pwm占空比来调节转速啊，就是把触发反转的时间周期改变一下就能调节速度了
TM32有高级定时器TIM1和TIM8,都可以产生六路互补的PWM,还可以插入硬件死区,用于三相电机是很方便的。
STM32系列基于专为要求高性能、低成本、低功耗的嵌入式应用专门设计的ARM Cortex-0内核(ST's product portfolio contains a comprehensive range of microcontrollers, from robust, low-cost 8-bit MCUs up to 32-bit ARM-based Cortex®-M0 and M0+, Cortex®-M3, Cortex®-M4 Flash microcontrollers with a great choice of peripherals. ST has also extended this range to include an ultra-low-power MCU platform) 。按内核架构分为不同产品:
其中STM32F1系列有:
STM32F103"增强型"系列
STM32F101"基本型"系列
STM32F105、STM32F107"互联型"系列
增强型系列时钟频率达到72MHz，是同类产品中性能最高的产品;基本型时钟频率为36MHz，以16位产品的价格得到比16位产品大幅提升的性能，是32位产品用户的最佳选择。两个系列都内置32K到128K的闪存，不同的是SRAM的最大容量和外设接口的组合。时钟频率72MHz时，从闪存执行代码，STM32功耗36mA，是32位市场上功耗最低的产品，相当于0.5mA/MHz。
将stm32的pwm放大的方法是控制输出电平的大小。stm32的IO输出的pwm幅度是固定的，一般就是VCC电压，是不能直接改变pwm的幅度大小的，要改变pwm的幅度大小，一般是要通过电平转换芯片，然后控制输出电平的大小，实现一个pwm的幅度改变。
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讲，也是麻烦的，主要包括：
（1）使能定时器时钟：
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
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（2）定义相应的GPIO：
/* PA2,3,4,5,6输出-Key_Up,Key_Down,Key_Left,Key_Right,Key_Ctrl */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //下拉接地，检测输入的高电平
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, GPIO_InitStructure);
/* PA7用于发出PWM波,即无线数据传送 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
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。
TIM_Cmd(TIM3,ENABLE);
/* TIM1 Main Output Enable */
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);
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在中断函数中：
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
capture = TIM_GetCapture2(TIM3);
TIM_SetCompare2(TIM3, capture + Key_Value);
}
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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）
vu16 CCR1_Val = 32768;
vu16 CCR2_Val = 16384;
vu16 CCR3_Val = 8192;
vu16 CCR4_Val = 4096;void TIM_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
/* TIM2 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
/* ---------------------------------------------------------------
TIM2 Configuration: Output Compare Toggle Mode:
TIM2CLK = 36 MHz, Prescaler = 0x2, TIM2 counter clock = 12 MHz
CC1 update rate = TIM2 counter clock / CCR1_Val = 366.2 Hz
CC2 update rate = TIM2 counter clock / CCR2_Val = 732.4 Hz
CC3 update rate = TIM2 counter clock / CCR3_Val = 1464.8 Hz
CC4 update rate = TIM2 counter clock / CCR4_Val = 2929.6 Hz
--------------------------------------------------------------- *//* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 2;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM2, TIM_TimeBaseStructure);/* Channel 1 Configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; //PWM模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //占空时间
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High; //互补端的极性
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;TIM_OC1Init(TIM2,TIM_OCInitStructure); //通道1
TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Disable);TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //占空时间
TIM_OC2Init(TIM2,TIM_OCInitStructure); //通道2
TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Disable);TIM_OCInitStructure.TIM_Pulse = CCR3_Val; //占空时间
TIM_OC3Init(TIM2,TIM_OCInitStructure); //通道3
TIM_OC3PreloadConfig(TIM2, TIM_OCPreload_Disable);TIM_OCInitStructure.TIM_Pulse = CCR4_Val; //占空时间
TIM_OC4Init(TIM2,TIM_OCInitStructure); //通道4
TIM_OC4PreloadConfig(TIM2, TIM_OCPreload_Disable);
/* TIM2 counter enable */
TIM_Cmd(TIM2,ENABLE);
/* TIM2 Main Output Enable */
//TIM_CtrlPWMOutputs(TIM2,ENABLE);/* TIM IT enable */
TIM_ITConfig(TIM2, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);}void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;/*允许总线CLOCK,在使用GPIO之前必须允许相应端的时钟.
从STM32的设计角度上说,没被允许的端将不接入时钟,也就不会耗能,
这是STM32节能的一种技巧,*/
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC, ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOD, ENABLE);
/* PA2,3,4,5,6,7输出-LED1,LED2,LED3,LED4,LED5,LED6 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_2|GPIO_Pin_3|GPIO_Pin_4|GPIO_Pin_5|GPIO_Pin_6|GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOA, GPIO_InitStructure);
/* PB0,1输出-LED7,LED8*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_OD; //开漏输出
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //50M时钟速度
GPIO_Init(GPIOB, GPIO_InitStructure);
/* PA0,1-KEY_LEFT,KEY_RIGHT*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_1;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
GPIO_Init(GPIOA, GPIO_InitStructure);/* PC13-KEY_UP*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_13;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
GPIO_Init(GPIOC, GPIO_InitStructure);/* PB5-KEY_DOWN*/
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU; //上拉输入
GPIO_Init(GPIOB, GPIO_InitStructure);/* GPIOA Configuration:TIM2 Channel1, 2, 3 and 4 in Output */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOA, GPIO_InitStructure);
}void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;/* Configure one bit for preemption priority */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_1);NVIC_InitStructure.NVIC_IRQChannel=TIM2_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority=0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority=1;
NVIC_InitStructure.NVIC_IRQChannelCmd=ENABLE;
NVIC_Init(NVIC_InitStructure);
}u16 capture = 0;
extern vu16 CCR1_Val;
extern vu16 CCR2_Val;
extern vu16 CCR3_Val;
extern vu16 CCR4_Val;void TIM2_IRQHandler(void)
{/* TIM2_CH1 toggling with frequency = 183.1 Hz */
if (TIM_GetITStatus(TIM2, TIM_IT_CC1) != RESET)
{
TIM_ClearITPendingBit(TIM2, TIM_IT_CC1 );
capture = TIM_GetCapture1(TIM2);
TIM_SetCompare1(TIM2, capture + CCR1_Val );
}
/* TIM2_CH2 toggling with frequency = 366.2 Hz */
if (TIM_GetITStatus(TIM2, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM2, TIM_IT_CC2);
capture = TIM_GetCapture2(TIM2);
TIM_SetCompare2(TIM2, capture + CCR2_Val);
}/* TIM2_CH3 toggling with frequency = 732.4 Hz */
if (TIM_GetITStatus(TIM2, TIM_IT_CC3) != RESET)
{
TIM_ClearITPendingBit(TIM2, TIM_IT_CC3);
capture = TIM_GetCapture3(TIM2);
TIM_SetCompare3(TIM2, capture + CCR3_Val);
}/* TIM2_CH4 toggling with frequency = 1464.8 Hz */
if (TIM_GetITStatus(TIM2, TIM_IT_CC4) != RESET)
{
TIM_ClearITPendingBit(TIM2, TIM_IT_CC4);
capture = TIM_GetCapture4(TIM2);
TIM_SetCompare4(TIM2, capture + CCR4_Val);
}}
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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。
#include "stm32lib\\stm32f10x.h"
#include "hal.h"volatile u16 Key_Value=1000; //用于保存按键相应的PWM波占空比值
int main(void)
{
ChipHalInit();
ChipOutHalInit();while(1)
{
if( (!Get_Key_Up)(!Get_Key_Down)(!Get_Key_Left)(!Get_Key_Right)(!Get_Key_Ctrl) )
{
Key_Value=12000;
}
else
{
if(Get_Key_Up) //按键前进按下 ,对应1kHz
{
Key_Value=6000;
}
else if(Get_Key_Down) //按键后退按下 ,对应2kHz
{
Key_Value=3000;
}
Delay_Ms(20); //10ms延时if(Get_Key_Left) //按键左转按下,对应3kHz
{
Key_Value=2000;
}
else if(Get_Key_Right) //按键右转按下,对应4kHz
{
Key_Value=1500;
}
Delay_Ms(20); //10ms延时if(Get_Key_Ctrl) //按键控制按下,对应5kHz
{
Key_Value=1200;
}
Delay_Ms(20); //10ms延时
}
}
}extern volatile u16 Key_Value;
u16 capture=0;
void TIM3_IRQHandler(void)
{
/* TIM2_CH2 toggling with frequency = 366.2 Hz */
if (TIM_GetITStatus(TIM3, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_CC2);
capture = TIM_GetCapture2(TIM3);
TIM_SetCompare2(TIM3, capture + Key_Value);
}
}void TIM3_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;/* TIM2 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);/*TIM1时钟配置*/
TIM_TimeBaseStructure.TIM_Prescaler = 5; //预分频(时钟分频)72M/6=12M
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数
TIM_TimeBaseStructure.TIM_Period = 65535; //装载值选择最大
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_RepetitionCounter = 0x0;
TIM_TimeBaseInit(TIM3,TIM_TimeBaseStructure);/* Channel 1 Configuration in PWM mode */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Toggle; //PWM模式2
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //正向通道有效
TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Disable;//反向通道无效
TIM_OCInitStructure.TIM_Pulse = Key_Value; //占空时间
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性
TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_High; //互补端的极性
TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;
TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;TIM_OC2Init(TIM3,TIM_OCInitStructure); //通道2
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* TIM1 counter enable */
TIM_Cmd(TIM3,ENABLE);
/* TIM1 Main Output Enable */
//TIM_CtrlPWMOutputs(TIM1,ENABLE);
TIM_ITConfig(TIM3, TIM_IT_CC2 , ENABLE);
}
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注意：在计算PWM频率的时候，TIMx的时钟都是72Mhz，分频后，因为翻转两次才能形成一个PWM波，因为，PWM的频率是捕获改变频率的1/2。
本文标签：stm32pwm加减速
