求助！我用stm32调38KHz，驱动不了红外发射管！急

壁虎在漫步

我用51单片机调试38kHz可以驱动红外发射管，可以接收。  但是我用stm32调pwm调38KHz就驱动不了，或者说是接收不到。这问题出在哪里呢？手头上只有数字万用表，测出来的频率也是38kHz，
接收头是市面上的38KHz接收头

1. #include "bsp_pwm_output.h"
   
2. 
   
3. 
   
4. static void TIM3_GPIO_Config(void)
   
5. {
   
6.   GPIO_InitTypeDef GPIO_InitStructure;
   
7. 
   
8.         /* ÉèÖÃTIM3CLK Ϊ 72MHZ */
   
9.   RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
   
10. 
    
11.   /* GPIOA and GPIOB clock enable */
    
12.   RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB, ENABLE);
    
13. 
    
14.   /*GPIOA Configuration: TIM3 channel 1 and 2 as alternate function push-pull */
    
15.   GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_6 | GPIO_Pin_7;
    
16.   GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;                    // ¸´ÓÃÍÆÍìÊä³ö
    
17.   GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    
18.   GPIO_Init(GPIOA, &GPIO_InitStructure);
    
19. 
    
20.   /*GPIOB Configuration: TIM3 channel 3 and 4 as alternate function push-pull */
    
21.   GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_0 | GPIO_Pin_1;
    
22.   GPIO_Init(GPIOB, &GPIO_InitStructure);
    
23. }
    
24. 
    
25. 
    
26. static void TIM3_Mode_Config(void)
    
27. {
    
28.         TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
    
29.         TIM_OCInitTypeDef  TIM_OCInitStructure;
    
30. 
    
31.         /* PWMÐźŵçƽÌø±äÖµ */
    
32.         u16 CCR1_Val = 8;        
    
33.         u16 CCR2_Val = 10;
    
34.         u16 CCR3_Val = 13;
    
35.         u16 CCR4_Val = 18;
    
36. 
    
37. 
    
38.   /* Time base configuration */                 
    
39.   TIM_TimeBaseStructure.TIM_Period = 25;       //38kHZ
    
40.   TIM_TimeBaseStructure.TIM_Prescaler = 71;            //ÉèÖÃÔ¤·ÖƵ
    
41.   TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1 ;        //ÉèÖÃʱÖÓ·ÖƵϵÊý£º²»·ÖƵ(ÕâÀïÓò»µ½)
    
42.   TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //ÏòÉϼÆÊýģʽ
    
43.   TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
    
44. 
    
45.   /* PWM1 Mode configuration: Channel1 */
    
46.   TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;            //ÅäÖÃΪPWMģʽ1
    
47.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;       
    
48.   TIM_OCInitStructure.TIM_Pulse = CCR1_Val;           //ÉèÖÃÌø±äÖµ£¬µ±¼ÆÊýÆ÷¼ÆÊýµ½Õâ¸öֵʱ£¬µçƽ·¢ÉúÌø±ä
    
49.   TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;  //µ±¶¨Ê±Æ÷¼ÆÊýֵСÓÚCCR1_ValʱΪ¸ßµçƽ
    
50.   TIM_OC1Init(TIM3, &TIM_OCInitStructure);         //ʹÄÜͨµÀ1
    
51.   TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
52. 
    
53.   /* PWM1 Mode configuration: Channel2 */
    
54.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
55.   TIM_OCInitStructure.TIM_Pulse = CCR2_Val;          //ÉèÖÃͨµÀ2µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
    
56.   TIM_OC2Init(TIM3, &TIM_OCInitStructure);          //ʹÄÜͨµÀ2
    
57.   TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
58. 
    
59.   /* PWM1 Mode configuration: Channel3 */
    
60.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
61.   TIM_OCInitStructure.TIM_Pulse = CCR3_Val;        //ÉèÖÃͨµÀ3µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
    
62.   TIM_OC3Init(TIM3, &TIM_OCInitStructure);         //ʹÄÜͨµÀ3
    
63.   TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
64. 
    
65.   /* PWM1 Mode configuration: Channel4 */
    
66.   TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
    
67.   TIM_OCInitStructure.TIM_Pulse = CCR4_Val;        //ÉèÖÃͨµÀ4µÄµçƽÌø±äÖµ£¬Êä³öÁíÍâÒ»¸öÕ¼¿Õ±ÈµÄPWM
    
68.   TIM_OC4Init(TIM3, &TIM_OCInitStructure);        //ʹÄÜͨµÀ4
    
69.   TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);
    
70.   TIM_ARRPreloadConfig(TIM3, ENABLE);                         // ʹÄÜTIM3ÖØÔؼĴæÆ÷ARR
    
71. 
    
72.   /* TIM3 enable counter */
    
73.   TIM_Cmd(TIM3, ENABLE);                   //ʹÄܶ¨Ê±Æ÷3       
    
74. }
    
75. 
    
76. 
    
77. void TIM3_PWM_Init(void)
    
78. {
    
79.         TIM3_GPIO_Config();
    
80.         TIM3_Mode_Config();       
    
81. }

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壁虎在漫步

要不要上拉5V电阻？

fire

壁虎在漫步 发表于 2015-1-1 21:12
要不要上拉5V电阻？

要接的，亲

漩涡哲

fire 发表于 2015-1-2 10:04
要接的，亲

3.3V上拉也可以的吧  顺便问一下上拉电阻选多大的？？

fire

漩涡哲 发表于 2015-1-2 18:25
3.3V上拉也可以的吧  顺便问一下上拉电阻选多大的？？

10K ，应该是5V上拉

漩涡哲

楼主成功了吗  求共享下电路图  

suqi0396

gg 楼主成功了吗  求共享下电路图