无刷直流电机比较流行，很多电机内部加入霍尔元件，通过霍尔元件可以知道电机转子的位置，根据这个位置给电机相线供电，这样电机就转起来了。框图如下所示
霍尔元件输出与相线输入电压的关系可以让BLDC电机厂家提供，一般都提供这个对应关系表，如下图所示
有了上面这些足可以让我们设计电路编写程序让电机转起来！
有上面的框图可以看出，3相电机的驱动需要六个mos管，一般用的是NMOS，大功率的NMOS比较便宜。大功率MOS管有较大的结电容，控制电压也高些，无法用单片机直接驱动，所以需要驱动电路。驱动芯片组成的驱动电路比较简单，常见的有IR2110S，我这里用IR2110S设计了MOS驱动电路，如下图所示，其中C24和D5是自举电路，为了控制Q3抬高电压。（然后组成3片IR2110S， 驱动6个NMOS）
霍尔元件供电是5V，他的输出一般也是5V，可以分压后给单片机用。
单片机用流行STM32，他有高级定时器T1，T8，可以输出3对互补的PWM波，还有刹车信号输入，这些特性对于电机的可控制非常合适。电路如下图所示
BLDC电机控制用到单片机定时器及IO中断，初始化部分如下
void TIM_Config(void)
{GPIO_InitTypeDef GPIO_InitStructure;TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStruct;TIM_OCInitTypeDef TIM_OCInitStructure;TIM_BDTRInitTypeDef TIM_BDTRInitStructure;EXTI_InitTypeDef EXTI_InitStructure;//NVIC_InitTypeDef NVIC_InitStructure;TIM_ICInitTypeDef TIM_ICInitStructure;// ¿ªÆô¶¨Ê±Æ÷ʱÖÓ,¼´ÄÚ²¿Ê±ÖÓCK_INT=72MRCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOB | RCC_APB2Periph_TIM1, ENABLE);RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);// Êä³ö±È½ÏͨµÀ1 GPIO ³õʼ»¯GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9 | GPIO_Pin_10 ;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_Pin_15;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;GPIO_Init(GPIOB, &GPIO_InitStructure);//»ô¶ûÊäÈëGPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 ;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_Init(GPIOA, &GPIO_InitStructure);GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 ;GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;GPIO_Init(GPIOB, &GPIO_InitStructure);GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource0);EXTI_InitStructure.EXTI_Line=EXTI_Line0; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init(&EXTI_InitStructure);NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x01;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure);GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource6);EXTI_InitStructure.EXTI_Line= EXTI_Line6; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init(&EXTI_InitStructure);NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x02;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource7);EXTI_InitStructure.EXTI_Line= EXTI_Line7; EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising_Falling;EXTI_InitStructure.EXTI_LineCmd = ENABLE;EXTI_Init(&EXTI_InitStructure);NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0x01; NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0x03;NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE; NVIC_Init(&NVIC_InitStructure); TIM_DeInit(TIM1); //½«ÍâÉèTIM1¼Ä´æÆ÷ÖØÉèΪȱʡֵ TIM_TimeBaseInitStruct.TIM_ClockDivision = TIM_CKD_DIV1 ; TIM_TimeBaseInitStruct.TIM_CounterMode = TIM_CounterMode_Up ; TIM_TimeBaseInitStruct.TIM_Period = 1000 ; TIM_TimeBaseInitStruct.TIM_Prescaler = 3 ; TIM_TimeBaseInitStruct.TIM_RepetitionCounter = 0;TIM_TimeBaseInit(TIM1, &TIM_TimeBaseInitStruct ) ; /* ¶¨Ê±Æ÷Êä³öͨµÀ1ģʽÅäÖà */TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; TIM_OCInitStructure.TIM_OutputNState = TIM_OutputNState_Enable; TIM_OCInitStructure.TIM_Pulse = 1000;TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;TIM_OCInitStructure.TIM_OCNPolarity= TIM_OCNPolarity_High;TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Set;TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCNIdleState_Set;TIM_OC1Init(TIM1, &TIM_OCInitStructure);TIM_OC2Init(TIM1, &TIM_OCInitStructure);TIM_OC3Init(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 = 1;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_OC3PreloadConfig(TIM1,TIM_OCPreload_Enable);TIM_ARRPreloadConfig(TIM1, ENABLE);TIM_Cmd(TIM1, ENABLE);TIM_CtrlPWMOutputs(TIM1, ENABLE); 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);TIM_CCxCmd(TIM1,TIM_Channel_3,TIM_CCx_Enable);TIM_CCxNCmd(TIM1,TIM_Channel_3,TIM_CCxN_Enable);
}让电机转起来需要知道电机转子的位置，根据霍尔相位对应表驱动电机相线，程序里用中断获取霍尔电平的变化。
void EXTI0_IRQHandler(void)
{ int i,j;if(EXTI_GetITStatus(EXTI_Line0)!=RESET){EXTI_ClearITPendingBit(EXTI_Line0);step=((GPIOA->IDR & GPIO_Pin_6)>>6)+((GPIOA->IDR & GPIO_Pin_7)>>6)+((GPIOB->IDR & GPIO_Pin_0)<<2);if(start==1){TIM1->CCER=PHASE_CHANGE[step];int_count1++;}}
}void EXTI9_5_IRQHandler(void)
{ int i,j;if(EXTI_GetITStatus(EXTI_Line6)!=RESET){EXTI_ClearITPendingBit(EXTI_Line6);step=((GPIOA->IDR & GPIO_Pin_6)>>6)+((GPIOA->IDR & GPIO_Pin_7)>>6)+((GPIOB->IDR & GPIO_Pin_0)<<2);if(start==1){TIM1->CCER=PHASE_CHANGE[step];int_count2++;}}if(EXTI_GetITStatus(EXTI_Line7)!=RESET){EXTI_ClearITPendingBit(EXTI_Line7);step=((GPIOA->IDR & GPIO_Pin_6)>>6)+((GPIOA->IDR & GPIO_Pin_7)>>6)+((GPIOB->IDR & GPIO_Pin_0)<<2);if(start==1){TIM1->CCER=PHASE_CHANGE[step];int_count3++;}}
}检测到变化后改变定时器输出，从而使电机相线得到驱动，我在程序里做好了数组，把得到了位置通过数组给定时器CCER寄存器，这样电机就转起来了
int PHASE_CHANGE[7]={0x0000,0x0104,0x0041,0x0140,0x0410,0x0014,0x0401};这是霍尔输出与PWM输出波形的截图
这是定时器3对PWM的输出截图
这是电机和电路板
