STM32F4 Timer Input capture problem
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; }}