//BY LINZH_BME_SEU

//頭文件
#include "hw_memmap.h"
#include "hw_types.h"
#include "gpio.h"
#include "sysctl.h"

//宏



//函數

void KeyInit(void);	//初始化
void SetLine(unsigned int x,unsigned char a); //開第x排
unsigned char GetRow(unsigned int y); //讀第y列
unsigned char KeyPress_base(void);	//是否有鍵按下
unsigned char KeyScan_base(void); //哪個鍵正被按著，0～15中最前的一個y
void KeyDelay(unsigned int x);//延時

unsigned char KeyPress(void);	//消抖
unsigned char KeyScan(); //消抖

unsigned char KeyRelease(); //釋放

//初始化

void KeyInit(void) 
{
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOD);
	GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE,GPIO_PIN_0);
  	GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE,GPIO_PIN_1);
  	GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE,GPIO_PIN_2);
	GPIOPinTypeGPIOOutput(GPIO_PORTD_BASE,GPIO_PIN_3);
	GPIOPinTypeGPIOInput(GPIO_PORTD_BASE,GPIO_PIN_4);
  	GPIOPinTypeGPIOInput(GPIO_PORTD_BASE,GPIO_PIN_5);
  	GPIOPinTypeGPIOInput(GPIO_PORTD_BASE,GPIO_PIN_6);
	GPIOPinTypeGPIOInput(GPIO_PORTD_BASE,GPIO_PIN_7);
}

//開第x排

void SetLine(unsigned int x,unsigned char a)
{
        unsigned char b=a<<x;
	if(x==0) GPIOPinWrite(GPIO_PORTD_BASE,GPIO_PIN_0,b);
	else if(x==1) GPIOPinWrite(GPIO_PORTD_BASE,GPIO_PIN_1,b);
	else if(x==2) GPIOPinWrite(GPIO_PORTD_BASE,GPIO_PIN_2,b);
	else if(x==3) GPIOPinWrite(GPIO_PORTD_BASE,GPIO_PIN_3,b);
}

//讀第y列

unsigned char GetRow(unsigned int y)
{
        unsigned char b;
	if(y==0) b= GPIOPinRead(GPIO_PORTD_BASE,GPIO_PIN_4);
	else if(y==1) b= GPIOPinRead(GPIO_PORTD_BASE,GPIO_PIN_5);
	else if(y==2) b=  GPIOPinRead(GPIO_PORTD_BASE,GPIO_PIN_6);
	else if(y==3) b=  GPIOPinRead(GPIO_PORTD_BASE,GPIO_PIN_7);
	else b=0;
        if(b!=0) b=1;
        return b;
        
}

//是否有鍵按下

unsigned char KeyPress_base(void)
{
	unsigned int i;
	for(i=0;i<4;i++) SetLine(i,1);
	for(i=0;i<4;i++) 
	{
		if(GetRow(i)==1) return 1;
	}
        return 0;
}

//掃描

unsigned char KeyScan_base(void)
{
	unsigned int x,y;
	for (x=0;x<4;x++)
	{
		SetLine(x,1);
		SetLine((x+1)%4,0);
		SetLine((x+2)%4,0);
		SetLine((x+3)%4,0);
		for (y=0;y<4;y++)
		{
			if(GetRow(y)==1) return x*4+y;
		}
	}
	return 16; //未按下
}

//延時

void KeyDelay(unsigned int x)
{
        unsigned int da,db;
	for(da=0;da<x;da++)
	for(db=0;db<1000;db++);
}

//消抖的

unsigned char KeyPress(void)
{ 
  if(KeyPress_base()==1)
  {
    KeyDelay(100);
    if(KeyPress_base()==1) return 1;
  }
  return 0;
}


unsigned char KeyScan(void)
{
  unsigned char k=KeyScan_base();
  KeyDelay(100);
  if(KeyScan_base()==k) return k;
  else return 16;
}


unsigned char KeyRelease(void)
{
  unsigned char k1;
  k1=KeyScan_base();
  if(k1!=16)
  {
    KeyDelay(100);
    if(KeyScan_base()!=k1) return 16;
    
    unsigned int x,y;
    x=k1/4;
    y=k1%4;
    SetLine(x,1);
    SetLine((x+1)%4,0);
    SetLine((x+2)%4,0);
    SetLine((x+3)%4,0);
    while(GetRow(y)==1);
    return k1;
  }  
  return 16;
}