2019-06-30 06:36 AM
Dear Members,
I want to count pulse from EXTI4, and
I tried to set 30 seconds for how many pulse ?
Please correct my setting :
void MX_TIM4_Init(void)
{
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
TIM_OC_InitTypeDef sConfigOC = {0};
htim4.Instance = TIM4;
htim4.Init.Prescaler = 0;
htim4.Init.CounterMode = TIM_COUNTERMODE_UP;
htim4.Init.Period = 10000;
htim4.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
if (HAL_TIM_Base_Init(&htim4) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim4, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_OC_Init(&htim4) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim4, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigOC.OCMode = TIM_OCMODE_TIMING;
sConfigOC.Pulse = 0;
sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
if (HAL_TIM_OC_ConfigChannel(&htim4, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
HAL_TIM_MspPostInit(&htim4);
}
void GPIO_EXTI4_Callback()
{
count++;
}
void Timer_4_Callback()
{
printf("TIMER4Callback\r\n");
seconds += 1;
if (seconds == 30)
{
minute = 1;
seconds = 0;
rpm=count;
rps=(uint8_t)rpm/30;
count=0;
}
}
on main()
current_rps=rps;
if (minute==1)
{
printf("BPS = %u",current_rps);
minute=0;
}
my clock is 2.097MHz , TIMER4 STM32L152RE
Any clues ?
thanks
2019-06-30 08:30 AM
People normally use the SysTick at 1ms, and count off 1000 periods.
You could likely use a 16-bit timer with appropriate prescaler/period to count 2097000 cycles.
2019-07-01 12:07 AM
any examples on how to use that method ?
pseudo code ?
Systick = 1000ms,
check how many counts ?
thanks