I get same Capture Value when using input capture mode on the same timer

[EmbeddedPepe]

Hi,

I basically have two PWM signals going into two pin that are set to be TIM4_CH1 and TIM4_CH2.

I setup both channels in slave mode and enabled the input capture mode on Rising mode.

When I enable only channel 1 and the code below get executed I retrieve the correct CCR1 values and consecutively I calculate the correct duty cycle.

Problem: When I enable both channels I get the same CCR1 and CCR2 value, all the time, so the duty cycle is always 100%

Input capture mode on "Both_Edges" mode work strangely because instead of getting the rising and falling edge captures consecutively I get them randomly: sometimes I just get the falling, sometimes only the rising and most of the time random pattern ( ex. rising, rising, falling, rising). So I opted to switch edge detection mode everytime I capture the value.

void TIM4_IRQ_PWM(void)
{
	if (TIM_GetITStatus(TIM4, TIM_IT_CC1) != RESET) {
			tmyPWMInput *pPWM4_1 = &myCTRL.myHW.myPortDCfg.myPWM4_1; //PIN12
			                  // Clear TIM8 Capture Compare1 interrupt pending bit
			TIM_ClearITPendingBit(TIM4, TIM_IT_CC1);

			if ( is_rising_ch1 )
			{
				pPWM4_1->FullPeriod = TIM_GetCapture1(TIM4);

				TIM_CH1_ICInitStructure.TIM_Channel 		= TIM_Channel_1;
				TIM_CH1_ICInitStructure.TIM_ICPolarity 		= TIM_ICPolarity_Falling;
				TIM_CH1_ICInitStructure.TIM_ICSelection 	= TIM_ICSelection_DirectTI;
				TIM_CH1_ICInitStructure.TIM_ICPrescaler 	= TIM_ICPSC_DIV1;
				TIM_CH1_ICInitStructure.TIM_ICFilter 		= 0x0;
				TIM_ICInit(TIM4, &TIM_CH1_ICInitStructure);
				is_rising_ch1 = 0;

			}
			else
			{
				pPWM4_1->HighPeriod = TIM_GetCapture1(TIM4);

				TIM_CH1_ICInitStructure.TIM_Channel 		= TIM_Channel_1;
				TIM_CH1_ICInitStructure.TIM_ICPolarity 		= TIM_ICPolarity_Rising;
				TIM_CH1_ICInitStructure.TIM_ICSelection 	= TIM_ICSelection_DirectTI;
				TIM_CH1_ICInitStructure.TIM_ICPrescaler 	= TIM_ICPSC_DIV1;
				TIM_CH1_ICInitStructure.TIM_ICFilter 		= 0x0;
				TIM_ICInit(TIM4, &TIM_CH1_ICInitStructure);
				is_rising_ch1 = 1;
			}

			//To prevent division by 0 on duty cycle calculation
			if ( pPWM4_1->FullPeriod != 0 )
				myPWMCalc(pPWM4_1);


	}
	if (TIM_GetITStatus(TIM4, TIM_IT_CC2) != RESET) {
			tmyPWMInput *pPWM4_2 = &myCTRL.myHW.myPortDCfg.myPWM4_2; //PIN13
			                  // Clear TIM8 Capture Compare1 interrupt pending bit
			TIM_ClearITPendingBit(TIM4, TIM_IT_CC2);

			if ( is_rising_ch2 )
			{
				pPWM4_2->FullPeriod = TIM_GetCapture2(TIM4);

				TIM_CH2_ICInitStructure.TIM_Channel 		= TIM_Channel_2;
				TIM_CH2_ICInitStructure.TIM_ICPolarity 		= TIM_ICPolarity_Falling;
				TIM_CH2_ICInitStructure.TIM_ICSelection 	= TIM_ICSelection_DirectTI;
				TIM_CH2_ICInitStructure.TIM_ICPrescaler 	= TIM_ICPSC_DIV1;
				TIM_CH2_ICInitStructure.TIM_ICFilter 		= 0x0;
				TIM_ICInit(TIM4, &TIM_CH2_ICInitStructure);
				is_rising_ch2 = 0;

			}
			else
			{
				pPWM4_2->HighPeriod = TIM_GetCapture2(TIM4);

				TIM_CH2_ICInitStructure.TIM_Channel 		= TIM_Channel_2;
				TIM_CH2_ICInitStructure.TIM_ICPolarity 		= TIM_ICPolarity_Rising;
				TIM_CH2_ICInitStructure.TIM_ICSelection 	= TIM_ICSelection_DirectTI;
				TIM_CH2_ICInitStructure.TIM_ICPrescaler 	= TIM_ICPSC_DIV1;
				TIM_CH2_ICInitStructure.TIM_ICFilter 		= 0x0;
				TIM_ICInit(TIM4, &TIM_CH2_ICInitStructure);
				is_rising_ch2 = 1;
			}

			//To prevent division by 0 on duty cycle calculation
			if ( pPWM4_2->FullPeriod != 0 )
					myPWMCalc(pPWM4_2);
					
	}

}

[TDK]

Related/duplicate:

Reading two PWM signals using only two channels. - STMicroelectronics Community