stm32_template/module_Template/SG90/SG90.c

#include "main.h"

static void SG90_TIM3_Init(u16 arr,u16 psc);
static void SG90_Angle(float angle);

SG90ClassStruct SG90Class = {
	SG90_TIM3_Init,
	SG90_Angle
};

// PWM初始化 1000-1,1440-1
static void SG90_TIM3_Init(u16 arr,u16 psc)
{
  GPIO_InitTypeDef GPIO_InitStructure;
	TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
	TIM_OCInitTypeDef  TIM_OCInitStructure;

	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE);  //使能GPIO外设时钟使能
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
	RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); //时钟使能
	
	//设置该引脚为复用输出功能,输出TIM3 CH1的PWM脉冲波形
	GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6; //TIM3_CH1
	GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;  //复用推挽输出
	GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
	GPIO_Init(GPIOA, &GPIO_InitStructure);
	
	//定时器TIM3初始化
	TIM_TimeBaseStructure.TIM_Period = arr; //设置在下一个更新事件装入活动的自动重装载寄存器周期的值	
	TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值
	TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1; //设置时钟分割:TDTS = Tck_tim
	TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式
	TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
	TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure); //根据指定的参数初始化TIMx的时间基数单位
 
	TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2; //选择定时器模式:TIM脉冲宽度调制模式2
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable; //比较输出使能
  TIM_OCInitStructure.TIM_Pulse = 0; //设置待装入捕获比较寄存器的脉冲值
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_Low; //输出极性:TIM输出比较极性高
  TIM_OC1Init(TIM3, &TIM_OCInitStructure);  //根据TIM_OCInitStruct中指定的参数初始化外设TIMx
	
  TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);  	//CH1预装载使能    
  TIM_ARRPreloadConfig(TIM3, ENABLE); //使能TIMx在ARR上的预装载寄存器
  TIM_Cmd(TIM3, ENABLE);  //使能TIMx
	TIM_CtrlPWMOutputs(TIM3,ENABLE);  //MOE 主输出使能				 
}

static void SG90_Angle(float angle)
{
	angle = (uint16_t)(50.0 * angle / 9.0 + 250.0);
	TIM_SetCompare1(TIM3, angle);
}