[Jiangsu University Self-Chemistry Association stm32F103c8t6] Notes [Introduction to 32 MCUs and Using TIM Output to Compare and Configure PWM]

八、OC输出比较

• OC （output compare） 输出比较 比较CNT 和 CCR 寄存器的关系
• IC (input compare) 输入捕获
• CC （capture compare）输入捕获 and output compare unit
  
  
  CNT计数
  CCRis a value we give

九、PWM配置

Afterglow and persistence of human vision（控制LED灯、电机、舵机（pwm作为一种通信协议）等）--------------------------------------->惯性的系统

一般来说,Only use the ones in the red box above

————————————————————————————想要输出PWM波,You need to open the following modules————————————————————————

1、RCC开启时钟

打开TIM外设和GPIO外设时钟

2、配置时基单元

包括前面的时钟源选择 + 时基单元配置
This code was written before

3、配置输出比较单元

里面包括CCR的值、输出比较模式、极性选择、The output enables these parameters,In the library function, it is also configured with a unified structure

4、配置GPIO

把PWM对应的GPIO口,初始化为复用推挽输出的配置（GPIOThe initialization code is used to be placed above）

5、运行控制

启动计数器,这样就能输出PWM了

——————————————————————————————————————————————————————————————

下面展示一下代码（Including remapping）：

#include "stm32f10x.h" // Device header

void PWM_Init(void)
{
       
//RCC开启时钟,和TIMThe same as the timed interrupt

	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);
	
	//RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE); //Pin remapping is usedAFIO,开启AFIO时钟
	
	//GPIO_PinRemapConfig(GPIO_PartialRemap1_TIM2, ENABLE); //Pin remapping configuration　（部分重映射1,使能）　这样就能把PA0换成PA15了 //查表TIM2复用功能重映像
	//GPIO_PinRemapConfig(GPIO_Remap_SWJ_JTAGDisable, ENABLE);//解除JTAG调试端口,可以使用PA15,PB3,PB4（Usually we liftJTAG的调试端口,保留SWD调试端口）,GPIO_PinRemapConfig（）is the remapping function



//总结：如果你想让PA15、PB3、PB4These three pins are treated as GPIO来使用的话,Just add the comment above1、3句,先打开AFIO,再用AFIO将JTAGmultiplex release
// If you want to remap the multiplexed pins of timers or other peripherals,Then add the commented out above1、2句,先打开AFIO,再用AFIORemap pins multiplexed by peripherals
// If the pin you remapped happens to be the debug port,The three sentences commented out above must be added,打开AFIO,Remap pins multiplexed by peripherals,Release the debug port




//4、配置GPIO

	GPIO_InitTypeDef GPIO_InitStructure;
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //Select multiplexed push-pull output
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0;		//重映射之后 GPIO_Pin_15;
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
//2、配置时基单元

	TIM_InternalClockConfig(TIM2);//Select the clock for the time base unit,选择内部时钟,可以不写,Because the internal clock is selected by default after the timer is powered on


	TIM_TimeBaseInitTypeDef TIM_TimeBaseInitStructure;
	TIM_TimeBaseInitStructure.TIM_ClockDivision = TIM_CKD_DIV1;
	TIM_TimeBaseInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
	TIM_TimeBaseInitStructure.TIM_Period = 100 - 1;		//ARR=====固定住的话,周期就是100
	TIM_TimeBaseInitStructure.TIM_Prescaler = 720 - 1;		//PSC=====固定住的话,周期就是100
	TIM_TimeBaseInitStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM2, &TIM_TimeBaseInitStructure);

//3、配置输出比较单元

	TIM_OCInitTypeDef TIM_OCInitStructure;//初始化输出比较单元
	TIM_OCStructInit(&TIM_OCInitStructure); //给结构体赋初始值 It defines the initial value given by default,Prevent advanced timer errors
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //PWM1模式
	TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //输出比较极性 high 高级性 极性不翻转 有效电平为高电平
	TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
	TIM_OCInitStructure.TIM_Pulse = 0;		//CCR寄存器的值 How much is the percent duty cycle
	TIM_OC1Init(TIM2, &TIM_OCInitStructure);//PA0The port corresponds to the first output compare channelOC1
//CCR ARR PSC共同决定pwm的周期和占空比 *看公式

//5、运行控制

	TIM_Cmd(TIM2, ENABLE);
}

void PWM_SetCompare1(uint16_t Compare)
{
    
	TIM_SetCompare1(TIM2, Compare); //CCR为0,通过setcompare可以设置CCR的值,Change channels individually1的CCR的值
}

Function introduction for output comparison

These four functions are the configuration output comparison module,A function configures a unit

void TIM_OC1Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC2Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC3Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);
void TIM_OC4Init(TIM_TypeDef* TIMx, TIM_OCInitTypeDef* TIM_OCInitStruct);

Used to assign a default value to the output comparison structure

void TIM_OCStructInit(TIM_OCInitTypeDef* TIM_OCInitStruct);

//——————————————————————————————————————————————**********———————————————————————————————到这里,The configuration of the output comparison is basically complete————————————————————————



单独修改CCR寄存器值的函数————————————————————————————————————**********——————————————————Four functions used to change the duty cycle—————————————————————————

void TIM_SetCompare1(TIM_TypeDef* TIMx, uint16_t Compare1);
void TIM_SetCompare2(TIM_TypeDef* TIMx, uint16_t Compare2);
void TIM_SetCompare3(TIM_TypeDef* TIMx, uint16_t Compare3);

————————————————————————————————————————————————**********——————————

十、重映射（重映像）

使用AFIO复用功能引脚重映射
Remapping method and pin correspondence ,Select a remapping method 查看参考手册

gpio.c Select a remapping method

GPIO_PartialRemap1_TIM2 //部分重映射1
GPIO_PartialRemap2_TIM2//部分重映射2
GPIO_FullRemap_TIM2//完全重映射

GPIO_PinRemapConfig（）is the remapping function

—————————————————————————————————————————————————————————————————————————

Unlock the debug port parameter：

  *     @arg GPIO_Remap_SWJ_NoJTRST      : Full SWJ Enabled (JTAG-DP + SW-DP) but without JTRST//解除JTRST引脚的复用 PB4------>GPIO
  *     @arg GPIO_Remap_SWJ_JTAGDisable  : JTAG-DP Disabled and SW-DP Enabled//解除JTAGMultiplexing of debug ports PA15、PB3、PB4
  *     @arg GPIO_Remap_SWJ_Disable      : Full SWJ Disabled (JTAG-DP + SW-DP)//把SWD和JTAGAll debug ports are disabled

• 把SWD和JTAGAll debug ports are disabled,5All pins becomeGPIO,There is no debugging function anymore,之后st-linkCan't download the program,Only download using serial port,Download a new program without the debug port,This will bring the debug port back,This parameter cannot be used indiscriminately
  

十一、了解部分

1、Configure forced output mode

void TIM_ForcedOC1Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC2Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC3Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);
void TIM_ForcedOC4Config(TIM_TypeDef* TIMx, uint16_t TIM_ForcedAction);

2、配置CCRof the preload function of the registers,影子寄存器,The written value does not take effect immediately,而是在更新事件才会生效

void TIM_OC1PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC2PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC3PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);
void TIM_OC4PreloadConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPreload);

3、Configure fast-enabled

void TIM_OC1FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC2FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC3FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);
void TIM_OC4FastConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCFast);

4、This function is in the manual,Cleared on external eventsREF信号,那一节有介绍

void TIM_ClearOC1Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC2Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC3Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);
void TIM_ClearOC4Ref(TIM_TypeDef* TIMx, uint16_t TIM_OCClear);

5、Set the polarity of the output compare individually

void TIM_OC1PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC1NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);//这里带“N”It is the configuration of the complementary channel in the advanced timer
void TIM_OC2PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC2NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC3PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);
void TIM_OC3NPolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCNPolarity);
void TIM_OC4PolarityConfig(TIM_TypeDef* TIMx, uint16_t TIM_OCPolarity);//OC4There are no complementary channels

6、Modify the output enable parameters individually

void TIM_CCxCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCx);
void TIM_CCxNCmd(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_CCxN);

7、选择输出比较模式

void TIM_SelectOCxM(TIM_TypeDef* TIMx, uint16_t TIM_Channel, uint16_t TIM_OCMode);