STM32一定时器产生不同频率的PWM

zero99

平时记性实在太差，调试完的程序，过两天又忘了，往往需要一阵子才能想起来，有时以前的资料找不到了，更是恼火，不得不重复到网上搜索。刚刚调试成功了一个类型的程序，立刻记下来，呵呵，不要又忘记了。

STM32产生PWM是非常的方便的，要需要简单的设置定时器，即刻产生！当然，简单的设置对于新手来产，也是麻烦的，主要包括：

（1）使能定时器时钟：RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);

（2）定义相应的GPIO：

1. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6;
   
2. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //下拉接地，检测输入的高电平
   
3. GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
   
4. GPIO_Init(GPIOA, &GPIO_InitStructure);
   
5. 
   
6. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
   
7. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
   
8. GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
   
9. GPIO_Init(GPIOA, &GPIO_InitStructure);

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（3）如果是产生PWM（频率不变，占空比可变），记得打开PWM控制，在TIM_Configuration()中。

1. TIM_Cmd(TIM3,ENABLE);
   
2. 
   
3. TIM_CtrlPWMOutputs(TIM1,ENABLE);

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利用定时器产生不同频率的PWM

有时候，需要产生不同频率的PWM，这个时候，设置与产生相同PWM的程序，有关键的不一样。

（一） 设置的原理

   利用改变定时器输出比较通道的捕获值，当输出通道捕获值产生中断时，在中断中将捕获值改变，这时， 输出的I/O会产生一个电平翻转，利用这种办法，实现不同频率的PWM输出。

（二）关键设置

在定时器设置中：TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);

在中断函数中：

1. if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
   
2.    {
   
3.    TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
   
4. capture = TIM_GetCapture2(TIM3);
   
5.    TIM_SetCompare2(TIM3, capture + Key_Value);
   
6. }

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一个定时器四个通道，分别产生不同频率（这个例子网上也有）

1. <span style="background-color: white;">vu16 CCR1_Val = 32768;
   
2. vu16 CCR2_Val = 16384;
   
3. vu16 CCR3_Val = 8192;
   
4. vu16 CCR4_Val = 4096;
   
5. 
   
6. void TIM_Configuration(void)
   
7. {
   
8. TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
   
9. TIM_OCInitTypeDef TIM_OCInitStructure;
   
10. 
    
11. RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
    
12. 
    
13. TIM_TimeBaseStructure.TIM_Period = 65535;      
    
14. TIM_TimeBaseStructure.TIM_Prescaler = 2;     
    
15. TIM_TimeBaseStructure.TIM_ClockDivision = 0;
    
16. TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
    
17. 
    
18. TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
    
19. 
    
20. TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;      //PWM模式2
    
21. TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效
    
22. TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
    
23. TIM_OCInitStructure.TIM_Pulse = CCR1_Val;        //占空时间
    
24. TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;    //输出极性
    
25. TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;    //互补端的极性
    
26. TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
    
27. TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
    
28. 
    
29. TIM_OC1Init(TIM2,&TIM_OCInitStructure);        //通道1
    
30. TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);
    
31. 
    
32. TIM_OCInitStructure.TIM_Pulse = CCR2_Val;        //占空时间
    
33. TIM_OC2Init(TIM2,&TIM_OCInitStructure);        //通道2
    
34. TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Disable);
    
35. 
    
36. TIM_OCInitStructure.TIM_Pulse = CCR3_Val;        //占空时间
    
37. TIM_OC3Init(TIM2,&TIM_OCInitStructure);        //通道3
    
38. TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Disable);
    
39. 
    
40. TIM_OCInitStructure.TIM_Pulse = CCR4_Val;        //占空时间
    
41. TIM_OC4Init(TIM2,&TIM_OCInitStructure);        //通道4
    
42. TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Disable);
    
43. 
    
44. TIM_Cmd(TIM2,ENABLE);
    
45. 
    
46. //TIM_CtrlPWMOutputs(TIM2,ENABLE);
    
47. 
    
48. TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
    
49. 
    
50. }
    
51. 
    
52. void GPIO_Configuration(void)
    
53. {
    
54. GPIO_InitTypeDef GPIO_InitStructure;
    
55. 
    
56. RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
    
57. RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
    
58. RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
    
59. RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);
    
60. 
    
61. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;
    
62. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
    
63. GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
    
64. GPIO_Init(GPIOA, &GPIO_InitStructure);
    
65. 
    
66. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
    
67. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
    
68. GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
    
69. GPIO_Init(GPIOB, &GPIO_InitStructure);
    
70. 
    
71. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
    
72. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;  //上拉输入
    
73. GPIO_Init(GPIOA, &GPIO_InitStructure);
    
74. 
    
75. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
    
76. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;  //上拉输入
    
77. GPIO_Init(GPIOC, &GPIO_InitStructure);
    
78. 
    
79. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
    
80. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;  //上拉输入
    
81. GPIO_Init(GPIOB, &GPIO_InitStructure);
    
82. 
    
83. GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
    
84. GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
    
85. GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
    
86. 
    
87. GPIO_Init(GPIOA, &GPIO_InitStructure);
    
88. }
    
89. 
    
90. void NVIC_Configuration(void)
    
91. {
    
92. NVIC_InitTypeDef NVIC_InitStructure;
    
93. 
    
94. NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);
    
95. 
    
96. NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn;
    
97. NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;
    
98. NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
    
99. NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
    
100. NVIC_Init(&NVIC_InitStructure);
     
101. }
     
102. 
     
103. u16 capture = 0;
     
104. extern vu16 CCR1_Val;
     
105. extern vu16 CCR2_Val;
     
106. extern vu16 CCR3_Val;
     
107. extern vu16 CCR4_Val;
     
108. 
     
109. void TIM2_IRQHandler(void)
     
110. {
     
111. 
     
112. 
     
113. if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)
     
114. {
     
115.     TIM_ClearITPendingBit(TIM2, TIM_IT_CC1 );
     
116. capture = TIM_GetCapture1(TIM2);
     
117. TIM_SetCompare1(TIM2, capture + CCR1_Val );
     
118. }
     
119. 
     
120. if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)
     
121. {
     
122.     TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);
     
123. capture = TIM_GetCapture2(TIM2);
     
124.     TIM_SetCompare2(TIM2, capture + CCR2_Val);
     
125. }
     
126. 
     
127. if (TIM_GetITStatus(TIM2, TIM_IT_CC3) != RESET)
     
128. {
     
129.     TIM_ClearITPendingBit(TIM2, TIM_IT_CC3);
     
130. capture = TIM_GetCapture3(TIM2);
     
131.     TIM_SetCompare3(TIM2, capture + CCR3_Val);
     
132. }
     
133. 
     
134. if (TIM_GetITStatus(TIM2, TIM_IT_CC4) != RESET)
     
135. {
     
136.     TIM_ClearITPendingBit(TIM2, TIM_IT_CC4);
     
137. capture = TIM_GetCapture4(TIM2);
     
138.     TIM_SetCompare4(TIM2, capture + CCR4_Val);
     
139. }
     
140. 
     
141. }</span>

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一个定时器一个通道，产生不同频率

其它的设置都一样，就是在主函数中修改一个参数，然后在定时器中断中，根据这个参数，改变频率。

1. <span style="background-color: white;">#include "stm32lib\\stm32f10x.h"
   
2. #include "hal.h"
   
3. volatile u16 Key_Value=1000;  //用于保存按键相应的PWM波占空比值
   
4. int main(void)
   
5. {
   
6. ChipHalInit();
   
7. ChipOutHalInit();
   
8. while(1)
   
9. {
   
10.   if( (!Get_Key_Up)&(!Get_Key_Down)&(!Get_Key_Left)&(!Get_Key_Right)&(!Get_Key_Ctrl) )
    
11.   {
    
12.     Key_Value=12000;
    
13.   }
    
14.   else
    
15.   {
    
16.     if(Get_Key_Up)    //按键前进按下 ,对应1kHz
    
17.     {
    
18.     Key_Value=6000;
    
19.     }
    
20.     else if(Get_Key_Down)  //按键后退按下 ,对应2kHz
    
21.     {
    
22.       Key_Value=3000;
    
23.     }
    
24.     Delay_Ms(20);      //10ms延时
    
25. 
    
26.     if(Get_Key_Left)    //按键左转按下,对应3kHz
    
27.     {
    
28.     Key_Value=2000;
    
29.     }
    
30.     else if(Get_Key_Right) //按键右转按下,对应4kHz
    
31.     {
    
32.       Key_Value=1500;
    
33.     }
    
34.     Delay_Ms(20);      //10ms延时
    
35. 
    
36.     if(Get_Key_Ctrl)    //按键控制按下,对应5kHz
    
37.     {
    
38.       Key_Value=1200;
    
39.     }
    
40.     Delay_Ms(20);      //10ms延时
    
41.   }
    
42. }
    
43. }
    
44. extern volatile u16 Key_Value;
    
45. u16 capture=0;
    
46. void TIM3_IRQHandler(void)
    
47. {
    
48. 
    
49. if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
    
50. {
    
51.     TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
    
52. capture = TIM_GetCapture2(TIM3);
    
53.     TIM_SetCompare2(TIM3, capture + Key_Value);
    
54. }
    
55. }
    
56. void TIM3_Configuration(void)
    
57. {
    
58. TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
    
59. TIM_OCInitTypeDef TIM_OCInitStructure;
    
60. 
    
61. RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
    
62. 
    
63. TIM_TimeBaseStructure.TIM_Prescaler = 5;      //预分频(时钟分频)72M/6=12M
    
64. TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //向上计数
    
65. TIM_TimeBaseStructure.TIM_Period = 65535;        //装载值选择最大
    
66. TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
    
67. TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0;
    
68. TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);
    
69. 
    
70. TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle;      //PWM模式2
    
71. TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效
    
72. TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
    
73. TIM_OCInitStructure.TIM_Pulse = Key_Value;        //占空时间
    
74. TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low;    //输出极性
    
75. TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High;    //互补端的极性
    
76. TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
    
77. TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
    
78. 
    
79. TIM_OC2Init(TIM3,&TIM_OCInitStructure);        //通道2
    
80. TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
    
81. 
    
82. TIM_Cmd(TIM3,ENABLE);
    
83. 
    
84. //TIM_CtrlPWMOutputs(TIM1,ENABLE);
    
85. TIM_ITConfig(TIM3, TIM_IT_CC2 , ENABLE);
    
86. }
    
87. </span>

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转自：牛牛的博客

andypanfan

谢谢  很好的总结！！！！

Paderboy

搬个板凳

Mr.出错

看懂这套路了，不过在cube生成的工程里面还未实现到。。囧