rtthread pwm设备控制led小灯亮度

迷南。 2022-08-31 13:19 259阅读 0赞

本文所讲内容的开发坏境基于keil5,rt-thread-4.0.3,env,STM32CubeMX等，硬件为德飞莱尼莫m3s开发板。开发环境搭建及安装请自行百度。内容简单粗暴，不要太计较，主要是实现了功能。

本文不讲理论知识，rttheard PWM设备驱动相关知识请移步官网[https://www.rt-thread.org/document/site/\#/rt-thread-version/rt-thread-standard/programming-manual/device/pwm/pwm][https_www.rt-thread.org_document_site_rt-thread-version_rt-thread-standard_programming-manual_device_pwm_pwm]

本文也不讲rtthread移植相关及env环境搭建，要想了解相关知识请移步官网[https://www.rt-thread.org/document/site/\#/development-tools/env/env][https_www.rt-thread.org_document_site_development-tools_env_env]

德飞莱尼莫m3s开发板采用STM32F103ZET6作为主控芯片，共有两个红色用户功能led灯，如下图：

![20210725212025706.png][]

本文选用led3 作为被控led灯，由图可知要想控制led3的亮度，就是控制PB5引脚的低电平持续时间，持续时间越长越亮，越短越暗。

查询STM32F103ZET6相关手册可知PB5对应TIM3\_CH2通道，所以我们就是要配置此引脚的PWM功能。方法如下：

1.通过env配置相关功能，进入工程目录下，rt-thread-4.0.3\\bsp\\stm32\\stm32f103-dofly-M3S，右击鼠标，弹出如下画面

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70][]

选择ConEmu Here后弹出如下所示画面

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 1][]

输入menuconfig后按回车键打开配置画面，如下：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 2][]

按键盘上下箭头选择第二项，RT-Thread Components --->，如下图

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 3][]

按回车进入，进入后按键盘上下箭头选择Device Drivers --->，如下图

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 4][]

按回车进入，进入后按键盘上下箭头选择\[ \] Using hardware timer device drivers，如下图

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 5][]

按下Y键使能此项配置，选项前面的方挂号内会多出\*,使能后如下图所示

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 6][]

继续往下找到 \[ \] Using PWM device drivers选项，并使能它，方法如上。如下图：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 7][]

使能之前需要修改一下Kconfig配置文件，此文件在rt-thread-4.0.3\\components\\drivers目录下，修改内容如下：

config RT_USING_PWM
        bool "Using PWM device drivers"
        default n
        if RT_USING_PWM
            config BSP_USING_PWM1
            bool "Using TIM1_PWM"
            default n
    
            if BSP_USING_PWM1
                config BSP_USING_PWM1_CH1
                bool "Using TIM1 PWM channel1"
                default n
    
                config BSP_USING_PWM1_CH2
                bool "Using TIM1 PWM channel1"
                default n
    
                config BSP_USING_PWM1_CH3
                bool "Using TIM1 PWM channel1"
                default n
    
                config BSP_USING_PWM1_CH4
                bool "Using TIM1 PWM channel1"
                default n
            endif
    
            config BSP_USING_PWM2
            bool "Using TIM2_PWM"
            default n
            
            if BSP_USING_PWM2
                config BSP_USING_PWM2_CH1
                bool "Using TIM2 PWM channel1"
                default n
    
                config BSP_USING_PWM2_CH2
                bool "Using TIM2 PWM channel2"
                default n
    
                config BSP_USING_PWM2_CH3
                bool "Using TIM2 PWM channel3"
                default n
    
                config BSP_USING_PWM2_CH4
                bool "Using TIM2 PWM channel4"
                default n
            endif
    
            config BSP_USING_PWM3
            bool "Using TIM3_PWM"
            default n
            
            if BSP_USING_PWM3
                config BSP_USING_PWM3_CH1
                bool "Using TIM3 PWM channel1"
                default n
    
                config BSP_USING_PWM3_CH2
                bool "Using TIM3 PWM channel2"
                default n
    
                config BSP_USING_PWM3_CH3
                bool "Using TIM3 PWM channel3"
                default n
    
                config BSP_USING_PWM3_CH4
                bool "Using TIM3 PWM channel4"
                default n
            endif
    
            config BSP_USING_PWM4
            bool "Using TIM4_PWM"
            default n
            
            if BSP_USING_PWM4
                config BSP_USING_PWM4_CH1
                bool "Using TIM4 PWM channel1"
                default n
    
                config BSP_USING_PWM4_CH2
                bool "Using TIM4 PWM channel2"
                default n
    
                config BSP_USING_PWM4_CH3
                bool "Using TIM4 PWM channel3"
                default n
    
                config BSP_USING_PWM4_CH4
                bool "Using TIM4 PWM channel4"
                default n
            endif
    
            config BSP_USING_PWM5
            bool "Using TIM5_PWM"
            default n
            
            if BSP_USING_PWM5
                config BSP_USING_PWM5_CH1
                bool "Using TIM5 PWM channel1"
                default n
    
                config BSP_USING_PWM5_CH2
                bool "Using TIM5 PWM channel2"
                default n
    
                config BSP_USING_PWM5_CH3
                bool "Using TIM5 PWM channel3"
                default n
    
                config BSP_USING_PWM5_CH4
                bool "Using TIM5 PWM channel4"
                default n
            endif
        endif

该段修改的内容具体是啥意思这里不作讲解，想了解的可以百度搜索相关资料研究。这段代码主要用来实现PWM功能的配置。使能后如下图所示：

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 8][]

从图中可以看出选择了 TIM3的PWM\_CH2功能。配置好后连续按ESC键退至如下所示画面

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ3NTQ4NDE_size_16_color_FFFFFF_t_70 9][]

按下回车键退出配置画面。

输入scons --target=mdk5按回车键重新生成keil5工程。

打开工程，在工程中stm32f1xx\_hal\_msp.c最下方添加如下代码：

void HAL_TIM_PWM_MspInit(TIM_HandleTypeDef* tim_pwmHandle)
    {
    
      if(tim_pwmHandle->Instance==TIM3)
      {
      /* USER CODE BEGIN TIM3_MspInit 0 */
    
      /* USER CODE END TIM3_MspInit 0 */
        /* TIM3 clock enable */
        __HAL_RCC_TIM3_CLK_ENABLE();
      /* USER CODE BEGIN TIM3_MspInit 1 */
    
      /* USER CODE END TIM3_MspInit 1 */
      }
    }
    void HAL_TIM_MspPostInit(TIM_HandleTypeDef* timHandle)
    {
    
      GPIO_InitTypeDef GPIO_InitStruct = {0};
      if(timHandle->Instance==TIM3)
      {
      /* USER CODE BEGIN TIM3_MspPostInit 0 */
    
      /* USER CODE END TIM3_MspPostInit 0 */
    
        __HAL_RCC_GPIOB_CLK_ENABLE();
        /**TIM3 GPIO Configuration
        PB5     ------> TIM3_CH2
        */
        GPIO_InitStruct.Pin = GPIO_PIN_5;
        GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
        GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
        HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
    
        __HAL_AFIO_REMAP_TIM3_PARTIAL();
    
      /* USER CODE BEGIN TIM3_MspPostInit 1 */
    
      /* USER CODE END TIM3_MspPostInit 1 */
      }
    
    }
    
    void HAL_TIM_PWM_MspDeInit(TIM_HandleTypeDef* tim_pwmHandle)
    {
    
      if(tim_pwmHandle->Instance==TIM3)
      {
      /* USER CODE BEGIN TIM3_MspDeInit 0 */
    
      /* USER CODE END TIM3_MspDeInit 0 */
        /* Peripheral clock disable */
        __HAL_RCC_TIM3_CLK_DISABLE();
      /* USER CODE BEGIN TIM3_MspDeInit 1 */
    
      /* USER CODE END TIM3_MspDeInit 1 */
      }
    }

该段代码主要用于初始化PB5引脚的PWM硬件功能，此段代码可以通过STM32CubeMX生成，生成方法自己百度搜索解决。

编译工程测试设备驱动添加是否成功，如果编译无错表示添加成功，编译有误根据实际错误排查问题，如有疑问可以联系我一起帮忙解决。

在主程序中添加测试代码，如下：

int main(void)
    {    
            struct rt_device_pwm *pwm_dev;      /* PWM设备句柄 */
    		static rt_uint32_t period, pulse;
    		
    		#define PWM_DEV_NAME        "pwm3"  /* PWM设备名称 */
    		#define PWM_DEV_CHANNEL     2       /* PWM通道 */
    
    		period = 500000;    /* 周期为0.5ms，单位为纳秒ns */
    		pulse = 0;          /* PWM脉冲宽度值，单位为纳秒ns */
    		/* 查找设备 */
    		pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);
    		/* 设置PWM周期和脉冲宽度 */
    		rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
    		/* 使能设备 */
    		rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);
    //		/* 关闭设备通道 */
    //		rt_pwm_disable(pwm_dev,PWM_DEV_CHANNEL);
    		
    
    		
    	while (count++)
        {
        	pulse = pulse + 2000;
    		if(pulse >= period) pulse = 0;
    		rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
            rt_thread_mdelay(10);
        }
        return RT_EOK;
    }

编译后下载至开发板中观察led3调节亮度效果，如下：

rtthread pwm调节led亮度

[https://v.qq.com/x/page/n3263z7js0k.html][https_v.qq.com_x_page_n3263z7js0k.html]

[https_www.rt-thread.org_document_site_rt-thread-version_rt-thread-standard_programming-manual_device_pwm_pwm]: https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/device/pwm/pwm
[https_www.rt-thread.org_document_site_development-tools_env_env]: https://www.rt-thread.org/document/site/#/development-tools/env/env
[20210725212025706.png]: /images/20220829/6142f86ed0b744e396331fa8e71f4f7e.png
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[https_v.qq.com_x_page_n3263z7js0k.html]: https://v.qq.com/x/page/n3263z7js0k.html