1、 The meaning of the engineering code area

I believe many beginners HAL library , use CubeMx After the generated project , There are many annotation codes , You don't understand what I mean? , I don't know why the code is written there . Today we will talk about ~

2、 Here we are HAL Common in Library API（ Predefined functions , That is, we operate GPIO Function of ）

HAL_GPIO_Init： Initialization pin , Working speed of pins 、 Whether to reuse the mode 、 Up and down parameters .
void HAL_GPIO_Init(GPIO_TypeDef *GPIOx, GPIO_InitTypeDef *GPIO_Init)
example ：HAL_GPIO_Init(GPIOA, &GPIO_InitStructure);

HAL_GPIO_Deinit： After function initialization, the pin returns to the default state , That is, the value when each register is reset
void HAL_GPIO_DeInit(GPIO_TypeDef *GPIOx, uint32_t GPIO_Pin)
example ：HAL_GPIO_DeInit(GPIOA, GPIO_PIN_0|GPIO_PIN_1|GPIO_PIN_2);

HAL_GPIO_ReadPin： Read the level status of the pin 、 The return value of the function is 0 or 1
void HAL_GPIO_WritePin(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin, GPIO_PinState PinState)
example ：HAL_GPIO_WritePin(GPIOA, GPIO_PIN_0,GPIO_PIN_RESET)

HAL_GPIO_WritePin： Write pin level , Pin write 0 or 1
void HAL_GPIO_TogglePin(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
example ：HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_0);

HAL_GPIO_TogglePin： Flip pin level  
void HAL_GPIO_TogglePin(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin)
example ：HAL_GPIO_TogglePin(GPIOA, GPIO_PIN_0);

HAL_GPIO_LockPin： Lock pin level , For example, the current state of a pin is 1, When this pin level changes, the value when locking is maintained .
HAL_StatusTypeDef HAL_GPIO_LockPin(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin);
example ：HAL_GPIO_LockPin(GPIOA, GPIO_PIN_0);    

HAL_GPIO_EXTI_IRQHandler： Interrupt service function of pin , External interrupt service function , Clears the interrupt flag bit     
void HAL_GPIO_EXTI_IRQHandler(uint16_t GPIO_Pin)
example ：HAL_GPIO_EXTI_IRQHandler(GPIO_PIN_3);

HAL_GPIO_EXTI_Callback： Interrupt callback function of pin , It can be understood as the specific action to be responded by the interrupt function .
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
example ：HAL_GPIO_EXTI_Callback(GPIO_Pin);

3、 Digression

In our previous articles, lighting has been used （HAL_GPIO_WritePin） This API, Here we can also use （HAL_GPIO_TogglePin） This API, It can flip the level of the pin , It can also make our code concise and clear .  

while (1){/* USER CODE END WHILE */	   // Running water lamp 	HAL_GPIO_TogglePin(GPIOA,LED0_Pin);	HAL_Delay(250);	HAL_GPIO_TogglePin(GPIOA,LED1_Pin);	HAL_Delay(250);	HAL_GPIO_TogglePin(GPIOA,LED2_Pin);    HAL_Delay(250);}/* USER CODE END 3 */