RT-Thread-【英飞凌开发板模块评测任务大挑战】-2-PWM外设使用RT-Thread问答社区

【英飞凌开发板模块评测任务大挑战】-2-PWM外设使用

发布于 2023-05-04 10:07:37 浏览：341 订阅该版

[tocm]

# 2.PWM驱动

代码仓库地址：https://gitee.com/chejia12/rtt_-cy8-c624-alqalqi

## 2.1进入工程目录，启动 Env 控制台

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/7fb1e572d0a06a6389afd4fc08868d8b.png.webp)

## 2.2pwm 驱动使能

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/584e3b7f1903f783acca9c2e5aab4329.png.webp)

## 2.3保存配置，自动生成mdk5的工程

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/27a5df69c4a9f9c82d7c23244bd92a33.png)

## 2.4测试驱动代码

### 驱动涉及的io口

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/1693d30d94a67f834e21ccc360ac8b59.png)

### 在menuconfig中配置生成的宏

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/8f03c0c0297c942fecdbf1e411db72e8.png.webp)
### KConfig

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/448bd812303f8124f7a36a18842b5fb6.png.webp)
## 2.5测试代码

```c
//-----------------------------pwm测试代码 ---------------开始------------------
#define PWM_DEV_NAME "pwm0"
#define PWM_DEV_CHANNEL 0

struct rt_device_pwm *pwm_dev;

static int pwm_sample(int argc, char *argv[])
{
    rt_uint32_t period, pulse, dir;

period = 1 * 1000 * 1000;
    dir = 1;
    pulse = 0;

pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);

if (pwm_dev == RT_NULL)
    {
        rt_kprintf("pwm sample run failed! can't find %s device!\n", PWM_DEV_NAME);
        return -RT_ERROR;
    }

rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
    rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);

rt_kprintf("Now PWM[%s] Channel[%d] Period[%d] Pulse[%d]\n", PWM_DEV_NAME, PWM_DEV_CHANNEL, period, pulse);

while (1)
    {
        rt_thread_mdelay(50);

if (dir)
        {
            pulse += 100000;
        }
        else
        {
            pulse -= 100000;
        }

if (pulse >= period)
        {
            dir = 0;
        }

if (0 == pulse)
        {
            dir = 1;
        }

rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, pulse);
    }
}
//导出函数到命令行
MSH_CMD_EXPORT(pwm_sample, <pwm0> channel7 sample);
//-----------------------------pwm测试代码 ---------------结束------------------
```

## 2.6 pwm驱动框架学习

[RTT的I/O设备模型 ](https://www.rt-thread.org/document/site/#/rt-thread-version/rt-thread-standard/programming-manual/device/device)

![screenshot_image.png](https://oss-club.rt-thread.org/uploads/20230504/fbeea3f1bcf16a2867080708094716d9.png.webp)

1. 实现pwm控制函数

在控制函数内部根据命令的类型，编写对应的外设控制函数

>   rt_err_t (*control)(struct rt_device_pwm *device, int cmd, void *arg);

2. 命令的类型有
```c
#define PWM_CMD_ENABLE      (RT_DEVICE_CTRL_BASE(PWM) + 0)
#define PWM_CMD_DISABLE     (RT_DEVICE_CTRL_BASE(PWM) + 1)
#define PWM_CMD_SET         (RT_DEVICE_CTRL_BASE(PWM) + 2)
#define PWM_CMD_GET         (RT_DEVICE_CTRL_BASE(PWM) + 3)
#define PWMN_CMD_ENABLE     (RT_DEVICE_CTRL_BASE(PWM) + 4)		//互补输出打开
#define PWMN_CMD_DISABLE    (RT_DEVICE_CTRL_BASE(PWM) + 5)
#define PWM_CMD_SET_PERIOD  (RT_DEVICE_CTRL_BASE(PWM) + 6)		//设置周期
#define PWM_CMD_SET_PULSE   (RT_DEVICE_CTRL_BASE(PWM) + 7)		//设置占空比
#define PWM_CMD_SET_DEAD_TIME  (RT_DEVICE_CTRL_BASE(PWM) + 8)	//设置死去时间
#define PWM_CMD_SET_PHASE   (RT_DEVICE_CTRL_BASE(PWM) + 9)
#define PWM_CMD_ENABLE_IRQ  (RT_DEVICE_CTRL_BASE(PWM) + 10)
#define PWM_CMD_DISABLE_IRQ  (RT_DEVICE_CTRL_BASE(PWM) + 11)
```
3. 实现各个控制函数

>/*
   >
   >       1. rt_pwm_enable pwm使能函数，打开pwm输出
   >          2. rt_pwm_disable 关闭pwm输出
   >             3. rt_pwm_set 设置pwm频率和占空比函数
   >             4. rt_pwm_set_period 设置pwm周期
   >             5. rt_pwm_set_pulse 设置占空比
   >             6. rt_pwm_set_dead_time 设置pwm死区时间
   >             7. rt_pwm_set_phase 设置pwm的输出相位
   >                */
   >
   >rt_err_t rt_pwm_enable(struct rt_device_pwm *device, int channel);
   >rt_err_t rt_pwm_disable(struct rt_device_pwm *device, int channel);
   >rt_err_t rt_pwm_set(struct rt_device_pwm *device, int channel, rt_uint32_t period, rt_uint32_t pulse);
   >rt_err_t rt_pwm_set_period(struct rt_device_pwm *device, int channel, rt_uint32_t period);
   >rt_err_t rt_pwm_set_pulse(struct rt_device_pwm *device, int channel, rt_uint32_t pulse);
   >rt_err_t rt_pwm_set_dead_time(struct rt_device_pwm *device, int channel, rt_uint32_t dead_time);
   >rt_err_t rt_pwm_set_phase(struct rt_device_pwm *device, int channel, rt_uint32_t phase);

4. 填充注册前的各个配置结构体的参数

>1. 通道
   >2. 频率
   >3. 占空比
   >4. 死区时间
   >5. 相位调整
   >6. 互补输出使能
   >
   >struct rt_pwm_configuration
   >{
   >    rt_uint32_t channel; /* 0 ~ n or 0 ~ -n, which depends on specific MCU requirements这取决于特定的MCU要求 */
   >    rt_uint32_t period;  /* unit:ns 1ns~4.29s:1Ghz~0.23h 频率 */
   >    rt_uint32_t pulse;   /* unit:ns (pulse<=period)占空比 */
   >    rt_uint32_t dead_time;  /* unit:ns 死区时间设置 */
   >    rt_uint32_t phase;  /*unit: degree, 0~360, which is the phase of pwm output,其为pwm输出的相位， */
   >    /*
   >
   >   * RT_TRUE  : 互补输出
   >      RT_FALSE : 正常输出.
   >         */
   >         rt_bool_t  complementary;
   >     };

5. 注册pwm驱动

> rt_err_t rt_device_pwm_register(
   >                         struct rt_device_pwm *device, 
   >                         const char *name, 
   >                         const struct rt_pwm_ops *ops, 
   >                         const void *user_data); ```