Posted on August 14, 2015 at 03:43I am trying to use TIM4 in external counting mode, I have managed to configure it in external counting mode, but the count I am getting in watch 1 window is random. I am using ground pin of board to give input to PB7 and I expect it should give me one increment in the count when I remove it. but it is not so, can anyone tell me what wrong in my code. (Similar problem was posted in some other thread but could not find exact solution)
I want to get count of rising pulses from external signal:
My Program is:
Main.c
/******************************************** */
/* Includes ------------------------------------------------------------------*/
#include ''stm32f4_discovery.h''
TIM_ICInitTypeDef TIM_ICInitStructure;
uint32_t aa = 0;
/* Private function prototypes -----------------------------------------------*/
void TIM_Config(void);
/* Private functions ---------------------------------------------------------*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f4xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f4xx.c file
*/
/* TIM Configuration */
TIM_Config();
while (1)
{
aa=TIM4->CNT;
}
}
/**
* @brief Configure the TIM4 Pins.
* @param None
* @retval None
*/
void TIM_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* TIM4 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
/* GPIOB clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
/* TIM4 chennel2 configuration : PB.07 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Connect TIM pin to AF2 */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_TIM4);
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
TIM_TIxExternalClockConfig(TIM4, TIM_TIxExternalCLK1Source_TI2, TIM_ICPolarity_Rising, 0);
TIM_Cmd(TIM4, ENABLE);
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d\r\n'', file, line) */
while (1)
{}
}
#endif
/**
* @}
*/
/**
* @}
*/
/******************* (C) COPYRIGHT 2011 STMicroelectronics *****END OF FILE****/
