LCD Smart Lock
A lock a few buddies & I made for school.
Most locks today are very outdated and insecure. Also, it can take time to fiddle with keys or put in a passcode. Our lock will solve this by being mostly digital, not physical, making it safer, and will have an option to use an RFID tag instead of a passcode to save time.
Our project is an electromagnetic lock. It works by having an electromagnet on the lock connect to a piece of metal on the door. When a passcode is put in using buttons on the LCD screen or the RFID chip is activated, the electromagnet is turned off and the lock is inactive, using no moving parts at all. A motion sensor turns on the screen when someone goes near the door, and when an incorrect password or RFID tag is entered, a buzzer sounds. The relay is used to turn on the electromagnet.
Although, note, we had to get rid of the RFID tag.
A motion sensor is a device which detects movement or motion of objects within a certain area. It is used particularly in security cameras to detect movement. Most motion sensors detect infrared waves (heat waves). For the prototype the motion sensor will be used for turning the shield off and on which will save energy and battery life as the battery is not needed until someone touches the shield. This will allow the Arduino to not work as hard. When motion is detected it will trigger the shield to activate turning on the battery.
The servo is a small device that has an output shaft. This will be used as a mechanical mechanism to open and close the door. The servo will rotate in a particular direction to put the lock in the door. The servo will maintain in its position until the user plugs in the code. This will trigger the servo to lift the lock up to open the door. The servo rotates in a particular direction to trigger something to happen. It works by sending a pulse of a coded signal to the servo and draws power proportional to the mechanical load. The servo will maintain this position until another instruction is demanded.
A buzzer is an audio signalling device which can be either mechanical or electromechanical. A buzzer requires an AC (Altering Current) signal to make a sound. Changing input signal produces the specific sound. For the prototype the buzzer will be used so when the passcode is typed in wrong the buzzer will make a loud sound signalling to the user that the passcode is incorrect. This acts as an alarm system making sure that the user is unable to get through the door.
An LCD keypad is a device which allows a user to go through the menu and make selections. It is a form of projection and is used for displaying data. The LCD keypad is a display device which will be used to input the passcode into the mechanism. This is an essential part of this project as the passcode is the main appliance needed for the security aspect of this project. The LCD keypad will placed on the side of the door covering the Arduino which will allow the user to have good visibility of the keypad and allow easy access. The LCD keypad will have four buttons for moving the up and down button and the side to side button.