STM32F4 Timer Input capture problem

[RN]

Posted on May 19, 2018 at 12:48

Hello , 

I am using stm32f446re nucleo board . and i face some issue in timer input capture . 

here i am using 2 timers TIM6 ( for time base generation ) and TIM2 (free running input capture purpose)

actually my code is working fine when i run the first timer(TIM6) at 10 micro or 100 micro second time base generation . I actually toggle the gpio in IRQ handler of TIM6 and that is input to the TIM2 input channel where i detect the gap between rising and falling edge of a gpio . TIM2 actually DMA the content of CCR1 to memory . 

as i said this works  fine when i use the TIM6 for 10 micro and 100 micro time base generation 

but when i use the TIM6 for 1 mirco second time base generation , the TIM2 is not giving correct values for the gpio toggling . Can you please help me to understand what is going wrong ?

i am using AHB = 84Mhz, timer clock = 48Mhz. 

Here is a code 

int main(void)

{ /* USER CODE BEGIN 1 */ uint32_t diffCapture=0; double frequency=0; char msg[30];

/* USER CODE END 1 */

/* MCU Configuration----------------------------------------------------------*/

/* Reset of all peripherals, Initializes the Flash interface and the Systick. */

HAL_Init();

/* USER CODE BEGIN Init */

/* USER CODE END Init */

/* Configure the system clock */

SystemClock_Config();

/* USER CODE BEGIN SysInit */

/* USER CODE END SysInit */

/* Initialize all configured peripherals */

MX_GPIO_Init(); MX_DMA_Init(); MX_USART2_UART_Init(); MX_TIM6_Init(); MX_TIM2_Init(); /* USER CODE BEGIN 2 */ HAL_TIM_IC_Start_DMA(&htim2, TIM_CHANNEL_1, (uint32_t*) captures, 2); HAL_TIM_Base_Start_IT(&htim6);

/* USER CODE END 2 */

/* Infinite loop */

/* USER CODE BEGIN WHILE */ while (1) {

   if (captureDone != 0) {

   if (captures[1] >= captures[0])    diffCapture = captures[1] - captures[0];    else    diffCapture = (htim2.Instance->ARR - captures[0]) + captures[1];

   frequency = HAL_RCC_GetPCLK1Freq() / (htim2.Instance->PSC + 1);

   frequency = (float) frequency / diffCapture;

   sprintf(msg, 'Input frequency: %.3f\r\n', frequency);

   //HAL_UART_Transmit(&huart2, (uint8_t*) msg, strlen(msg), HAL_MAX_DELAY);    //while (1); }

}

}

/* TIM2 init function */

static void MX_TIM2_Init(void){

TIM_MasterConfigTypeDef sMasterConfig;

TIM_IC_InitTypeDef sConfigIC;

htim2.Instance = TIM2;

htim2.Init.Prescaler = 0; htim2.Init.CounterMode = TIM_COUNTERMODE_UP; htim2.Init.Period = 65535; htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1; if (HAL_TIM_IC_Init(&htim2) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); }

sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;

sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE; if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); }

sConfigIC.ICPolarity = TIM_INPUTCHANNELPOLARITY_RISING;

sConfigIC.ICSelection = TIM_ICSELECTION_DIRECTTI; sConfigIC.ICPrescaler = TIM_ICPSC_DIV1; sConfigIC.ICFilter = 0; if (HAL_TIM_IC_ConfigChannel(&htim2, &sConfigIC, TIM_CHANNEL_1) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); }

}

/* TIM6 init function */

static void MX_TIM6_Init(void){

TIM_MasterConfigTypeDef sMasterConfig;

htim6.Instance = TIM6;

htim6.Init.Prescaler = 0; htim6.Init.CounterMode = TIM_COUNTERMODE_UP; htim6.Init.Period = 47; if (HAL_TIM_Base_Init(&htim6) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); }

sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;

sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE; if (HAL_TIMEx_MasterConfigSynchronization(&htim6, &sMasterConfig) != HAL_OK) { _Error_Handler(__FILE__, __LINE__); }

}

/* USER CODE BEGIN 4 */

void HAL_TIM_IC_CaptureCallback(TIM_HandleTypeDef *htim) {

if (htim->Channel == HAL_TIM_ACTIVE_CHANNEL_1) { captureDone = 1; }}

[bonmotwang]

A off topic question here.

I am doing a simulator task right now. I found that I cannot use STM32CUBE to generate HAL_TIM_IC_CaptureCallback for TIM15. I am using 32F030.

Did I miss anything?