STM32 一个定时器一个通道，产生不同频率按键变换占空比的问题谢谢了

flame1234 · 发表于 2012-10-5 22:51:32

通过按键我按一下通过LED1 观察是否按下按键那个占空比就改变了就是实现这个功能
下面是程序改变的TIM3的通道1 未按下时是产生 25/250=10%的占空比预想的是按键后产生200/250=80%的占空比我怀疑是TIM3的中断写的有问题当然也可能不是这个问题谢谢你们了
//*************main.c
#include "stm32f10x.h"
#include "gpio.h"
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
uint16_t PrescalerValue = 0;
unsigned short Temp,key_value=25;
/* Private function prototypes -----------------------------------------------*/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
/* Private functions ---------------------------------------------------------*/

/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/* System Clocks Configuration */
RCC_Configuration();

/* GPIO Configuration */
GPIO_Configuration();
NVIC_Configuration();
gpio_init();
/* -----------------------------------------------------------------------
    TIM3 Configuration: generate 4 PWM signals with 4 different duty cycles:
    The TIM3CLK frequency is set to SystemCoreClock (Hz), to get TIM3 counter
    clock at 24 MHz the Prescaler is computed as following:
     - Prescaler = (TIM3CLK / TIM3 counter clock) - 1
    SystemCoreClock is set to 72 MHz for Low-density, Medium-density, High-density
    and Connectivity line devices and to 24 MHz for Low-Density Value line and
    Medium-Density Value line devices

    The TIM3 is running at 36 KHz: TIM3 Frequency = TIM3 counter clock/(ARR + 1)
                                                  = 24 MHz / 666 = 36 KHz
    TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
    TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 37.5%
    TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 25%
    TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 12.5%
----------------------------------------------------------------------- */
/* Compute the prescaler value */
PrescalerValue = (uint16_t) (SystemCoreClock / 250000) - 1;   //1KHZ的周期的PWM
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 249;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;

TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);

/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = key_value;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;

TIM_OC1Init(TIM3, &TIM_OCInitStructure);

TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);

TIM_ARRPreloadConfig(TIM3, ENABLE);

/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);

TIM_ITConfig(TIM3, TIM_IT_CC1 , ENABLE);   //!!!!!!!!

while (1)
{
      Temp = GPIO_ReadInputData(GPIOA); //读取PE输入端口值
      Temp &= 0xA000; //屏蔽掉高9位，只留下需要的低7位

      if(Temp == 0x2000)    //如果K1按键按下
    {
      key_value=200;
   LED1ON();
         //GPIO_ResetBits(GPIOA, GPIO_Pin_8); //清PE0为0，点亮LED1灯
       }
   else
       LED1OFF();
}
}

void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);

NVIC_InitStructure.NVIC_IRQChannel=TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority=2;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(&NVIC_InitStructure);
}

/**
* @brief Configures the different system clocks.
* @param None
* @retval None
*/
void RCC_Configuration(void)
{
/* TIM3 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

/* GPIOA and GPIOB clock enable */
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB |
RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
}

/**
* @brief Configure the TIM3 Ouput Channels.
* @param None
* @retval None
*/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;

/* GPIOA Configuration:TIM3 Channel1, 2, 3 and 4 as alternate function push-pull */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;

GPIO_Init(GPIOA, &GPIO_InitStructure);

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
GPIO_Init(GPIOB, &GPIO_InitStructure);
//#endif
}

#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

下面是stm32f10x_it.c     TIM3中断函数
void TIM3_IRQHandler(void)
{
   if (TIM_GetITStatus(TIM3, TIM_IT_CC1) != RESET)
    {
    TIM_ClearITPendingBit(TIM3, TIM_IT_CC1);
    capture = TIM_GetCapture1(TIM3);
    TIM_SetCompare1(TIM3, capture + key_value);
}
}
谢谢了你们了帮我修改一下程序