timer_stm.c

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#include "timer.h"
#include "stm32l4xx.h"
#include "main.h"
 
/************************** Module variables **********************************/
// Store the last timer value to calculate the elapsed time
static volatile TIMEVAL last_time_set = 0;//TIMEVAL_MAX;
static volatile TIMEVAL elapsed_time = 0;
 
void setTimer(TIMEVAL value){
    uint32_t timer = TIM2->CNT;
    elapsed_time += timer - last_time_set;
 
    last_time_set = 65535-value;
    TIM2->CNT = last_time_set;
 
    TIM2->CR1 |= 1; //Re-enable timer
}
 
void initTimer(void)
{
 
}
 
UNS8 isTimedOut( UNS32 *tRef, UNS32 tAlarm )
{
 
    if( (HAL_GetTick() - *tRef) > tAlarm )
    {
        return 1;
    }
 
    else
        return 0;
}
 
void resetTimeOut( UNS32 *tRef )
{
    *tRef = HAL_GetTick();
}
 
TIMEVAL getElapsedTime(void)
{
    TIMEVAL timer = TIM2->CNT;
 
    if (timer > last_time_set)                    // In case the timer value is higher than the last time.
      return (timer - last_time_set);             // Calculate the time difference
    else if (timer < last_time_set)
      return (last_time_set - timer);             // Calculate the time difference
    else
      return TIMEVAL_MAX;
}
 
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
    if (htim->Instance == TIM2) {
        last_time_set = 0;
        elapsed_time = 0;
        CLEAR_BIT(TIM2->SR, TIM_SR_UIF); //Clear pending interrupt
        TimeDispatch();
    }
}