GPIO是一種具有輸入和輸出功能的數(shù)字引腳,簡(jiǎn)稱(chēng)IO口。

IO口一般具有以下幾個(gè)功能模式:

1. 輸入上拉:內(nèi)部具有弱上拉，也就是高電平輸入模式。
2. 輸入下拉:內(nèi)部具有弱下拉，也就是低電平輸入模式。
3. 輸入:只具有讀取io口電平功能，同時(shí)引腳懸空，容易被外部影響而改變電平狀態(tài)。
4. 模擬輸入:輸入功能從數(shù)字變?yōu)槟M。
5. 輸出:IO口具有輸出功能，高低電平的輸出。
6. 推挽輸出:IO口利用功率管進(jìn)行驅(qū)動(dòng)、
7. 開(kāi)漏輸出:IO口的低電平具有輸出功能，而高電平則變?yōu)閼铱眨簿褪歉綦x。
8. 復(fù)用開(kāi)漏輸出:將IO口交由外設(shè)處理開(kāi)漏輸出。
9. 復(fù)用推挽輸出:將IO口交由外設(shè)處理推挽輸出。

我們基于上一個(gè)項(xiàng)目所使用的demo繼續(xù)。

我們開(kāi)始初始化定時(shí)器吧!

#define HWTIMER_DEV_NAME   "time2"     /* 定時(shí)器名稱(chēng) */

/* 定時(shí)器超時(shí)回調(diào)函數(shù) */
static rt_err_t timeout_cb(rt_device_t dev, rt_size_t size)
{
    rt_kprintf("this is hwtimer timeout callback fucntion!n");
    rt_kprintf("tick is :%d !n", rt_tick_get());

    return 0;
}

static int hwtimer_sample(void)
{
    rt_err_t ret = RT_EOK;
    rt_hwtimerval_t timeout_s;      /* 定時(shí)器超時(shí)值 */
    rt_device_t hw_dev = RT_NULL;   /* 定時(shí)器設(shè)備句柄 */
    rt_hwtimer_mode_t mode;         /* 定時(shí)器模式 */

    /* 查找定時(shí)器設(shè)備 */
    hw_dev = rt_device_find(HWTIMER_DEV_NAME);
    if (hw_dev == RT_NULL)
    {
        rt_kprintf("hwtimer sample run failed! can't find %s device!n", HWTIMER_DEV_NAME);
        return RT_ERROR;
    }

    /* 以讀寫(xiě)方式打開(kāi)設(shè)備 */
    ret = rt_device_open(hw_dev, RT_DEVICE_OFLAG_RDWR);
    if (ret != RT_EOK)
    {
        rt_kprintf("open %s device failed!n", HWTIMER_DEV_NAME);
        return ret;
    }

    /* 設(shè)置超時(shí)回調(diào)函數(shù) */
    rt_device_set_rx_indicate(hw_dev, timeout_cb);

    /* 設(shè)置模式為周期性定時(shí)器 */
    mode = HWTIMER_MODE_PERIOD;
    ret = rt_device_control(hw_dev, HWTIMER_CTRL_MODE_SET, &mode);
    if (ret != RT_EOK)
    {
        rt_kprintf("set mode failed! ret is :%dn", ret);
        return ret;
    }

    /* 設(shè)置定時(shí)器超時(shí)值為5s并啟動(dòng)定時(shí)器 */
    timeout_s.sec = 0;      /* 秒 */
    timeout_s.usec = 1000;     /* 微秒 */

    if (rt_device_write(hw_dev, 0, &timeout_s, sizeof(timeout_s)) != sizeof(timeout_s))
    {
        rt_kprintf("set timeout value failedn");
        return RT_ERROR;
    }

    /* 延時(shí)3500ms */
    rt_thread_mdelay(3500);

    /* 讀取定時(shí)器當(dāng)前值 */
    rt_device_read(hw_dev, 0, &timeout_s, sizeof(timeout_s));
    rt_kprintf("Read: Sec = %d, Usec = %dn", timeout_s.sec, timeout_s.usec);

    return ret;
}				

我們進(jìn)入rtthead進(jìn)行組件設(shè)置,打開(kāi)time的組件和硬件使能即可！

我們修改定時(shí)器回調(diào)函數(shù)的內(nèi)容!

/* 定時(shí)器超時(shí)回調(diào)函數(shù) */
static rt_err_t timeout_cb(rt_device_t dev, rt_size_t size)
{
    //rt_kprintf("this is hwtimer timeout callback fucntion!n");
    //rt_kprintf("tick is :%d !n", rt_tick_get());
    ledDelay++;
    if(ledDelay>=ledDelayVal){
        ledDelay=0;
        ledStatus=~ledStatus;
    }
    buttonShadeTime++;
    if(buttonShadeTime>=buttonShadeTimeVal){
        buttonShadeTime=0;
        buttonShadeFlag=1;
    }
    mnbn1S++;
    if(mnbn1S>=mnbn1SVal){
        mnbn1S=0;
        rt_kprintf("button is :%d !n", rt_pin_read(Button_PIN));
    }
    return 0;
}

我們添加方法:

#define LED_PIN     GET_PIN(0, 0)
#define Button_PIN  GET_PIN(5,0)
#define ledDelayVal 500
unsigned char buttonDownFlag=0;
unsigned char ledDownFlag=0;
unsigned short ledDelay=0;
unsigned char ledStatus=0;
#define buttonShadeTimeVal 10
unsigned char buttonShadeTime=0;
#define buttonShadeCountVal 5
unsigned char buttonShadeCount=0;
unsigned char buttonShadeFlag=0,buttonFinshFlag=0;
unsigned char buttonDownLast=0;
#define mnbn1SVal 1000
unsigned short mnbn1S=0;
#define HWTIMER_DEV_NAME   "time2"     /* 定時(shí)器名稱(chēng) */
void ButtonShadeHandler(void){
    if(!buttonShadeFlag){
           return;
    }
    buttonShadeFlag=0;
    if((!rt_pin_read(Button_PIN))==buttonDownLast){
        buttonShadeCount++;
        if(buttonShadeCount>=buttonShadeCountVal){
            buttonShadeCount=0;
            buttonFinshFlag=1;
        }
    }else{
        buttonDownLast=!rt_pin_read(Button_PIN);
        buttonShadeCount=0;
    }
}
void ButtonHandler(void){
    if(!buttonFinshFlag){
           return;
    }
    buttonFinshFlag=0;
    if(!buttonDownLast){
      if(!buttonDownFlag){
       buttonDownFlag=1;
       ledDownFlag=~ledDownFlag;
      }
   }else{
      buttonDownFlag=0;
   }
}

我們修改main方法為:

int main(void)
{
    rt_pin_mode(LED_PIN, PIN_MODE_OUTPUT);
    rt_pin_mode(Button_PIN, PIN_MODE_INPUT_PULLUP);
    hwtimer_sample();
    while(1)
    {
        ButtonShadeHandler();
        ButtonHandler();
        if(!ledDownFlag){
            if(!ledStatus){
                rt_pin_write(LED_PIN, PIN_HIGH);
            }else{
                rt_pin_write(LED_PIN, PIN_LOW);
            }
        }else{
            rt_pin_write(LED_PIN, PIN_HIGH);
        }

    }
}

運(yùn)行效果:

點(diǎn)擊P5.0接口的button來(lái)實(shí)現(xiàn)主板的燈控制！按一下開(kāi)始閃爍，按一下關(guān)。