讓板載 三個(gè)用戶按鍵，通過掃描按鍵，打印按鍵值。

2. 開發(fā)板硬件平臺

按鍵硬件電路，可知，使用 按鍵要使用

PF1 —— S2

PF0 —— S3

PAS —— S4

3. 軟件編寫

在 application 目錄下，新建 key.c 和 key.h

//key.c
/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2021-11-06     Administrator       the first version
 */
#include "key.h"
#include 
#include "board.h"

struct key_s
{
    uint8_t k0;
    uint8_t k1;
    uint8_t k2;
};
struct key_s button;

//PF0   PF1     PA2
static int key_init(void)
{
    button.k0 = rt_pin_get("PF.0");
    button.k1 = rt_pin_get("PF.1");

    rt_pin_mode(button.k0, PIN_MODE_INPUT_PULLUP);
    rt_pin_mode(button.k1, PIN_MODE_INPUT_PULLUP);

    rt_kprintf("key init\n");
    return 0;
}

#define KEY0_PRES 1
#define KEY1_PRES 2

static uint8_t btn_scan(uint8_t mode)
{
    static uint8_t key_up = 1;

    if(mode)
        key_up = 1;

    if(key_up && ((rt_pin_read(button.k0) == PIN_LOW) || (rt_pin_read(button.k1) == PIN_LOW)))
    {
        rt_thread_mdelay(10);
        key_up = 0;
        if(rt_pin_read(button.k0) == PIN_LOW)
            return KEY0_PRES;
        else if(rt_pin_read(button.k1) == PIN_LOW)
            return KEY1_PRES;
    }else if((rt_pin_read(button.k0) == PIN_HIGH) && (rt_pin_read(button.k1) == PIN_HIGH))
        key_up = 1;

    return 0;
}

static void btn_thread_entry(void* p)
{
    uint8_t byn_value = 0;

    while(1)
    {
        byn_value = btn_scan(0);
        switch(byn_value)
        {
            case KEY0_PRES:
                rt_kprintf("key0 pushed\n");
                break;
            case KEY1_PRES:
                rt_kprintf("key1 pushed\n");
                break;
            default:
                break;
        }
        rt_thread_mdelay(100);
    }
}

static int Thread_btn(void)
{
    rt_thread_t thread = RT_NULL;

    key_init();
    thread = rt_thread_create("button", btn_thread_entry, RT_NULL, 512, 11, 10);
    if(thread == RT_NULL)
    {
        rt_kprintf("Thread_btn Init ERROR");
        return RT_ERROR;
    }
    rt_thread_startup(thread);
}

INIT_APP_EXPORT(Thread_btn);


//key.h
/*
 * Copyright (c) 2006-2021, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2021-11-06     Administrator       the first version
 */
#ifndef APPLICATIONS_KEY_H_
#define APPLICATIONS_KEY_H_


#endif /* APPLICATIONS_KEY_H_ */

修改main.c

/*
 * Copyright (c) 2020-2021, Bluetrum Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2020/12/10     greedyhao    The first version
 */

/**
 * Notice!
 * All functions or data that are called during an interrupt need to be in RAM.
 * You can do it the way exception_isr() does.
 */

#include 
#include "board.h"

int main(void)
{
    rt_kprintf("Hello, world\n");

    while (1)
    {
        rt_thread_mdelay(500);
        rt_thread_mdelay(500);
    }
}

4. 程序編譯下載

編譯程序，點(diǎn)擊小錘子即可。

下載程序

打開我們下載的Downloader軟件，雙擊Downloader.exe

配置連接串口，千萬不要搞錯(cuò)串口號哦。

選擇工程目錄下的\Debug\rtthread.dcf，這里我的完整目錄是

D:\RT-ThreadStudio\workspace\ab32vg1_demo\Debug\rtthread.dcf

點(diǎn)擊開始即可下載成功

5. 實(shí)驗(yàn)現(xiàn)象：

download 串口打印 msh 控制臺信息。

按鍵觸發(fā)打印，不支持連按。

6. 總結(jié)

目前是通過引腳輪詢讀取來實(shí)現(xiàn)按鍵掃描，后面可以試試IO中斷的方式實(shí)現(xiàn)，哈哈。

編輯：fqj