配置死区

1万 · 2018-7-24 19:15

用timer1 出一对占空比相等，相位差180的PWM

2万 · 2018-7-24 19:18

用中央对齐模式，一个通道模式用pwm1，一个用pwm2

2万 · 2018-7-24 19:19

STC没有反向PWM?
我们的都有哦，看看资料选择有多路PWM的MCU都有这个功能。

1万 · 2018-7-24 19:21

这不是反相的问题，用中心对称的 pwm 可以实现，设置占空比为互补值就是了

1万 · 2018-7-24 19:23

实在搞不了就直接上IO模拟的，那个波形太随意了。

1万 · 2018-7-24 19:25

个人更倾向于使用PWM1,PWM2的方式，因为Toggle（翻转）模式需要考虑Channel的初始状态
需要在Toggle开始前强制设定两个Channel的相位，曾经产品上就出现过这样的问题(相同的HEX，运行时产生不同的结果)
根据香主的提示写的一段能满足楼主要求的代码
/**
  软件: IAR 4.42 32K 限制版
  库: 2.0
  硬件: 万利 EKSTM3210B-LK1
  说明: 使用TIM3的Channel3和Channel4产生楼主所述波形
*/
#define Fsys          72000000ul //  system freq 72MHz
#define Fpwm          20000       //  PWM freq  20K
#define PWM_DUTY    20          //  PWM duty 20%
void  ConfigTimer(void)
{
  TIM_TimeBaseInitTypeDef  TIM_TimeBaseStructure;
  TIM_OCInitTypeDef  TIM_OCInitStructure;
  GPIO_InitTypeDef GPIO_InitStructure;

  RCC_APB1PeriphClockCmd(  RCC_APB1Periph_TIM3,ENABLE);
  RCC_APB2PeriphClockCmd(  RCC_APB2Periph_GPIOB,ENABLE);

  TIM_DeInit(TIM3);
  TIM_TimeBaseStructure.TIM_Prescaler = 0;
  TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_CenterAligned1;
  TIM_TimeBaseStructure.TIM_Period = (Fsys/2) / Fpwm;
  TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
  TIM_TimeBaseStructure.TIM_RepetitionCounter = 0;
  TIM_TimeBaseInit(TIM3,&TIM_TimeBaseStructure);

  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
  TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
  TIM_OCInitStructure.TIM_OutputNState = TIM_OutputState_Disable;
  TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
  TIM_OCInitStructure.TIM_OCNPolarity = TIM_OCNPolarity_Low;
  TIM_OCInitStructure.TIM_OCIdleState = TIM_OCIdleState_Reset;
  TIM_OCInitStructure.TIM_OCNIdleState = TIM_OCIdleState_Reset;
  TIM_OCInitStructure.TIM_Pulse = (((Fsys/2) / Fpwm) * PWM_DUTY) / 100;
  TIM_OC3Init(TIM3,&TIM_OCInitStructure);

  TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM2;
  TIM_OCInitStructure.TIM_Pulse = (((Fsys/2) / Fpwm) * (100-PWM_DUTY)) / 100;
  TIM_OC4Init(TIM3,&TIM_OCInitStructure);

  GPIO_InitStructure.GPIO_Pin =  GPIO_Pin_0 | GPIO_Pin_1;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
  GPIO_Init(GPIOB, &GPIO_InitStructure);

  TIM_CtrlPWMOutputs(TIM3, ENABLE);
  TIM_Cmd(TIM3,ENABLE);
}

无图无真相。图中CH3即 Timer3 Channel3(GPIOB.0), CH4即 Timer3 Channel4(GPIOB.1)

1万 · 2018-7-24 19:28

解决
TIM1_TimeBaseInit(0, TIM1_COUNTERMODE_CENTERALIGNED1, 399,0);

TIM1_OC1Init(TIM1_OCMODE_PWM1, TIM1_OUTPUTSTATE_ENABLE, TIM1_OUTPUTNSTATE_ENABLE,
            CCR1_Val, TIM1_OCPOLARITY_HIGH, TIM1_OCNPOLARITY_LOW, TIM1_OCIDLESTATE_SET,
            TIM1_OCNIDLESTATE_RESET);

TIM1_OC2Init(TIM1_OCMODE_PWM2, TIM1_OUTPUTSTATE_ENABLE, TIM1_OUTPUTNSTATE_ENABLE,
            CCR2_Val, TIM1_OCPOLARITY_HIGH, TIM1_OCNPOLARITY_LOW, TIM1_OCIDLESTATE_SET,
            TIM1_OCNIDLESTATE_RESET);