g90舵机怎么一直在抖_新手入门调MG995舵机，发现把程序拷进32板后，舵机一直在抖...

void TIM1_PWM_Init(u16 arr,u16 psc)

{

GPIO_InitTypeDef GPIO_InitStructure;

TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;

TIM_OCInitTypeDef  TIM_OCInitStructure;

RCC_APB2PeriphClockCmd(RCC_APB2Periph_TIM1, ENABLE);//

RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);  //使能GPIO外设时钟使能

//设置该引脚为复用输出功能,输出TIM1 CH1的PWM脉冲波形

GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8; //TIM_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);

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  80K

TIM_TimeBaseStructure.TIM_Prescaler =psc; //设置用来作为TIMx时钟频率除数的预分频值  不分频

TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分割:TDTS = Tck_tim

TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;  //TIM向上计数模式

TIM_TimeBaseInit(TIM1, &TIM_TimeBaseStructure); //根据     TIM_TimeBaseInitStruct中指定的参数初始化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_High; //输出极性:TIM输出比较极性高

TIM_OC1Init(TIM1, &TIM_OCInitStructure);  //根据TIM_OCInitStruct中指定的参数初始化外设TIMx

TIM_CtrlPWMOutputs(TIM1,ENABLE);  //MOE 主输出使能

TIM_OC1PreloadConfig(TIM1, TIM_OCPreload_Enable);  //CH1预装载使能

TIM_ARRPreloadConfig(TIM1, ENABLE); //使能TIMx在ARR上的预装载寄存器

TIM_Cmd(TIM1, ENABLE);  //使能TIM1

}

int main(void)

{

SysTick_Init();            //延时函数初始化

TIM1_PWM_Init(199,7199);//(7200*200)/72000000=0.02=20ms

while(1)

{

TIM_SetCompare1(TIM1,185); //0度,1.5ms      占空比 %7.5

Delay_ms(1000);

TIM_SetCompare1(TIM1,190); //-45度,1ms      占空比 %5

Delay_ms(1000);

TIM_SetCompare1(TIM1,195); //-90度,0.5ms    占空比 %2.5

Delay_ms(1000);

TIM_SetCompare1(TIM1,185); //0度,1.5ms      占空比 %7.5

Delay_ms(1000);

TIM_SetCompare1(TIM1,180); //45度,2ms       占空比 %10

Delay_ms(1000);

TIM_SetCompare1(TIM1,175); //90度,2.5ms     占空比%12.5

Delay_ms(1000);

}

}

MG995舵机是新买回来的正品，代码已经检查过很多次，就是没发现问题在哪，求前辈赐教