stm32實作直流電機調速

直流電動機調速是指電動機在一定負載的條件下，根據需要，人為地改變電動機的轉速。直流電動機調速調速性能好。所謂“調速性能”，是指電動機在一定負載的條件下，根據需要，人為地改變電動機的轉速。直流電動機可以在重負載條件下，實作均勻、平滑的無級調速，而且調速範圍較寬。

對于普通的直流電機，隻要在電機的兩根線上接上電源電機就轉動，導線反接後，電機就發轉。如果，電機兩端的電壓為額定電壓，則電機滿速運轉，如果電壓為額定電壓的一半，則電機以一般的速度運轉。是以電機調速的手段就是更變電機兩端的電壓，而通常的做法就是通過PWM來實作電機調速。 1 PWM電機調速的原理 所謂PWM就是脈沖寬度調制，對于方波而言，一個完整的周期是由高電平脈沖和低電平脈沖所構成的，高電平所占周期的比例就是占空比。占空比越大的話，那麼波形的平均電壓越大；占空比越小，波形的平均電壓也就越小。是以，如果把PWM信号接在電機的控制端，則通過改變占空比，則實作了電機兩端電壓的調節，由此實作了電機轉速的調節。兩個極端的例子：如果占空比為100%，則電壓最大；如果占空比為0，則電壓為0。

電機調速簡單電路的實作，隻控制電機一個方向的調速時，可以通過如下的電路模型來實作。在選型時需要根據電流大小、電壓大小來合理選擇三極管的型号。 在三極管的控制端，調節PWM的占空比可以實作調節電機兩端電壓的大小，進而實作了調速功能。

為了控制電機的正轉和反轉，可以設計一個H橋驅動電路來實作電機正轉和反轉，并實作調速。項目使用stm32輸出PWM波控制L298N實作電機驅動具體電路如下

關鍵代碼如下

void TIM_Config(void)
{
  GPIO_InitTypeDef GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef	TIM_TimeBaseInitStruct;
	TIM_OCInitTypeDef  TIM_OCInitStructure;
	TIM_BDTRInitTypeDef TIM_BDTRInitStructure;
	
	NVIC_InitTypeDef NVIC_InitStructure;
	
	// ¿ªÆô¶¨Ê±Æ÷ʱÖÓ,¼´ÄÚ²¿Ê±ÖÓCK_INT=72M
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_TIM1, ENABLE);
	
   // Êä³ö±È½ÏͨµÀ1 GPIO ³õʼ»¯
	GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_8 | GPIO_Pin_9  ;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOA, &GPIO_InitStructure);
		
	GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_13 | GPIO_Pin_14 ;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);
	GPIO_SetBits(GPIOB, GPIO_Pin_13);
	GPIO_ResetBits(GPIOB, GPIO_Pin_14);
	
	TIM_DeInit(TIM1);        //½«ÍâÉèTIM1¼Ä´æÆ÷ÖØÉèΪȱʡֵ  
	TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1 ;    //ÉèÖÃÁËʱÖÓ·Ö¸î(Tck_tim) 
	TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up ;   //Ñ¡ÔñÁ˼ÆÊýÆ÷ģʽ(TIMÏòÉϼÆÊýģʽ)  
	TIM_TimeBaseInitStruct.TIM_Period = 6005 ;       //É趨¼ÆÊýÆ÷×Ô¶¯ÖØ×°Öµ,È¡Öµ·¶Î§0x0000~0xFFFF   
	TIM_TimeBaseInitStruct.TIM_Prescaler = 71 ;    //ÉèÖÃÓÃÀ´×÷ΪTIM3ʱÖÓƵÂʳýÊýµÄÔ¤·ÖƵֵΪ(79+1),È¡Öµ·¶Î§0x0000~0xFFFF 
	TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStruct ) ;       
	
	/* ¶¨Ê±Æ÷Êä³öͨµÀ1ģʽÅäÖà */
 
  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;/* ģʽÅäÖãºPWMģʽ1 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;	 /* Êä³ö״̬ÉèÖãºÊ¹ÄÜÊä³ö */
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; /* »¥²¹Í¨µÀÊä³ö״̬ÉèÖãºÊ¹ÄÜÊä³ö */
  TIM_OCInitStructure.TIM_Pulse = 3000;/* ÉèÖÃÌø±äÖµ£¬µ±¼ÆÊýÆ÷¼ÆÊýµ½Õâ¸öֵʱ£¬µçƽ·¢ÉúÌø±ä */
  
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;/* µ±¶¨Ê±Æ÷¼ÆÊýֵСÓÚCCR1_ValʱΪ¸ßµçƽ */
  TIM_OCInitStructure.TIM_OCNPolarity= TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCNIdleState_Reset;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
  
  TIM_OC1Init(TIM1, &TIM_OCInitStructure);
  
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;/* ģʽÅäÖãºPWMģʽ1 */
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;	 /* Êä³ö״̬ÉèÖãºÊ¹ÄÜÊä³ö */
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; /* »¥²¹Í¨µÀÊä³ö״̬ÉèÖãºÊ¹ÄÜÊä³ö */
  TIM_OCInitStructure.TIM_Pulse = 3000;/* ÉèÖÃÌø±äÖµ£¬µ±¼ÆÊýÆ÷¼ÆÊýµ½Õâ¸öֵʱ£¬µçƽ·¢ÉúÌø±ä */
	
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;/* µ±¶¨Ê±Æ÷¼ÆÊýֵСÓÚCCR1_ValʱΪ¸ßµçƽ */
  TIM_OCInitStructure.TIM_OCNPolarity= TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCNIdleState_Reset;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Reset;
	
	TIM_OC2Init(TIM1, &TIM_OCInitStructure);
 
 
  /* Automatic Output enable, Break, dead time and lock configuration*/
  TIM_BDTRInitStructure.TIM_OSSRState = TIM_OSSRState_Enable;
  TIM_BDTRInitStructure.TIM_OSSIState = TIM_OSSIState_Enable;
  TIM_BDTRInitStructure.TIM_LOCKLevel = TIM_LOCKLevel_OFF;
  TIM_BDTRInitStructure.TIM_DeadTime = 5;
  TIM_BDTRInitStructure.TIM_Break = TIM_Break_Disable;
  TIM_BDTRInitStructure.TIM_BreakPolarity = TIM_BreakPolarity_High;
  TIM_BDTRInitStructure.TIM_AutomaticOutput = TIM_AutomaticOutput_Enable;
  TIM_BDTRConfig(TIM1, &TIM_BDTRInitStructure);
  
  TIM_OC1PreloadConfig(TIM1,TIM_OCPreload_Enable);
  TIM_OC2PreloadConfig(TIM1,TIM_OCPreload_Enable);
 
	
  TIM_ARRPreloadConfig(TIM1, ENABLE);/* ʹÄܶ¨Ê±Æ÷ÖØÔؼĴæÆ÷ARR */
  TIM_Cmd(TIM1, ENABLE);/* ʹÄܶ¨Ê±Æ÷ */
  TIM_CtrlPWMOutputs(TIM1, ENABLE); /* TIMÖ÷Êä³öʹÄÜ */
  
  TIM_CCxCmd(TIM1,TIM_Channel_1,TIM_CCx_Enable);
  TIM_CCxNCmd(TIM1,TIM_Channel_1,TIM_CCxN_Enable);
  TIM_CCxCmd(TIM1,TIM_Channel_2,TIM_CCx_Enable);
  TIM_CCxNCmd(TIM1,TIM_Channel_2,TIM_CCxN_Enable);
 
}