Electronic code lock using 8051 microcontroller

A 4x3 framework keypad and a 16x2 LCD have been utilized here. Keypad and LCD are exceptionally regularly utilized enter & yield units, separately. A four digit predefined watchword should be specified the user. This secret word is saved in the framework. 

While unlocking, if the dropped in watchword from keypad matches with the archived secret key, then the lock opens and a note is shown on LCD. Moreover a yield bind is made elevated to be utilized for further reason. 

The associations in the circuit are as taking after: port P2 of microcontroller AT89C51 is utilized as information include port which is joined with information binds (7-14) of LCD. P1^0, P1^1 and P1^2 binds of microcontroller are joined with control binds RS, RW and EN of LCD. Port P0 is utilized to take include from keypad. P0^7 has been utilized as lock yield bind of controller. 

As the project begins, string ‘Enter Password’ is shown on LCD. The keypad is checked for pressed digits one by one. Unfailingly, column and section of the nexus pressed is located and a ‘*’ is shown on LCD relating to the dropped in number. When the four digits are dropped in, the user is incited to ‘Confirm Password’ and again the info is taken through LCD. Depending on if the passwords don't match, a note is shown to demonstrate ‘Wrong Password’; generally the user is incited to unlock the apparatus. 

To unlock, user should ‘Enter Password’ through keypad. Again the keypad is examined for pressed keys and comparing digits are distinguished. The passkey is shown as ‘****’ on the LCD screen. When the four digits are dropped in, they are contrasted and the pre-set watchword. Provided that every last trace of the four digits match with set watchword, LCD presentations ‘Lock Open’ and the lock yield bind goes elevated. Depending on if the security code is wrong, ‘Wrong Password’ is sent to be shown on LCD. The framework inches toward getting bolted if more than several endeavors are made with wrong secret key to open the electronic bolt. The framework should be reset in quite an impressive case. 

//Program to make a code lock with user defined password #include<reg51.h> #define port P1 #define dataport P2 #define key P0 #define sec 100 sbit rs = port^0; sbit rw = port^1; sbit en = port^2; sbit col1=key^4; sbit col2=key^5; sbit col3=key^6; sbit row1=key^0; sbit row2=key^1; sbit row3=key^2; sbit row4=key^3; sbit lock_output=P0^7; int check=0; int digit[4]={0,0,0,0}; int dig_input[4]={0,0,0,0}; int dig_input_recheck[4]={0,0,0,0}; int i,k; void delay(unsigned int msec) // Time delay function { int i,j ; for(i=0;i<msec;i++) for(j=0;j<1275;j++); } void lcd_cmd(unsigned char item) // Function to send command to LCD { dataport = item; rs= 0; rw=0; en=1; delay(1); en=0; return; } void lcd_data(unsigned char item) // Function to send data to LCD { dataport = item; rs= 1; rw=0; en=1; delay(1); en=0; return; } void lcd_data_string(unsigned char *str) // Function to send data to string { int i=0; while(str[i]!='\0') { lcd_data(str[i]); i++; //delay(10); } return; } void lcd(unsigned char str[10]) { lcd_cmd(0x38); lcd_cmd(0x0e); lcd_data_string(str); } void ans() { if(check>3) { lcd_cmd(0x01); lcd_cmd(0x82); lcd_data_string(" LOCK OPEN"); lock_output=1; delay(300); while(1); } else { lcd_cmd(0x01); lcd_cmd(0x82); lcd_data_string(" WRONG PASSWORD"); lock_output=0; delay(300); } } void code_check() // Function to check password { if(i<=3 ) { switch((i+1)) { case 1: { if(dig_input[0]==digit[0]) { check=check+1; } break; } case 2: { if(dig_input[1]==digit[1]) { check=check+1; } break; } case 3: { if(dig_input[2]==digit[2]) { check=check+1; } break; } case 4: { if(dig_input[3]==digit[3]) { check=check+1; } break; } } } delay(10); if(i==3) { ans(); } } void display(int a) //Display function { switch(a) { case 1:{ lcd_data('*'); delay(100); digit[i]=1; code_check(); break; } case 2:{ lcd_data('*'); delay(100); digit[i]=2; code_check(); break; } case 3:{ lcd_data('*'); delay(100); digit[i]=3; code_check(); break; } case 4:{ lcd_data('*'); delay(100); digit[i]=4; code_check(); break; } case 5:{ lcd_data('*'); delay(100); digit[i]=5; code_check(); break; } case 6:{ lcd_data('*'); delay(100); digit[i]=6; code_check(); break; } case 7:{ lcd_data('*'); delay(100); digit[i]=7; code_check(); break; } case 8:{ lcd_data('*'); delay(100); digit[i]=8; code_check(); break; } case 9:{ lcd_data('*'); delay(100); digit[i]=9; code_check(); break; } case 0:{ lcd_data('*'); delay(100); digit[i]=0; code_check(); break; } } } void check_col1() { row1=row2=row3=row4=1; row1=0; if(col1==0) display(1); row1=1; row2=0; if(col1==0) display(4); row2=1; row3=0; if(col1==0) display(7); row3=1; row4=0; if(col1==0) { row4=1; } } void check_col2() { row1=row2=row3=row4=1; row1=0; if(col2==0) display(2); row1=1; row2=0; if(col2==0) display(5); row2=1; row3=0; if(col2==0) display(8); row3=1; row4=0; if(col2==0) display(0); row4=1; } void check_col3() { row1=row2=row3=row4=1; row1=0; if(col3==0) display(3); row1=1; row2=0; if(col3==0) display(6); row2=1; row3=0; if(col3==0) display(9); row3=1; row4=0; if(col3==0) { row4=1; } } void check_password_col1() { row1=row2=row3=row4=1; row1=0; if(col1==0) dig_input[k]=1; row1=1; row2=0; if(col1==0) dig_input[k]=4; row2=1; row3=0; if(col1==0) dig_input[k]=7; row3=1; row4=0; if(col1==0) { row4=1; } } void check_password_col2() { row1=row2=row3=row4=1; row1=0; if(col2==0) dig_input[k]=2; row1=1; row2=0; if(col2==0) dig_input[k]=5; row2=1; row3=0; if(col2==0) dig_input[k]=8; row3=1; row4=0; if(col2==0) { dig_input[k]=0; row4=1; } } void check_password_col3() { row1=row2=row3=row4=1; row1=0; if(col3==0) dig_input[k]=3; row1=1; row2=0; if(col3==0) dig_input[k]=6; row2=1; row3=0; if(col3==0) dig_input[k]=9; row3=1; row4=0; if(col3==0) { row4=1; } } void pass_set() { row1=row2=row3=row4=0; while(col1==1 && col2==1 && col3==1); for(i=0;i<4;i++) { k=i; delay(50); lcd_cmd(0xc4+i); delay(100); row1=row2=row3=row4=0; while(col1==1 && col2==1 && col3==1); row1=row2=row3=row4=0; if(col1==0) check_password_col1(); else if(col2==0) check_password_col2(); else if(col3==0) check_password_col3(); lcd_data('*'); delay(50); } } void main() { int e,j=0,count=1; col1=col2=col3=1; //FOR PASSWoRD INPUT do { lcd_cmd(0x01); //Clear LCD screen lcd_cmd(0x81); lcd("ENTER PASSWORD:"); pass_set(); for(e=0;e<4;e++) dig_input_recheck[e]=dig_input[e]; lcd_cmd(0x01); lcd("CONFIRM PASSWORD:"); pass_set(); for(e=0;e<4;e++) { if(dig_input_recheck[e]==dig_input[e]) j++; } if(j<4) { lcd_cmd(0x01); lcd_cmd(0x85); lcd("PASSWORD"); lcd_cmd(0xC2); lcd("NOT MATCH"); delay(300); } } while(j<4); while(count<4) //Code input and check { lcd_cmd(0x01); lock_output=0; lcd_cmd(0x82); lcd("ENTER PASSWORD"); check=0; row1=row2=row3=row4=0; while(col1==1 && col2==1 && col3==1); for(i=0;i<4;i++) { delay(100); lcd_cmd(0xc4+i); row1=row2=row3=row4=0; while(col1==1 && col2==1 && col3==1); row1=row2=row3=row4=0; if(col1==0) check_col1(); else if(col2==0) check_col2(); else if(col3==0) check_col3(); } count++; delay(1); } if(count==4) { lcd_cmd(0x01); lcd_cmd(0x86); lcd("SORRY"); lcd_cmd(0xc1); lcd("NO MORE TRIALS"); while(1); } }