#Arduino door lock with keypad code

The following code will compare the entered key with the password stored in the EEPROM. Arduino will read keys one by one and make a beep sound whenever a key is pressed.

The following code will read pressed keys from the keypad and will show it on LCD as well as in serial monitor.

Then giving command to start the LCD, setting buzzer and make LED pins as output. Digital Door Lock using Arduino Uno Arduino Code or Sketch #include īyte rowPins = //connect to the column pinouts of the keypad If we enter the correct password it will ask for new passkey and will save it in the EEPROM. When we press ‘#’, it will ask for current passkey. The buzzer will also beep once when any key is pressed.įor changing the passkey, we have to press ‘#’. During this condition the buzzer will start beeping and the push pull solenoid will remain in the high state (Door Locked). If the password is wrong, then it will show ‘Access Denied’. If it is correct, then it will show ‘Passkey Accepted’ and the push pull solenoid will come in low state (Door Unlocked). When we enter a password, it will match it with the password stored in the Arduino EEPROM. The default password stored in it will be ‘1234’. In this project, we have used EEPROM in the Arduino to store the password in it. Larger values will make the back light much more darker. By changing this resitor value we can change the backlight LED brightness. Connect pin 15 to the VCC through the 220 ohm resistor.Connect pin 14 (D7) to pin 4 of Arduino.Connect pin 13 (D6) to pin 5 of Arduino.Connect pin 12 (D5) to pin 6 of Arduino.Connect pin 11 (D4) to pin 7 of Arduino.The following four pins are data pins which are used to send data or commands to the LCD.It is used indicate a valid data or command in the following data pins. Connect pin 6 (E) to the pin 8 of the Arduino.This pin is not often used so we will connect it to the ground as we are only writing data to LCD. Connect pin 5 (Read/Write) to the ground of Arduino.This is Register Select pin used to select a particular register in the LCD driver, which is handled by the LCD library. Connect pin 4 (RS) to the pin 9 of the Arduino.The potentiometer is used to control the contrast of the LCD. Connect pin 3 (V0) to the middle pin of the 10KΩ potentiometer and connect the other two ends of the potentiometer to VCC and GND.Connect pin 2 (VDD or VCC) to the 5V of the Arduino.Now we will connect the 16×2 LCD to the Arduino. Now connect the positive wire of buzzer to the pin 10 of Arduino and negative wire to the ground. Now connect the positive of power supply to the positive wire of solenoid and the negative of power supply to the ground. So, connect its first pin (which is the base pin) to the pin 11 through to a 1KΩ resistor, second pin (which is the collector pin) to the negative wire of push pull solenoid and third pin (which is the emitter pin) to the ground. The NPN transistor will switch ON when we will give HIGH to its base.

So to do that, we will use TIP120 NPN transistor as a switch/driver and a DC power source which can provide 6 ~ 12V. To connect the push pull solenoid with the Arduino, we will have to use external power because it requires 6 ~ 12V to operate and much more current than the Arduino can provide. Connect first six pins of keypad to analog pins A0 ~ A5 of Arduino and remaining two to digital pins 3 and 2. We used analog pins since we need more that 14 digitals pins for this project. If you are using Arduino Mega, then there is no need to use analog pins. For connecting the keypad with the Arduino we are using both analog and digital pins. Components RequiredĬircuit Diagram & Explanation Digital Door Lock using Arduino – Circuit Diagramįirst of all, we will make the connection to the 4×4 Keypad. It will open your door only when the right password is entered and it will start beeping when a wrong password is entered. In this project we will make a digital door lock system with keypad using Arduino Uno. As thefts are increasing day by day security is becoming a major concern nowadays.

Arduino door lock with keypad