Posted on September 05, 2014 at 05:28I'm trying to set up interrupt on falling/raising edge on output PWM line. This line drives LEDs (through TI LED driver chip). The reason why I need this is that the TI chip would report issues on a different pin but this pin is synchronized with PWM line - one comms bit per PWM signal.
I've tried to configure update interrupt but the handler never gets triggered. Any ideas why?
Here's my code
#define LED_GPIO_PORT GPIOA
#define LED_GPIO_RCC RCC_APB2Periph_GPIOA
#define LED_GPIO_PWM_PIN GPIO_Pin_11
#define PWM_FREQUENCY_Hz 3000
#define PWM_MAX_DUTY_CYCLE 40 // 40%
#define LED_TIMER TIM1
#define LED_TIMER_RCC RCC_APB2Periph_TIM1
void LEDInit( void )
{
....
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
// turn on clocks
RCC_APB2PeriphClockCmd( LED_GPIO_RCC | LED_TIMER_RCC, ENABLE );
NVIC_InitStructure.NVIC_IRQChannel = TIM1_UP_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 3;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* TIM IT enable */
TIM_ITConfig( LED_TIMER, TIM_IT_Update, ENABLE );
TIM_Cmd( LED_TIMER, ENABLE );
GPIO_InitStructure.GPIO_Pin = LED_GPIO_PWM_PIN;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init( LED_GPIO_PORT2, &GPIO_InitStructure );
TIM_TimeBaseStructure.TIM_Period = (SystemCoreClock/2) / PWM_FREQUENCY_Hz - 1;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned1;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit( LED_TIMER, &TIM_TimeBaseStructure );
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
TIM_OCInitStructure.TIM_Pulse = period - dutyLength;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;
TIM_OC4Init( TIM1, &TIM_OCInitStructure );
TIM_OC4PreloadConfig( LED_TIMER, TIM_OCPreload_Enable );
TIM_CtrlPWMOutputs( LED_TIMER, ENABLE );
}
void TIM1_UP_IRQHandler(void)
{
if (TIM_GetITStatus( LED_TIMER, TIM_IT_Update ) != RESET)
{
// do something here
TIM_ClearITPendingBit( LED_TIMER, TIM_IT_Update );
}
}
