TIM_ICPOLARITY_BOTHEDGE Input capture in STM32L

[gerardo]

Posted on November 28, 2014 at 19:24

Hello Guys,

I´m developing an application with STM32L and I would like to use TIM2 Input capture with TIM_ICPOLARITY_BOTHEDGE.When the interrupt occurs...Is there a way of knowing which Polarity has been detected?Maybe it can be able getting the digital value of this channel. If it is high Rising edge has occured. Isn´t it?Is there  some better solution?

[Tesla DeLorean]

Posted on November 28, 2014 at 20:43

Is there some better solution?

Use channel 1 & 2 to catch opposite edges, with channel 2 using TI1 (Timer Input 1)

[gerardo]

Posted on November 28, 2014 at 21:01

I only have one pin to do it

[Tesla DeLorean]

Posted on November 28, 2014 at 21:16

I only have one pin to do it

And so?

[gerardo]

Posted on November 28, 2014 at 21:45

I dont understand your answer sorry :(

[Tesla DeLorean]

Posted on November 28, 2014 at 22:02

Perhaps a diagram from the

http://www.st.com/st-web-ui/static/active/en/resource/technical/document/reference_manual/CD00240193.pdf

might help... One pin, Two channels, Capturing opposite edges of the same Input. Each edge time stamps against the Time Base, Each generates a uniquely identifiable IRQ.

[gerardo]

Posted on November 28, 2014 at 22:10

Once again the correct answer. Thank you so much clive

[gerardo]

Posted on November 28, 2014 at 22:40

Is this configuration correct??GPIO_InitStruct.Pin =  GPIO_PIN_2;GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;GPIO_InitStruct.Pull = GPIO_PULLUP;GPIO_InitStruct.Speed = GPIO_SPEED_HIGH;GPIO_InitStruct.Alternate = GPIO_AF2_TIM2;

¿How can I remap my PA2 pint to Alternate function CH4?

HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);voidHAL_TIMInit(void){       // Enable TIM2 Clock    __TIM2_CLK_ENABLE();        // Timer configuration    TimHandle.Instance           = TIM2;    TimHandle.Init.Period        = T2_FULL_SCALE;    TimHandle.Init.Prescaler     = T2_PSC;    TimHandle.Init.ClockDivision = 0;    TimHandle.Init.CounterMode   = TIM_COUNTERMODE_UP;    HAL_TIM_IC_Init(&TimHandle);        // Configure the Input Capture of channel 3 (PA2)    sICConfig.ICPolarity  = TIM_ICPOLARITY_FALLING;    sICConfig.ICSelection = TIM_ICSELECTION_DIRECTTI;    sICConfig.ICPrescaler = TIM_ICPSC_DIV1;    sICConfig.ICFilter    = 0; //0x03; // Input filter for 8 clock Cycles    HAL_TIM_IC_ConfigChannel(&TimHandle, &sICConfig, TIM_CHANNEL_3);        // Set the TIM2 global Interrupt    HAL_NVIC_SetPriority(TIM2_IRQn, 0, 1);      // Enable the TIM2 global Interrupt    HAL_NVIC_EnableIRQ(TIM2_IRQn);        // Start the Input Capture in interrupt mode    HAL_TIM_IC_Start_IT(&TimHandle, TIM_CHANNEL_3);    HAL_TIM_IC_Start_IT(&TimHandle, TIM_CHANNEL_4);}

¿How can I configure CH4 with rising polarity?