【藍橋杯嵌入式】2_KEY

1 原理圖

按鍵同I/O的映射關係：
B1~B4—PA0、PA8、PB1、PB2

2 部分源碼

實驗：實現LCD第四行0-10隨按鍵滾動。

主循環掃描實現

main.c:

#include "HeadFile.h"

u8 KeyCount = 0;

u8 KeySta[4] = {
	1, 1, 1, 1
};
u8 KeyMap[5] = {
	'A', 'B', 'C', 'D'
};

void KeyInit(){
	GPIO_InitTypeDef GPIOInitStructure;
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA|RCC_APB2Periph_GPIOB,ENABLE);
	GPIOInitStructure.GPIO_Pin = GPIO_Pin_0|GPIO_Pin_8;
	GPIOInitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOA,&GPIOInitStructure);
	GPIOInitStructure.GPIO_Pin = GPIO_Pin_1|GPIO_Pin_2;
	GPIOInitStructure.GPIO_Mode = GPIO_Mode_IN_FLOATING;
	GPIO_Init(GPIOB,&GPIOInitStructure);
}

void KeyScan(){
	u8 index = 0;
	static u8 KeyBuffer[4] = {
		0xFF, 0xFF, 0xFF, 0xFF
	}; 
	KeyBuffer[0] = (KeyBuffer[0] << 1) | K1;
	KeyBuffer[1] = (KeyBuffer[1] << 1) | K2;
	KeyBuffer[2] = (KeyBuffer[2] << 1) | K3;
	KeyBuffer[3] = (KeyBuffer[3] << 1) | K4;
	
	for(index = 0; index < 4; index ++){
		if(KeyBuffer[index] == 0xFF ){
			KeySta[index] = 1;
		}else if(KeyBuffer[index] == 0x00){
			KeySta[index] = 0;
		}
	}

}

void KeyDriver(){
	u8 index = 0;
	static u8 KeyBackup[4] = {
		1, 1, 1, 1
	};
	
	for(index = 0; index < 4; index ++){
		if(KeySta[index] != KeyBackup[index] ){
			KeyBackup[index] = KeySta[index];
			if(KeySta[index] == 0){
				KeyAction(KeyMap[index]);
			}
		}
	}
	
}

void KeyAction(u8 CMD){
	u8 Display;
	if(CMD == 'A'){
		KeyCount ++;
	}else if(CMD == 'B'){
		KeyCount += 2;
	}else if(CMD == 'C'){
		KeyCount += 3;
	}else if(CMD == 'D'){
		KeyCount += 4;
	}
	if(KeyCount >= 10){
		KeyCount -= 10;
	}
	Display = '0'+KeyCount;
	LCD_DisplayStringLine(Line4,&(Display));

}

外部中斷實現

外部中斷配置過程：
1、初始化IO口（設置輸入狀態和時鐘）
2、設置IO口和中斷線的映射關係
3、設置中斷觸發方式等
4、配置中斷分組
5、編寫中斷服務函數
6、清除中斷標誌位

Tips:中斷服務函數格式：

void EXTI3_IRQHandler(void)
{
  if(EXTI_GetITStatus(EXTI_Line3)!=RESET)//判斷某個線上的中斷是否發生 
  {
    中斷邏輯…
    EXTI_ClearITPendingBit(EXTI_Line3); //清除 LINE 上的中斷標誌位 
  } 
}

#include "Headfile.h"

u8 Display;
u8 KeyCount = 0;

void EXTIInit(){
	EXTI_InitTypeDef EXTI_InitStructure;
	NVIC_InitTypeDef NVIC_InitStructure;
	//1、初始化IO口（設置輸入狀態和時鐘）
	KeyInit();
	
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO,ENABLE);//使能複用IO
	//KEY1
	//2、設置IO口和中斷線的映射關係
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource0);
	EXTI_InitStructure.EXTI_Line = EXTI_Line0;
	//3、設置中斷觸發方式等
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_Init(&EXTI_InitStructure);
	//4、配置中斷分組
	NVIC_InitStructure.NVIC_IRQChannel = EXTI0_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
	//KEY2
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOA,GPIO_PinSource8);
	EXTI_InitStructure.EXTI_Line = EXTI_Line8;
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_Init(&EXTI_InitStructure);
	NVIC_InitStructure.NVIC_IRQChannel = EXTI9_5_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
	//KEY3
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource1);
	EXTI_InitStructure.EXTI_Line = EXTI_Line1;
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_Init(&EXTI_InitStructure);NVIC_InitStructure.NVIC_IRQChannel = EXTI1_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
	//KEY4
	GPIO_EXTILineConfig(GPIO_PortSourceGPIOB,GPIO_PinSource2);
	EXTI_InitStructure.EXTI_Line = EXTI_Line2;
	EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
	EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Falling;
	EXTI_InitStructure.EXTI_LineCmd = ENABLE;
	EXTI_Init(&EXTI_InitStructure);
	NVIC_InitStructure.NVIC_IRQChannel = EXTI2_IRQn;
	NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 2;
	NVIC_InitStructure.NVIC_IRQChannelSubPriority = 3;
	NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
	NVIC_Init(&NVIC_InitStructure);
	
}
//5、編寫中斷服務函數
void EXTI0_IRQHandler(void){
	if(EXTI_GetITStatus(EXTI_Line0)!=RESET){
		KeyCount ++;
		if(KeyCount >= 10){
			KeyCount -= 10;
		}
		Display = '0'+KeyCount;
		LCD_DisplayStringLine(Line4,&(Display));
		//6、清除中斷標誌位
		EXTI_ClearITPendingBit(EXTI_Line0);
	}
}

void EXTI9_5_IRQHandler(void){
	if(EXTI_GetITStatus(EXTI_Line8)!=RESET){
		KeyCount +=2;
		if(KeyCount >= 10){
			KeyCount -= 10;
		}
		Display = '0'+KeyCount;
		LCD_DisplayStringLine(Line4,&(Display));
		EXTI_ClearITPendingBit(EXTI_Line8);
	}
}

void EXTI1_IRQHandler(void){
	if(EXTI_GetITStatus(EXTI_Line1)!=RESET){
		KeyCount +=3;
		if(KeyCount >= 10){
			KeyCount -= 10;
		}
		Display = '0'+KeyCount;
		LCD_DisplayStringLine(Line4,&(Display));
		EXTI_ClearITPendingBit(EXTI_Line1);
	}
}

void EXTI2_IRQHandler(void){
	if(EXTI_GetITStatus(EXTI_Line2)!=RESET){
		KeyCount +=4;
		if(KeyCount >= 10){
			KeyCount -= 10;
		}
		Display = '0'+KeyCount;
		LCD_DisplayStringLine(Line4,&(Display));
		EXTI_ClearITPendingBit(EXTI_Line2);
	}
}

注意：外部中斷中不可以使用滴答定時器的延時函數不然會死機！！！