DarkSalmon appli_IRQ -> COMP : HAL_COMP_IRQHandler() COMP -> EXTI : Manage EXTI line flag COMP <- EXTI COMP -> appli_IRQ: <font color=blue><b> HAL_COMP_TriggerCallback() appli_IRQ->COMP : HAL_COMP_GetOutputLevel() COMP --> appli_IRQ: Logical level high/low appli_IRQ -> interruption : (return from ISR) deactivate appli_IRQ end appli->COMP : HAL_COMP_Stop_IT() return end @enduml

Code snippet

HAL1

HAL2 

int main(void)
{
  /*initialize and configure your comparing input*/

  /* Start the COMP  */
  HAL_COMP_Start_IT(&comp1);

  while(HAL_COMP_GetOutputLevel(hcomp) != COMP_OUTPUT_LEVEL_HIGH)
  {

    /* generate voltage on comparator inputs */

    /* add a Wait time for voltage stabilization*/

  }
  /* Stop the COMP  */
  HAL_COMP_Stop_IT(&comp1);
}

void HAL_COMP_TriggerCallback(COMP_HandleTypeDef *hcomp)
{
  if (hcomp->Instance == COMP1)
  {
    /* Handle the comparator event here */
    if (HAL_COMP_GetOutputLevel(hcomp) == COMP_OUTPUT_LEVEL_HIGH)
    {
      /* Comparator output is high */
    }
    else
    {
      /* Comparator output is low */
    }
  }
}

int main(void)
{
  /*initialize and configure your comparing input*/

  /* Start the COMP  */
  HAL_COMP_Start_IT(&comp1);

  while(HAL_COMP_GetOutputLevel(hcomp) != COMP_OUTPUT_LEVEL_HIGH)
  {

    /* generate voltage on comparator inputs */

    /* add a Wait time for voltage stabilization*/

  }
  /* Stop the COMP  */
  HAL_COMP_Stop_IT(&comp1);
}

void HAL_COMP_OutputTriggerCallback(COMP_HandleTypeDef *hcomp)
{
   /* Handle the comparator event here */
   if (HAL_COMP_GetOutputLevel(hcomp) == HAL_COMP_OUTPUT_LEVEL_HIGH)
   {
     /* Comparator output is high */
   }
   else
   {
     /* Comparator output is low */
   }
}

Key changes

  1. No major changes between HAL1 and HAL2. The only change is the renaming of the trigger callback.