stm32多路PWM
时间:10-02
整理:3721RD
点击:
- 在做多通道PWM输出的时候还是要注意很多问题的,由于我用的是STM32C8T6,定时器有4个,分别是一个高级控制定时器TIM1,和三个通用定时器。
- TIMER输出PWM实现步骤:
- 1. 设置RCC时钟;
- 2. 设置GPIO时钟;
- 3. 设置TIMx定时器的相关寄存器;
- 4. 设置TIMx定时器的PWM相关寄存器。
- 附上源码(以TIM2为例:两个通道)
- /*
- * 函数名:TIM2_GPIO_Config
- * 描述 :配置TIM3复用输出PWM时用到的I/O
- * 输入 :无
- * 输出 :无
- * 调用 :内部调用
- */
- static void TIM2_GPIO_Config(void)
- {
- GPIO_InitTypeDef GPIO_InitStructure;
- /* TIM3 clock enable */
- //PCLK1经过2倍频后作为TIM3的时钟源等于36MHz
- RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
- /* GPIOA and GPIOB clock enable */
- RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA , ENABLE);
- /*GPIOA Configuration: TIM3 channel 1 and 2 as alternate function push-pull */
- GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1;
- 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);
- }
- static void TIM2_Mode_Config(void)
- {
- TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
- TIM_OCInitTypeDef TIM_OCInitStructure;
- /* PWM信号电平跳变值 */
- u16 CCR1_Val = 251;
- u16 CCR2_Val = 251;
- /* -----------------------------------------------------------------------
- TIM2 Configuration: generate 4 PWM signals with 4 different duty cycles:
- TIM2CLK = 36 MHz, Prescaler = 0x0, TIM3 counter clock = 36 MHz
- TIM2 ARR Register = 999 => TIM3 Frequency = TIM3 counter clock/(ARR + 1)
- TIM2 Frequency = 36 KHz.
- TIM2 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
- TIM2 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 37.5%
- TIM2 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 25%
- TIM2 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 12.5%
- ----------------------------------------------------------------------- */
- /* Time base configuration */
- TIM_TimeBaseStructure.TIM_Period = 9999; //当定时器从0计数到999,即为1000次,为一个定时周期
- TIM_TimeBaseStructure.TIM_Prescaler = 144; //设置预分频:不预分频,即为36MHz
- TIM_TimeBaseStructure.TIM_ClockDivision = 0; //设置时钟分频系数:不分频
- TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up; //向上计数模式
- TIM_TimeBaseInit(TIM2, &TIM_TimeBaseStructure);
- /* PWM1 Mode configuration: Channel1 */
- TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1; //配置为PWM模式1
-
-
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR1_Val; //设置跳变值,当计数器计数到这个值时,电平发生跳变
- TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High; //当定时器计数值小于CCR1_Val时为高电平
- TIM_OC1Init(TIM2, &TIM_OCInitStructure); //使能通道1
- TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);
- /* PWM1 Mode configuration: Channel2 */
- TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
- TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //设置通道2的电平跳变值,输出另外一个占空比的PWM
- TIM_OC2Init(TIM2, &TIM_OCInitStructure); //使能通道2
- TIM_OC2PreloadConfig(TIM2, TIM_OCPreload_Enable);
- TIM_ARRPreloadConfig(TIM2, ENABLE); // 使能TIM2重载寄存器ARR
- /* TIM2 enable counter */
- TIM_Cmd(TIM2, ENABLE); //使能定时器2
- }
- /*
- * 函数名:TIM2_Mode_Config
- * 描述 :TIM2 输出PWM信号初始化,只要调用这个函数
- * TIM2的两个通道就会有PWM信号输出
- * 输入 :无
- * 输出 :无
- * 调用 :外部调用
- */
- void TIM2_PWM_Init(void)
- {
- TIM2_GPIO_Config();
- TIM2_Mode_Config();
- }
- 在配置其他两个通用定时器时,配置几乎是相同的,但是在配置TIM1的时候需要加这个函数以使能TIM1的PWM输出
- TIM_CtrlPWMOutputs(TIM1, ENABLE);
是的。同样的问题我在STM32F103RB上也遇到过,因为T1高级定时器。
1./* TIM3 clock enable */小编你用的是TIM2吧
2.TIM_TimeBaseStructure.TIM_Prescaler = 144; //设置预分频:不预分频,即为36MHz
这里你分频了,不是36MHz
有点不是很清楚,怎么使能通道1和2的?
TIM_OC1Init(TIM2, &TIM_OCInitStructure); //使能通道1
TIM_OC1PreloadConfig(TIM2, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val; //设置通道2的电平跳变值,输出另外一个占空比的PWM
TIM_OC2Init(TIM2, &TIM_OCInitStructure); //使能通道2
虽然看不太懂,学习中。
小编辛苦了,十分感谢!
这个程序有点乱
这个程序有点乱
这个程序有点乱