用STM32F030的TIM3做38K红外发射
要实现的功能很简单，
要发射高电平1，就把PWM口的pwm置为低电平；
要发低电平0，就在PWM口发送38K的方波。

现在碰到个问题
停止PWM后，想隔2ms再发送pwm，时间就会延迟5.6ms才发送。
只要设的时间小于5.6ms，低电平的时间就会是5.6ms。

今天发现把TIM3->CCR3=0;
改为
TIM3->CCR3=1;
时间间隔就是对的，可是这不能用啊。

求正确的解决办法。
附代码。

//TM3初始化：这部分由CUBE MX生成，实测为38KHz

1. static void MX_TIM3_Init(void)
   
2. {
   
3. 
   
4.   TIM_ClockConfigTypeDef sClockSourceConfig;
   
5.   TIM_MasterConfigTypeDef sMasterConfig;
   
6.   TIM_OC_InitTypeDef sConfigOC;
   
7. 
   
8.   htim3.Instance = TIM3;
   
9.   htim3.Init.Prescaler = 0;
   
10.   htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
    
11.   htim3.Init.Period = 209;
    
12.   htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
    
13.   htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_ENABLE;
    
14.   if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
    
15.   {
    
16.     Error_Handler();
    
17.   }
    
18. 
    
19.   sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
    
20.   if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
    
21.   {
    
22.     Error_Handler();
    
23.   }
    
24. 
    
25.   if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)
    
26.   {
    
27.     Error_Handler();
    
28.   }
    
29. 
    
30.   sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
    
31.   sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
    
32.   if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
    
33.   {
    
34.     Error_Handler();
    
35.   }
    
36. 
    
37.   sConfigOC.OCMode = TIM_OCMODE_PWM1;
    
38.   sConfigOC.Pulse = 0;
    
39.   sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    
40.   sConfigOC.OCFastMode = TIM_OCFAST_ENABLE;
    
41.   if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
    
42.   {
    
43.     Error_Handler();
    
44.   }
    
45. 
    
46.   HAL_TIM_MspPostInit(&htim3);
    
47. 
    
48. }
    
49. 
    
50. 
    

复制代码

//开关PWM波形

1. IR_send_Count_time=40;//4ms 低电平
   
2. TIM3->CCR3=70;//IR发低电平
   
3. while(IR_send_Count_time);//<span style="font-size: 13.63636302948px; line-height: 19.0909080505371px;">IR_send_Count_time在定时器中断里减，每100us减1</span>
   
4. 
   
5. IR_send_Count_time=40;//4ms 高电平
   
6. TIM3->CCR3=0;//IR发低电平
   
7. while(IR_send_Count_time);
   
8. 
   
9. IR_send_Count_time=40;//4ms 低电平
   
10. TIM3->CCR3=70;//IR发低电平
    
11. while(IR_send_Count_time);
    
12. 
    
13. IR_send_Count_time=40;//4ms 高电平
    
14. TIM3->CCR3=0;//IR发低电平
    
15. while(IR_send_Count_time);

复制代码

/**
  ******************************************************************************
  * File Name          : main.c
  * Description        : Main program body
  ******************************************************************************
  *
  * COPYRIGHT(c) 2017 STMicroelectronics
  *
  * Redistribution and use in source and binary forms, with or without modification,
  * are permitted provided that the following conditions are met:
  *   1. Redistributions of source code must retain the above copyright notice,
  *      this list of conditions and the following disclaimer.
  *   2. Redistributions in binary form must reproduce the above copyright notice,
  *      this list of conditions and the following disclaimer in the documentation
  *      and/or other materials provided with the distribution.
  *   3. Neither the name of STMicroelectronics nor the names of its contributors
  *      may be used to endorse or promote products derived from this software
  *      without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  ******************************************************************************
  */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "stm32f0xx_hal.h"

uint8_t keyfg;
uint8_t sendfg;
uint8_t button;
uint8_t controlcode[2];
uint8_t compensate;
uint8_t User_code[3]={0x86, 0x79};

/* Private variables ---------------------------------------------------------*/
TIM_HandleTypeDef htim3;

/* USER CODE BEGIN PV */
/* Private variables ---------------------------------------------------------*/

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
void Error_Handler(void);
static void MX_GPIO_Init(void);
static void MX_TIM3_Init(void);                                    
void HAL_TIM_MspPostInit(TIM_HandleTypeDef *htim);

void user_pwm_setvalue(uint16_t value)
{
    TIM_OC_InitTypeDef sConfigOC;
  
    sConfigOC.OCMode = TIM_OCMODE_PWM1;
    sConfigOC.Pulse = value;
    sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
    HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_2);
    HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_2);  
}

void Bit0_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
        HAL_Delay(56);
}

void Bit1_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
        HAL_Delay(168);
}

void Head_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(900);
        user_pwm_setvalue(0);
        HAL_Delay(450);
}

void End_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
        HAL_Delay(56);
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
}

void Encode_SignalGenerate(uint8_t * dat)
{
        uint8_t usercode[2];
        uint8_t i, j;
        usercode[0]=dat[0];
        usercode[1]=dat[1];
        for(j=0; j<2; j++)
        {
                for(i=0; i<8; i++)
                {
                        if(usercode[j]&0x80)
                                Bit1_Encode_SignalGenerate();
                        else
                                Bit0_Encode_SignalGenerate();
                        usercode[j]=usercode[j]<<1;
                }
        }
}

int main(void)
{

  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

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

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* Configure the system clock */
  SystemClock_Config();

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_TIM3_Init();

  /* 启动通道PWM输出 */
  HAL_TIM_PWM_Start(&htim3,TIM_CHANNEL_2);
  user_pwm_setvalue(0);

  controlcode[0]=0xd2;
  controlcode[0]=0x2d;
  while (1)
  {
         Head_Encode_SignalGenerate();
         Encode_SignalGenerate(User_code);
         Encode_SignalGenerate(controlcode);
         End_Encode_SignalGenerate();
         HAL_Delay(4200);
  }

}

/** System Clock Configuration
*/
void SystemClock_Config(void)
{

  RCC_OscInitTypeDef RCC_OscInitStruct;
  RCC_ClkInitTypeDef RCC_ClkInitStruct;

    /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL6;
  RCC_OscInitStruct.PLL.PREDIV = RCC_PREDIV_DIV1;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }

    /**Initializes the CPU, AHB and APB busses clocks
    */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }

    /**Configure the Systick interrupt time
    */
  HAL_SYSTICK_Config(HAL_RCC_GetHCLKFreq()/100000);

    /**Configure the Systick
    */
  HAL_SYSTICK_CLKSourceConfig(SYSTICK_CLKSOURCE_HCLK);

  /* SysTick_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(SysTick_IRQn, 0, 0);
}

/* TIM3 init function */
static void MX_TIM3_Init(void)
{

  TIM_ClockConfigTypeDef sClockSourceConfig;
  TIM_MasterConfigTypeDef sMasterConfig;
  TIM_OC_InitTypeDef sConfigOC;

  htim3.Instance = TIM3;
  htim3.Init.Prescaler = 0;
  htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim3.Init.Period = 1266;
  htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
  {
    Error_Handler();
  }

  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }

  if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)
  {
    Error_Handler();
  }

  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }

  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 633;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
  if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_2) != HAL_OK)
  {
    Error_Handler();
  }

  HAL_TIM_MspPostInit(&htim3);

}

/** Configure pins as
        * Analog
        * Input
        * Output
        * EVENT_OUT
        * EXTI
*/
static void MX_GPIO_Init(void)
{

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOF_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();

}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @param  None
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler */
  /* User can add his own implementation to report the HAL error return state */
  while(1)
  {
  }
  /* USER CODE END Error_Handler */
}

#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 CODE BEGIN 6 */
  /* 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) */
  /* USER CODE END 6 */

}

#endif

/**
  * @}
  */

/**
  * @}
*/

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

/**
  * 函数功能: 通用定时器初始化并配置通道PWM输出
  * 输入参数: 无
  * 返 回 值: 无
  * 说    明: 无
  */
void GENERAL_TIMx_Init(void)
{
        TIM_ClockConfigTypeDef sClockSourceConfig;
        TIM_MasterConfigTypeDef sMasterConfig;
        TIM_OC_InitTypeDef sConfigOC;
  
        htimx.Instance = GENERAL_TIMx;
        htimx.Init.Prescaler = GENERAL_TIM_PRESCALER;
        htimx.Init.CounterMode = TIM_COUNTERMODE_UP;
        htimx.Init.Period = GENERAL_TIM_PERIOD;
        htimx.Init.ClockDivision=TIM_CLOCKDIVISION_DIV1;
        HAL_TIM_Base_Init(&htimx);

        sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
        HAL_TIM_ConfigClockSource(&htimx, &sClockSourceConfig);

        sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
        sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
        HAL_TIMEx_MasterConfigSynchronization(&htimx, &sMasterConfig);
  
        sConfigOC.OCMode = TIM_OCMODE_PWM1;
        sConfigOC.Pulse = GENERAL_TIM_CH1_PULSE;
        sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
        sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
        HAL_TIM_PWM_ConfigChannel(&htimx, &sConfigOC, TIM_CHANNEL_2);

        HAL_TIM_MspPostInit(&htimx);
}

void user_pwm_setvalue(uint16_t value)
{
    TIM_OC_InitTypeDef sConfigOC;
  
    sConfigOC.OCMode = TIM_OCMODE_PWM1;
    sConfigOC.Pulse = value;
    sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
    HAL_TIM_PWM_ConfigChannel(&htimx, &sConfigOC, TIM_CHANNEL_2);
    HAL_TIM_PWM_Start(&htimx, TIM_CHANNEL_2);  
}

void Bit0_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
        HAL_Delay(56);
}

void Bit1_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
        HAL_Delay(168);
}

void Head_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(900);
        user_pwm_setvalue(0);
        HAL_Delay(45);
}

void End_Encode_SignalGenerate(void)
{
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
        HAL_Delay(56);
        user_pwm_setvalue(316);
        HAL_Delay(56);
        user_pwm_setvalue(0);
}

void Usercode_Encode_SignalGenerate(uint8_t * dat)
{
        uint8_t usercode[3];
        uint8_t i, j;
        usercode[0]=dat[0];
        usercode[1]=dat[1];
        usercode[2]=dat[2];
        for(j=0; j<3; j++)
        {
                for(i=0; i<8; i++)
                {
                        if(usercode[j]&0x80)
                                Bit1_Encode_SignalGenerate();
                        else
                                Bit0_Encode_SignalGenerate();
                        usercode[j]=usercode[j]<<1;
                }
        }
}

void Controlcode_Encode_SignalGenerate(uint8_t * dat)
{
        uint8_t i, j;
        for(j=0; j<2; j++)
        {
                for(i=0; i<8; i++)
                {
                        if(dat[j]&0x80)
                                Bit1_Encode_SignalGenerate();
                        else
                                Bit0_Encode_SignalGenerate();
                        dat[j]=dat[j]<<1;
                }
        }
}

#define GENERAL_TIMx                        TIM3
#define GENERAL_TIM_RCC_CLK_ENABLE()        __HAL_RCC_TIM3_CLK_ENABLE()
#define GENERAL_TIM_RCC_CLK_DISABLE()       __HAL_RCC_TIM3_CLK_DISABLE()
#define GENERAL_TIM_GPIO_RCC_CLK_ENABLE()   {__HAL_RCC_GPIOA_CLK_ENABLE();__HAL_RCC_GPIOB_CLK_ENABLE();}
#define GENERAL_TIM_CH1_PORT                GPIOA
#define GENERAL_TIM_CH1_PIN                 GPIO_PIN_6
#define GENERAL_TIM_CH2_PORT                GPIOA
#define GENERAL_TIM_CH2_PIN                 GPIO_PIN_7
#define GENERAL_TIM_CH3_PORT                GPIOB
#define GENERAL_TIM_CH3_PIN                 GPIO_PIN_0
#define GENERAL_TIM_CH4_PORT                GPIOB
#define GENERAL_TIM_CH4_PIN                 GPIO_PIN_1
#define GENERAL_TIM_CH1_AF                  GPIO_AF1_TIM3

//开关PWM波形 这段代码你是用寄存器操作来实现的
建议你用HAL库的函数来实现

奏奏奏 发表于 2017-4-25 17:00
//开关PWM波形 这段代码你是用寄存器操作来实现的
建议你用HAL库的函数来实现 ...

不是用寄存器更加直接吗？

奏奏奏 发表于 2017-4-25 17:00
//开关PWM波形 这段代码你是用寄存器操作来实现的
建议你用HAL库的函数来实现 ...

请教，是用哪个函数来实现呢？
我用过这两个，是不行的，关闭PWM后低电平电压漂移，而且也一样没有解决延迟问题
HAL_TIM_PWM_Start(TIM_HandleTypeDef *htim, uint32_t Channel);
HAL_TIM_PWM_Stop(TIM_HandleTypeDef *htim, uint32_t Channel);

那么我觉得可能是硬件设计问题，建议先查看电路

奏奏奏 发表于 2017-4-25 19:34
那么我觉得可能是硬件设计问题，建议先查看电路

應該不是。
如果是電路的問題，那TIM3->CCR3設爲1應該也會有延遲。

时钟与定时器配置

LIUBEIHUA 发表于 2017-4-26 14:29
时钟与定时器配置

用你给的函数做PWM赋值
结果还是一样的

试着改系统时钟为48M（原来是8M，为了省电），也还是没用。

void user_pwm_setvalue(uint16_t value)
{
    TIM_OC_InitTypeDef sConfigOC;
  
    sConfigOC.OCMode = TIM_OCMODE_PWM1;
    sConfigOC.Pulse = value;
    sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
    sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
    HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_3);
    HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_3);  
}

我的板小不能放晶振用的是内部时钟，用示波器看过可以工作的，采用的是硬石的风格。用TIM3,14,15,17都试过都有脉冲输出。

初始化PWM后
HAL_TIM_PWM_Start(&htimx,TIM_CHANNEL_2);
打开PWM，示波器上就有波形输出，不能关！

  user_pwm_setvalue(0);  用这个关，实际上PWM没关给它低电平。

PWM关就再也打不开了

/**,我只是路过打酱油的，嘿嘿

LIUBEIHUA 发表于 2017-4-26 16:22
初始化PWM后
HAL_TIM_PWM_Start(&htimx,TIM_CHANNEL_2);
打开PWM，示波器上就有波形输出，不能关！

谢谢你的热心回复用这个函数关也是有延迟
HAL_TIM_PWM_Start(&htimx,TIM_CHANNEL_2);
HAL_TIM_PWM_Stop(&htimx,TIM_CHANNEL_2);



user_pwm_setvalue(0);  用这个关掉再打开PWM
关是关了，情况没改善，跟我用寄存器的方式是一样的问题
比如我只要关1ms
实际会关5.6ms

另外我也是内部晶振

来学习下