Posted on August 07, 2015 at 09:58Hello,
I'm trying to set my timer3 on ch1 to make an interrupt with some frequency (100Hz). The idea is to switch it on and off by using a USER button situated on my stm32f3 board. I programmed it but it sometimes count way too fast than it's configured, I mean I placed a variable counter which is increasing after every interrupt from TIM3. Sometimes when I switch this timer for 1 sec it counts 100 impulses but sometimes 500 or even 1000. Can anyone tell me where am I making mistakes?
TIM3CH1 configuration:
void MX_TIM3_Init(void)
{
TIM_MasterConfigTypeDef sMasterConfig;
TIM_OC_InitTypeDef sConfigOC;
htim3.Instance = TIM3;
htim3.Init.Prescaler = 2;
htim3.Init.CounterMode = TIM_COUNTERMODE_DOWN;
htim3.Init.Period = 65535;
htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
HAL_TIM_OC_Init(&htim3);
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig);
sConfigOC.OCMode = TIM_OCMODE_TIMING;
sConfigOC.Pulse = 0;
sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
HAL_TIM_OC_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_1);
}
and a part where I turn the timer on and off:
int tim_trigger=0;
while(1){
button1=HAL_GPIO_ReadPin(GPIOA, GPIO_PIN_0);
if(button1==GPIO_PIN_SET){
if(tim_trigger==1) tim_trigger=0;
else tim_trigger=1;
}
if(tim_trigger==1){
HAL_TIM_OC_Start_IT(&htim3, TIM_CHANNEL_1); // start timer
}
else{
HAL_TIM_OC_Stop_IT(&htim3, TIM_CHANNEL_1); // stop timer
}
.
.
.
}
and of course timer interrupt function:
void TIM3_IRQHandler(void)
{
HAL_TIM_IRQHandler(&htim3);
licznik=licznik+1;
}
