本帖最后由 洪焯辉 于 2015-8-12 11:03 编辑
- #include "pwm.h"
- #include "led.h"
- //////////////////////////////////////////////////////////////////////////////////
- //PWM输出初始化
- //arr:自动重装值
- //psc:时钟预分频数
- void tiM1_PWM_Init(u16 arr,u16 psc)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
- TIM_OCInitTypeDef TIM_OCInitStructure;
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);//
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB|RCC_APB2Periph_GPIOC , ENABLE); //使能GPIO外设时钟使能
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6|GPIO_Pin_7; //
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOC, &GPIO_InitStructure);
- GPIO_SetBits(GPIOC, GPIO_Pin_6 | GPIO_Pin_7);
-
-
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_3|GPIO_Pin_4; //
- GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //复用推挽输出
- GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
- GPIO_Init(GPIOB, &GPIO_InitStructure);
- GPIO_SetBits(GPIOB, GPIO_Pin_3 | GPIO_Pin_4);
-
-
- //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_1; //TIM_CH4
- 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(TIM2, &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_OC2Init(TIM2, &TIM_OCInitStructure); //根据TIM_OCInitStruct中指定的参数初始化外设TIMx
- TIM_CtrlPWMOutputs(TIM2,ENABLE); //MOE 主输出使能
- TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable); //CH1预装载使能
-
- TIM_ARRPreloadConfig(TIM2, ENABLE); //使能TIMx在ARR上的预装载寄存器
-
- TIM_Cmd(TIM2, ENABLE); //使能TIM1
-
-
- }
- #include "led.h"
- #include "delay.h"
- #include "sys.h"
- #include "pwm.h"
- //ALIENTEK Mini STM32开发板范例代码8
- //PWM输出实验
- //技术支持:www.openedv.com
- //广州市星翼电子科技有限公司
- int main(void)
- {
- u16 led0pwmval=0;
- // u8 dir=1;
- delay_init(); //延时函数初始化
- LED_Init(); //初始化与LED连接的硬件接口
-
- TIM1_PWM_Init(899,0);//不分频。PWM频率=72000/(899+1)=80Khz
- while(1)
- {
- GPIO_SetBits(GPIOB, GPIO_Pin_3 | GPIO_Pin_4);
-
- GPIO_SetBits(GPIOC, GPIO_Pin_6 | GPIO_Pin_7);
- delay_ms(500);
- LED0=!LED0;
- led0pwmval=300;
- TIM_SetCompare2(TIM2,led0pwmval);
- }
- }
复制代码要使PB3 PB4 PC6 PC7输出高电平,但是只有PB3和PB4可以输出,不知道哪里出问题了,希望大家指点错误,谢谢!
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