unit8_t 和 uint8_t?

```C

unit8_t btn1_id = 0;
struct Button btn1;

uint8_t read_button_GPIO(uint8_t button_id)
{
	// you can share the GPIO read function with multiple Buttons
	switch(button_id)
	{
		case btn1_id:
			return HAL_GPIO_ReadPin(B1_GPIO_Port, B1_Pin);
		default:
			return 0;
	}
}
```
哈？
