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I would to like to count event using hardware timer in an STM32F407 -Disco board when 12000 even happen reset counter and again start to count from zero. Set counter to zero One event happen increment counter, second event happen increment counter up to 12000 event than reset counter and start counting from zero.
How to configure timer as counter to count event 120000
How to configure timer as counter to count event 120000
Code:
/**
******************************************************************************
* @file TIM_TimeBase/main.c
* @author MCD Application Team
* @version V1.0.1
* @date 15-May-2012
* @brief Main program body
******************************************************************************
* @attention
*
* <h2><center>© COPYRIGHT 2012 STMicroelectronics</center></h2>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the "License");
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include "stm32f4_discovery.h"
/** @addtogroup STM32F4_Discovery_Peripheral_Examples
* @{
*/
/** @addtogroup TIM_TimeBase
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
__IO uint16_t CCR1_Val = 54618;
__IO uint16_t CCR2_Val = 27309;
__IO uint16_t CCR3_Val = 13654;
__IO uint16_t CCR4_Val = 6826;
uint16_t PrescalerValue = 0;
/* Private function prototypes -----------------------------------------------*/
void TIM_Config(void);
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program
* @param None
* @retval None
*/
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();
/* -----------------------------------------------------------------------
TIM3 Configuration: Output Compare Timing Mode:
In this example TIM3 input clock (TIM3CLK) is set to 2 * APB1 clock (PCLK1),
since APB1 prescaler is different from 1.
TIM3CLK = 2 * PCLK1
PCLK1 = HCLK / 4
=> TIM3CLK = HCLK / 2 = SystemCoreClock /2
To get TIM3 counter clock at 50 MHz, the prescaler is computed as follows:
Prescaler = (TIM3CLK / TIM3 counter clock) - 1
Prescaler = ((SystemCoreClock /2) /50 MHz) - 1
CC1 update rate = TIM3 counter clock / CCR1_Val = 9.154 Hz
==> Toggling frequency = 4.57 Hz
C2 update rate = TIM3 counter clock / CCR2_Val = 18.31 Hz
==> Toggling frequency = 9.15 Hz
CC3 update rate = TIM3 counter clock / CCR3_Val = 36.62 Hz
==> Toggling frequency = 18.31 Hz
CC4 update rate = TIM3 counter clock / CCR4_Val = 73.25 Hz
==> Toggling frequency = 36.62 Hz
Note:
SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f4xx.c file.
Each time the core clock (HCLK) changes, user had to call SystemCoreClockUpdate()
function to update SystemCoreClock variable value. Otherwise, any configuration
based on this variable will be incorrect.
----------------------------------------------------------------------- */
/* Compute the prescaler value */
PrescalerValue = (uint16_t) ((SystemCoreClock / 2) / 500000) - 1;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* Prescaler configuration */
TIM_PrescalerConfig(TIM3, PrescalerValue, TIM_PSCReloadMode_Immediate);
/* Output Compare Timing Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Timing Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Timing Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Timing Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;
TIM_OC4Init(TIM3, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* TIM Interrupts enable */
TIM_ITConfig(TIM3, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);
while (1);
}
/**
* @brief Configure the TIM IRQ Handler.
* @param None
* @retval None
*/
void TIM_Config(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
/* Enable the TIM3 gloabal Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* Initialize Leds mounted on STM32F4-Discovery board */
STM_EVAL_LEDInit(LED4);
STM_EVAL_LEDInit(LED3);
STM_EVAL_LEDInit(LED5);
STM_EVAL_LEDInit(LED6);
/* Turn on LED4, LED3, LED5 and LED6 */
STM_EVAL_LEDOn(LED4);
STM_EVAL_LEDOn(LED3);
STM_EVAL_LEDOn(LED5);
STM_EVAL_LEDOn(LED6);
}
#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****/
