# RA8P1 Titan Board 开发板 GPT 使用说明

**中文** | [**English**](./README_EN.md)

## 简介

在我们具体的应用场合中往往都离不开 timer 的使用，本例程主要介绍了如何在 Titan Board 上使用 GPT 设备。

## FSP配置说明

FSP 配置使能 GPT7 为 PWM 模式：

![image-20250730145155124](figures/image-20250730145155124.png)

并配置 Pins 使能 GPT7：

![image-20250730145234806](figures/image-20250730145234806.png)

### RT-Thread Settings配置

在配置中打开 PWM7 使能：

![image-20250730145310691](figures/image-20250730145310691.png)

### 示例工程说明

本例程的源码位于`/projects/Titan_basic_buzzer/src/buzzer.c`：

```c
#include <rtthread.h>
#include <rtdevice.h>

#define PWM_DEV_NAME        "pwm7"  /* PWM设备名称 */
#define PWM_DEV_CHANNEL     0       /* PWM通道 */

struct rt_device_pwm *pwm_dev;

typedef struct
{
    uint16_t freq;   // 频率Hz
    uint16_t duration; // 持续时间ms
} note_t;

note_t song[] =
{
    {262,400}, {294,400}, {330,400}, {262,400},  // 1 2 3 1
    {262,400}, {294,400}, {330,400}, {262,400},  // 1 2 3 1
    {330,400}, {349,400}, {392,800},             // 3 4 5
    {330,400}, {349,400}, {392,800},             // 3 4 5
    {392,200}, {440,200}, {392,200}, {349,200}, {330,400}, {262,400}, // 5 6 5 4 3 1
    {392,200}, {440,200}, {392,200}, {349,200}, {330,400}, {262,400}, // 5 6 5 4 3 1
    {262,400}, {196,400}, {262,400}, {0,400},    // 1(低) 7(低) 1 高 休止
    {262,400}, {196,400}, {262,400}, {0,400},    // 1 7 1 休止
};

static int buzzer_test(void)
{
    pwm_dev = (struct rt_device_pwm *)rt_device_find(PWM_DEV_NAME);
    if (!pwm_dev)
    {
        rt_kprintf("Cannot find PWM device %s\n", PWM_DEV_NAME);
        return -1;
    }

    for (size_t i = 0; i < sizeof(song)/sizeof(song[0]); i++)
    {
        if (song[i].freq == 0)
        {
            rt_pwm_disable(pwm_dev, PWM_DEV_CHANNEL);
        }
        else
        {
            uint32_t period_ns = 1000000000 / song[i].freq;  // ns
            uint32_t pulse_ns  = period_ns / 2;              // 50%

            rt_pwm_set(pwm_dev, PWM_DEV_CHANNEL, period_ns, pulse_ns);
            rt_pwm_enable(pwm_dev, PWM_DEV_CHANNEL);
        }

        rt_thread_mdelay(song[i].duration);
    }

    rt_pwm_disable(pwm_dev, PWM_DEV_CHANNEL);
    return 0;
}
MSH_CMD_EXPORT(buzzer_test, Play song on buzzer);
```
##  编译&下载

* RT-Thread Studio：在 RT-Thread Studio 的包管理器中下载 Titan Board 资源包，然后创建新工程，执行编译。

编译完成后，将开发板的 Jlink 接口与 PC 机连接，然后将固件下载至开发板。

## 运行效果

在串口终端输入 buzzer_sample 查看具体效果，蜂鸣器会发出一段旋律。