(已解决)pwm波的输出电压总是高一倍怎么回事啊,是不是我的程序写错了

thy110

pwm波的输出电压总是高一倍怎么回事啊，我自己写了一下pwm的程序，但是测量时电压总是不对，我设置100的占空比理应输出0.32v但是实际数出0.63v其他的也是一样大一倍，下面是我写的程序

1. static void TIM5_GPIO_Config(void)
   
2. {
   
3.   GPIO_InitTypeDef GPIO_InitStructure;
   
4. 
   
5.   /* TIM3 clock enable */
   
6.   //PCLK1¾­¹ý2±¶Æµºó×÷ΪTIM2µÄʱÖÓÔ´µÈÓÚ72MHz
   
7.   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM5, ENABLE);
   
8. 
   
9.   /* GPIOA and GPIOB clock enable */
   
10.   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
    
11. 
    
12.   /*GPIOA Configuration: TIM2 channel 1 AND 2 and  3 and 4 as alternate function push-pull */
    
13.   GPIO_InitStructure.GPIO_Pin =   GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    
14.   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;        // ¸´ÓÃÍÆÍìÊä³ö
    
15.   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    
16. 
    
17.   GPIO_Init(GPIOA, &GPIO_InitStructure);
    
18. }
    
19. static void TIM5_Mode_Config(void)
    
20. {
    
21.   TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    
22. 
    
23.   /* Time base configuration */     
    
24.   TIM_TimeBaseStructure.TIM_Period = 999;       //µ±¶¨Ê±Æ÷´Ó0¼ÆÊýµ½999£¬¼´Îª1000´Î£¬ÎªÒ»¸ö¶¨Ê±ÖÜÆÚ
    
25.   TIM_TimeBaseStructure.TIM_Prescaler = 0;      //ÉèÖÃÔ¤·ÖƵ£º²»Ô¤·ÖƵ£¬¼´Îª72MHz
    
26.   TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ;  //ÉèÖÃʱÖÓ·ÖƵϵÊý£º²»·ÖƵ
    
27.   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //ÏòÉϼÆÊýģʽ
    
28. 
    
29.   TIM_TimeBaseInit(TIM5, &TIM_TimeBaseStructure);
    
30. }
    
31. 
    
32. void TIM5_Mode1_Config(u16 CCR1_Val)
    
33. {
    
34.   TIM_OCInitTypeDef  TIM_OCInitStructure;
    
35.   
    
36.   TIM5_Mode_Config();
    
37.   
    
38.   /* PWM1 Mode configuration: Channel1 */
    
39.   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;      //ÅäÖÃΪPWMģʽ1
    
40.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;  
    
41.   TIM_OCInitStructure.TIM_Pulse = CCR1_Val;     //ÉèÖÃÌø±äÖµ£¬µ±¼ÆÊýÆ÷¼ÆÊýµ½Õâ¸öֵʱ£¬µçƽ·¢ÉúÌø±ä
    
42.   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;  //µ±¶¨Ê±Æ÷¼ÆÊýֵСÓÚCCR1_ValʱΪ¸ßµçƽ
    
43. 
    
44.   TIM_OC1Init(TIM5, &TIM_OCInitStructure);    //ʹÄÜͨµÀ2
    
45. 
    
46.   TIM_OC1PreloadConfig(TIM5, TIM_OCPreload_Enable);
    
47.    TIM_ARRPreloadConfig(TIM5, ENABLE);       // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
    
48.     /* TIM3 enable counter */
    
49.   TIM_Cmd(TIM5, ENABLE);                   //ʹÄܶ¨Ê±Æ÷3  
    
50. 
    
51. }
    
52. void TIM5_Mode2_Config(u16 CCR2_Val)
    
53. {
    
54.   TIM_OCInitTypeDef  TIM_OCInitStructure;
    
55.   TIM5_Mode_Config();
    
56.   /* PWM1 Mode configuration: Channel2 */
    
57.   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;      //ÅäÖÃΪPWMģʽ1
    
58.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
59.   TIM_OCInitStructure.TIM_Pulse = CCR2_Val;    //ÉèÖÃͨµÀ2µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
    
60. 
    
61.   TIM_OC2Init(TIM5, &TIM_OCInitStructure);    //ʹÄÜͨµÀ2
    
62. 
    
63.   TIM_OC2PreloadConfig(TIM5, TIM_OCPreload_Enable);
    
64.    TIM_ARRPreloadConfig(TIM5, ENABLE);       // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
    
65.     /* TIM3 enable counter */
    
66.   TIM_Cmd(TIM5, ENABLE);                   //ʹÄܶ¨Ê±Æ÷3  
    
67. }
    
68. void TIM5_Mode3_Config(u16 CCR3_Val)
    
69. {
    
70.   TIM_OCInitTypeDef  TIM_OCInitStructure;
    
71.   TIM5_Mode_Config();
    
72.   /* PWM1 Mode configuration: Channel3 */
    
73.   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;      //ÅäÖÃΪPWMģʽ1
    
74.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
75.   TIM_OCInitStructure.TIM_Pulse = CCR3_Val;  //ÉèÖÃͨµÀ3µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
    
76.   TIM_OC3Init(TIM5, &TIM_OCInitStructure);   //ʹÄÜͨµÀ3
    
77.   TIM_OC3PreloadConfig(TIM5, TIM_OCPreload_Enable);
    
78.   TIM_ARRPreloadConfig(TIM5, ENABLE);       // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
    
79.     /* TIM3 enable counter */
    
80.   TIM_Cmd(TIM5, ENABLE);                   //ʹÄܶ¨Ê±Æ÷3  
    
81. }
    
82. void TIM5_Mode4_Config(u16 CCR4_Val)
    
83. {
    
84.   TIM_OCInitTypeDef  TIM_OCInitStructure;
    
85.   TIM5_Mode_Config();
    
86.   /* PWM1 Mode configuration: Channel4 */
    
87.   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;      //ÅäÖÃΪPWMģʽ1
    
88.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
89.   TIM_OCInitStructure.TIM_Pulse = CCR4_Val;  //ÉèÖÃͨµÀ4µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
    
90.   TIM_OC4Init(TIM5, &TIM_OCInitStructure);  //ʹÄÜͨµÀ4
    
91.   
    
92.   TIM_OC4PreloadConfig(TIM5, TIM_OCPreload_Enable);
    
93.   
    
94.   TIM_ARRPreloadConfig(TIM5, ENABLE);       // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
    
95.     /* TIM3 enable counter */
    
96.   TIM_Cmd(TIM5, ENABLE);                   //ʹÄܶ¨Ê±Æ÷3  
    
97. }

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三流电工

用示波器看看

thy110

三流电工 发表于 2014-7-3 09:00
用示波器看看

我只是个学生没有示波器阿

三流电工

软件仿真大概看看

thy110

三流电工 发表于 2014-7-3 12:59
软件仿真大概看看

我试一下。