文章目录
1、高级定时器和通用定时器
高级定时器:TIM1、TIM8
Tips:黄色词条为高级定时器相对于通用定时器的功能。
通用定时器:TIM2~TIM5
基本定时器:TIM6、TIM7
Tips:独有触发DAC的同步电路。
2、配置产生PWM
计算公式为:溢出时间Tout(单位秒)=(arr+1)(psc+1)/Tclk
计算实例:20MS = (59999+1)*(23+1)/72000000
arr->系统自动装填数字;psc->预分频系数
使用F103C8系列单片机产生PWM
#include "Sys.h"
//公式为:溢出时间Tout(单位秒)=(arr+1)(psc+1)/Tclk
//20MS = (59999+1)*(23+1)/72000000
void ServoInit()//定时器1产生50HZ的PWM
{
GPIO_InitTypeDef GPIO;
TIM_OCInitTypeDef TIM_OC;
TIM_TimeBaseInitTypeDef TIM_Time;
//RCC_APB1PeriphClockCmd(RCC_APB2Periph_TIM1,ENABLE);
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_TIM1,ENABLE);
//IO配置
GPIO.GPIO_Pin = GPIO_Pin_11;
GPIO.GPIO_Speed = GPIO_Speed_50MHz;
GPIO.GPIO_Mode = GPIO_Mode_AF_PP;//复用推挽
GPIO_Init(GPIOA,&GPIO);
//PWM模式及通道设置
TIM_OC.TIM_OCMode = TIM_OCMode_PWM1;//CNT<CCR1为有效电平
TIM_OC.TIM_OCPolarity = TIM_OCPolarity_High;//有效电平:高电平
TIM_OC.TIM_OutputState = TIM_OutputState_Enable;//输出使能
TIM_OC4Init(TIM1,&TIM_OC);
TIM_OC4PreloadConfig(TIM1,TIM_OCPreload_Enable);
//PWM周期设置
TIM_Time.TIM_Period = 60000-1;//系统自动装填数字
TIM_Time.TIM_Prescaler = 24-1;//预分频系数
TIM_Time.TIM_CounterMode = TIM_CounterMode_Up;//向上计数溢出
TIM_Time.TIM_ClockDivision = TIM_CKD_DIV1;//时钟分频因子
TIM_Time.TIM_RepetitionCounter = 0;
TIM_TimeBaseInit(TIM1,&TIM_Time);
TIM_Cmd(TIM1,ENABLE);//定时器使能
TIM_CtrlPWMOutputs(TIM1, ENABLE);//pwm输出高级定时器特有
//舵机归中
TIM_SetCompare4(TIM1,4500);//舵机归中4500
}
void MotoInit(void)//定时器4产生1200HZ的PWM
{
GPIO_InitTypeDef GPIO;
TIM_OCInitTypeDef TIM_OC;
TIM_TimeBaseInitTypeDef TIM_Time;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB,ENABLE);
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4,ENABLE);
GPIO.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7|GPIO_Pin_8|GPIO_Pin_9;
GPIO.GPIO_Speed = GPIO_Speed_50MHz;
GPIO.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOB,&GPIO);
TIM_OC.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OC.TIM_OutputState = TIM_OutputState_Enable;
TIM_OC.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM4,&TIM_OC);
TIM_OC2Init(TIM4,&TIM_OC);
TIM_OC3Init(TIM4,&TIM_OC);
TIM_OC4Init(TIM4,&TIM_OC);
TIM_Time.TIM_Prescaler = 0;
TIM_Time.TIM_CounterMode = TIM_CounterMode_Up;
TIM_Time.TIM_Period = 60000-1;
TIM_Time.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseInit(TIM4,&TIM_Time);
TIM_Cmd(TIM4,ENABLE);
MotoControl(0,0);
}