1. pin设备

#define LED_PIN	3

int led(void)
{
    rt_uint8_t count;

    rt_pin_mode(LED_PIN, PIN_MODE_OUTPUT);  
    
    for(count = 0 ; count < 10 ;count++)
    {       
        rt_pin_write(LED_PIN, PIN_HIGH);
        rt_kprintf("led on, count : %d %d\r\n", count, rt_pin_read(LED_PIN));
        rt_thread_mdelay(500);
        
        rt_pin_write(LED_PIN, PIN_LOW);
        rt_kprintf("led off %d\r\n", rt_pin_read(LED_PIN));
        rt_thread_mdelay(500);
    }
    return 0;
}
MSH_CMD_EXPORT(led, RT-Thread first led sample);

2. 普通I/O设备

#define LED_PIN	3

int led(void)
{
    rt_uint8_t count;
    rt_device_t pin_dev;
    struct rt_device_pin_mode arg;
    struct rt_device_pin_status status;
    
    pin_dev = rt_device_find("pin");
    
    arg.pin = LED_PIN;
    arg.mode = PIN_MODE_OUTPUT;
    rt_device_control(pin_dev, RT_NULL, &arg);
    
    rt_device_open(pin_dev, 0);
    
    for(count = 0 ; count < 10 ;count++)
    {
        status.pin = LED_PIN;
        status.status = PIN_HIGH;
        rt_device_write(pin_dev, 0, &status, sizeof(&status));
        
        rt_kprintf("led on, count : %d\r\n", count);
        rt_thread_mdelay(500);
        
        status.pin = LED_PIN;
        status.status = PIN_LOW;
        rt_device_write(pin_dev, 0, &status, sizeof(&status));
        
        rt_kprintf("led off\r\n");
        rt_thread_mdelay(500);
    }
    return 0;
}
MSH_CMD_EXPORT(led, RT-Thread first led sample);