Simple password lock

This section simulates the smart door lock , be based on 51 The four digit simple password lock made under the single chip microcomputer

The modules used are LCD1602 LCD screen （ Used to display the entered password ） and Matrix key （ Used to enter a password ）

The specific code is as follows ：
LCD1602 Previously described in detail , Only the functions that need to be used are listed here , For details, please click “ LCD1602 Liquid crystal display (LCD) ”
LCD1602.c

/** * @brief  stay LCD1602 Start displaying the given number at the specified position  * @param Line  Start line position , Range ：1~2 * @param Column  Start column position , Range ：1~16 * @param Number  Number to display , Range ：0~65535 * @param Length  The length of the number to display , Range ：1~5 * @retval  nothing  */			
void LCD_ShowNum(unsigned char Line,unsigned char Column,unsigned int Number,unsigned char Length)			
{
    			
	unsigned char i;		
	LCD_SetCursor(Line,Column);		
	for(i=Length;i>0;i--)		
	{
    		
		LCD_WriteData(Number/LCD_Pow(10,i-1)%10+'0');	
	}		
}	

/** * @brief  stay LCD1602 Start displaying the given string at the specified position  * @param Line  Start line position , Range ：1~2 * @param Column  Start column position , Range ：1~16 * @param String  String to display  * @retval  nothing  */			
void LCD_ShowString(unsigned char Line,unsigned char Column,char *String)			
{
    			
	unsigned char i;		
	LCD_SetCursor(Line,Column);		
	for(i=0;String[i]!='\0';i++)		
	{
    		
		LCD_WriteData(String[i]);	
	}		
}	

Matrixkey.c

unsigned char MatrixKey()
{
    

	key=0x0f;
	if(key!=0x0f)
	{
    
		Delay(100);
		if(key!=0x0f)
		{
    
			key=0x0f;
			switch(key)
			{
    
				case 0x07 : keyvalue=1;break;
				case 0x0b : keyvalue=2;break;
				case 0x0d : keyvalue=3;break;
				case 0x0e : keyvalue=4;break;
			}
			key=0xf0;
			switch(key)
			{
    
				case 0x70 : keyvalue=keyvalue;break;
				case 0xb0 : keyvalue=keyvalue+4;break;
				case 0xd0 : keyvalue=keyvalue+8;break;
				case 0xe0 : keyvalue=keyvalue+12;break;
			}
			return keyvalue;
		}
	}
}

main.c

void main()
{
    	
	LCD_Init();							//LCD initialization 
	LCD_ShowString(1,1,"Input Keys :");	//LCD display string 
	while(1)
	{
    
		t=MatrixKey();				// Get matrix keyboard key code 
		if(t)						// If a key is pressed 
		{
    
			if(t<=10)
			{
    
				if(cot<4)
				{
    
					keys=keys*10;
					keys=keys+t%10;
					cot++;
				}
			    LCD_ShowNum(2,1,keys,4);//LCD Display password 
			}
				if(t==11)
				{
    
					if(keys==1102)
					{
    
						LCD_ShowString(1,14,"OK ");
						keys=0;
						cot=0;
						LCD_ShowNum(2,1,keys,4);//LCD Display password 
					}
					else
					{
    
						LCD_ShowString(1,14,"ERR");
						keys=0;
						cot=0;
						LCD_ShowNum(2,1,keys,4);//LCD Display password 
					}
				}
				if(t==12)
				{
    
					keys=0;
					cot=0;
					LCD_ShowNum(2,1,keys,4);
				}
		}
	}
}