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AB32VG1系列之PWM

发布于 2021-03-19 19:07:44 浏览：1092 订阅该版

[tocm]

# PWM

> 时间：2021年3月19日08:50:09
>
> 作者：JiangYangJie
>
> 项目地址：https://gitee.com/JiangYangJie/ab32-vg1_-study_-notes

## 1.硬件

`AB32VG1`一共有六组`PWM`发生器，因为官方给的手册不够全面，因此从代码中进行数量(`pwm_config.h`)及通道(`drv_pwm.c`)的分析

> `pwm_config.h` 分析pwm发生器

```c
#ifdef BSP_USING_T3_PWM   // timer3 的pwm发生器
#ifndef T3_PWM_CONFIG
#define T3_PWM_CONFIG                         \
    {                                       \
       .pwm_handle          = TIM3_BASE,    \
       .name                = "t3pwm",       \
       .channel             = 0             \
    }
#endif /* T3_PWM_CONFIG */
#endif /* BSP_USING_T3_PWM */

#ifdef BSP_USING_T4_PWM  // timer4 的pwm发生器
#ifndef T4_PWM_CONFIG
#define T4_PWM_CONFIG                         \
    {                                       \
       .pwm_handle          = TIM4_BASE,    \
       .name                = "t4pwm",       \
       .channel             = 0             \
    }
#endif /* T4_PWM_CONFIG */
#endif /* BSP_USING_T4_PWM */

#ifdef BSP_USING_T5_PWM   // timer5 的pwm发生器
#ifndef T5_PWM_CONFIG
#define T5_PWM_CONFIG                         \
    {                                       \
       .pwm_handle          = TIM5_BASE,    \
       .name                = "t5pwm",       \
       .channel             = 0             \
    }
#endif /* T5_PWM_CONFIG */
#endif /* BSP_USING_T5_PWM */

#ifdef BSP_USING_LPWM0   // pwm 特殊发生器0
#ifndef LPWM0_CONFIG
#define LPWM0_CONFIG                        \
    {                                       \
       .pwm_handle          = PWM_BASE,     \
       .name                = "lpwm0",      \
       .channel             = 0             \
    }
#endif /* LPWM0_CONFIG */
#endif /* BSP_USING_LPWM0 */

#ifdef BSP_USING_LPWM1   // pwm 特殊发生器1
#ifndef LPWM1_CONFIG
#define LPWM1_CONFIG                        \
    {                                       \
       .pwm_handle          = PWM_BASE,     \
       .name                = "lpwm1",      \
       .channel             = 0             \
    }
#endif /* LPWM1_CONFIG */
#endif /* BSP_USING_LPWM1 */

#ifdef BSP_USING_LPWM2  // pwm 特殊发生器2
#ifndef LPWM2_CONFIG
#define LPWM2_CONFIG                        \
    {                                       \
       .pwm_handle          = PWM_BASE,     \
       .name                = "lpwm2",      \
       .channel             = 0             \
    }
#endif /* LPWM2_CONFIG */
#endif /* BSP_USING_LPWM2 */

#ifdef BSP_USING_LPWM3  // pwm 特殊发生器3
#ifndef LPWM3_CONFIG
#define LPWM3_CONFIG                        \
    {                                       \
       .pwm_handle          = PWM_BASE,     \
       .name                = "lpwm3",      \
       .channel             = 0             \
    }
#endif /* LPWM3_CONFIG */
#endif /* BSP_USING_LPWM3 */
```

```c
static void pwm_get_channel(void)
{
#ifdef BSP_USING_T3_PWM0   // timer3 pwm 0通道  -》 PB0
    ab32_pwm_obj[T3_PWM_INDEX].channel |= 1 << 0;
#endif
#ifdef BSP_USING_T3_PWM1   // timer3 pwm 1通道
    ab32_pwm_obj[T3_PWM_INDEX].channel |= 1 << 1;
#endif
#ifdef BSP_USING_T3_PWM2   // timer3 pwm 2通道
    ab32_pwm_obj[T3_PWM_INDEX].channel |= 1 << 2;
#endif
#ifdef BSP_USING_T4_PWM0   // timer4 pwm 0通道 
    ab32_pwm_obj[T4_PWM_INDEX].channel |= 1 << 0;
#endif
#ifdef BSP_USING_T4_PWM1   // timer4 pwm 1通道 -》 PA6
    ab32_pwm_obj[T4_PWM_INDEX].channel |= 1 << 1;
#endif
#ifdef BSP_USING_T4_PWM2   // timer4 pwm 2通道
    ab32_pwm_obj[T4_PWM_INDEX].channel |= 1 << 2;
#endif
#ifdef BSP_USING_T5_PWM0   // timer5 pwm 0通道  -》 PE1
    ab32_pwm_obj[T5_PWM_INDEX].channel |= 1 << 0;
#endif 
#ifdef BSP_USING_T5_PWM1   // timer5 pwm 1通道
    ab32_pwm_obj[T5_PWM_INDEX].channel |= 1 << 1;
#endif
#ifdef BSP_USING_T5_PWM2   // timer5 pwm 2通道
    ab32_pwm_obj[T5_PWM_INDEX].channel |= 1 << 2;
#endif
#ifdef BSP_USING_LPWM0     // lpwm0 pwm 0通道 ——》 PE4(G1)   G1,G2.G3之间相互互斥
    ab32_pwm_obj[LPWM0_INDEX].channel |= 1 << 0;
#endif
#ifdef BSP_USING_LPWM1      // lpwm1 pwm 0通道， -》 PA1(G3)
    ab32_pwm_obj[LPWM1_INDEX].channel |= 1 << 0;
#endif
#ifdef BSP_USING_LPWM2       // lpwm2 pwm 0通道，-》PE0(G2)/PA2(G3)
    ab32_pwm_obj[LPWM2_INDEX].channel |= 1 << 0;
#endif
#ifdef BSP_USING_LPWM3       // lpwm3 pwm 0通道
    ab32_pwm_obj[LPWM3_INDEX].channel |= 1 << 0;
#endif
}
```
![image-20210319091507857.png](https://oss-club.rt-thread.org/uploads/20210319/e9c19bad69ae11f51b29b4161dc4c86a.png)
板载RGB的三个引脚，都可以做PWM输出引脚用。因此本次采用PE1进行PWM实验。

## 2.软件
![image-20210319091752392.png](https://oss-club.rt-thread.org/uploads/20210319/a1ed5af3b5a05a1809370fd8f510b5d4.png)

```c
#define PWM_DEV_NAME        "t5pwm"  /* PWM设备名称 这个命名与官方例程不一样，要注意！！！ */
#define PWM_DEV_CHANNEL     1       /* PWM通道 */
struct rt_device_pwm *pwm_dev;      /* PWM设备句柄 */
ALIGN(RT_ALIGN_SIZE)
static uint8_t PWM_Thread_Stack[1024];
static void PWM_Thread_Entry(void *para);
static struct rt_thread pwm_thread;
rt_uint32_t period, pulse;
void Pwm_Init(void){
    period = 1000;    /* 周期 */
    pulse = 0;          /* PWM脉冲宽度值(0 - 1000) */
    pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);
    RT_ASSERT(pwm_dev != RT_NULL);
    /* 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);
}

static void PWM_Thread_Entry(void *para){
    Pwm_Init();
    while(1){
        for (int var = 0; var < period; var += 100) {
            rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period, var);
            rt_thread_mdelay(1000);
        }
    }
}

int Pwm_Thread_Init(void){

rt_thread_init(&pwm_thread, "pwm_thread", PWM_Thread_Entry, RT_NULL,
            &PWM_Thread_Stack[0], sizeof(PWM_Thread_Stack), 10, 10);

rt_thread_startup(&pwm_thread);
    return 0;
}
INIT_APP_EXPORT(Pwm_Thread_Init);
```

本次实验可以看到板载RGB灯发出红光，且从亮到暗进行变换。

## 3.效果

[Bilibili](https://www.bilibili.com/video/BV1fv411b7Ai/)

## 参考

[《玩转中科蓝讯(AB32VG1)开发板》第2章 全彩LED实现魔幻色彩](https://club.rt-thread.org/ask/article/2611.html)