STM32实战 2.矩阵键盘通过串口3输出

#include "KEY44.h"
#include "sys.h"
#include "delay.h"
#include "usart.h"

u8 key_num = 0;

int main(void)
{	
		uart_init(115200);
		delay_init();
		KEY44_Init();
	
	while(1)
	{
		key_num = key44_Scan();
		if(key_num != 0)
		{
		printf("KEY is %d\r\n",key_num);
		}
	}
	
}

#include "KEY44.h"
#include "sys.h"
#include "delay.h"


void  KEY44_Init(void)
{
		GPIO_InitTypeDef GPIO_InitStructure;
		RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA,ENABLE);
		GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 |GPIO_Pin_1 |GPIO_Pin_2 |GPIO_Pin_3;
		GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
		GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
		GPIO_Init(GPIOA, &GPIO_InitStructure);
	
		GPIO_InitStructure.GPIO_Pin = GPIO_Pin_4 |GPIO_Pin_5 |GPIO_Pin_6 |GPIO_Pin_7;
		GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
		GPIO_InitStructure.GPIO_Mode = GPIO_Mode_IPU;
		GPIO_Init(GPIOA, &GPIO_InitStructure);
}

unsigned char key44_Scan(void)
{
			H_1 = 0;
			H_2 = 1;
			H_3 = 1;
			H_4 = 1;

	if( L_1 == 0)
	{
		delay_ms(10);
		if(L_1 == 0)
		{
			while(!L_1);
			return 1;
		}
	}
	if(L_2 == 0)
	{
		delay_ms(10);
		if(L_2 == 0)
		{
			while(!L_2);
			return 2;
		}
	}
	if(L_3 == 0)
	{
		delay_ms(10);
		if(L_3 == 0)
		{
			while(!L_3);
			return 3;
		}
	}
	if(L_4 == 0)
	{
		delay_ms(10);
		if(L_4 == 0)
		{
			while(!L_4);
			return 4;
		}
	}

	H_1 = 1;
	H_2 = 0;
	H_3 = 1;
	H_4 = 1;

	if(L_1 == 0)
	{
		delay_ms(10);
		if(L_1 == 0)
		{
			while(!L_1);
			return 5;
		}
	}
	if(L_2 == 0)
	{
		delay_ms(10);
		if(L_2 == 0)
		{
			while(!L_2);
			return 6;
		}
	}
	if(L_3 == 0)
	{
		delay_ms(10);
		if(L_3 == 0)
		{
			while(!L_3);
			return 7;
		}
	}
	if(L_4 == 0)
	{
		delay_ms(10);
		if(L_4 == 0)
		{
			while(!L_4);
			return 8;
		}
	}

	H_1 = 1;
	H_2 = 1;
	H_3 = 0;
	H_4 = 1;

	if(L_1 == 0)
	{
		delay_ms(10);
		if(L_1 == 0)
		{
			while(!L_1);
			return 9;
		}
	}
	if(L_2 == 0)
	{
		delay_ms(10);
		if(L_2 == 0)
		{
			while(!L_2);
			return 10;
		}
	}
	if(L_3 == 0)
	{
		delay_ms(10);
		if(L_3 == 0)
		{
			while(!L_3);
			return 11;
		}
	}
	if(L_4 == 0)
	{
		delay_ms(10);
		if(L_4 == 0)
		{
			while(!L_4);
			return 12;
		}
	}

	H_1 = 1;
	H_2 = 1;
	H_3 = 1;
	H_4 = 0;

	if(L_1 == 0)
	{
		delay_ms(10);
		if(L_1 == 0)
		{
			while(!L_1);
			return 13;
		}
	}
	if(L_2 == 0)
	{
		delay_ms(10);
		if(L_2 == 0)
		{
			while(!L_2);
			return 14;
		}
	}
	if(L_3 == 0)
	{
		delay_ms(10);
		if(L_3 == 0)
		{
			while(!L_3);
			return 15;
		}
	}
	if(L_4 == 0)
	{
		delay_ms(10);
		if(L_4 == 0)
		{
			while(!L_4);
			return 16;
		}
	}
	return 0;
}

#ifndef __KEY44_H
#define __KEY44_H	 

	//PA0~PA3为推挽式输出
//PA4~PA7为上拉式输入	

#define H_1 PAout(0)
#define H_2 PAout(1)
#define H_3 PAout(2)
#define H_4 PAout(3)

#define L_1 PAin(4)
#define L_2 PAin(5)
#define L_3 PAin(6)
#define L_4 PAin(7)

void  KEY44_Init(void);
unsigned char key44_Scan(void);		    
#endif