Arduino - Keypad Door Lock
In this tutorial, we learn how to make door lock system with password using keypad and solenoid lock.
When the door is unlocked by a correct password, It keeps the door unlocked for 20 seconds, and then automatically lock the door again. The Arduino code supports multiple passwords.
※ NOTE THAT:
We also have others door lock system tutorials:
|1||×||Arduino UNO or Genuino UNO|
|1||×||USB 2.0 cable type A/B|
|1||×||12V Power Adapter|
|1||×||DC Power Jack|
About Keypad and Solenoid Lock
If you do not know about solenoid lock and button (pinout, how it works, how to program ...), learn about them in the following tutorials:
- Arduino - Door lock with keypad, solenoid lock
Image is developed using Fritzing. Click to enlarge image
Arduino Code - Door lock system with password using keypad, solenoid lock
- Connect Arduino to PC via USB cable
- Open Arduino IDE, select the right board and port
- On Arduino IDE, Go to Tools Manage Libraries
- Search “keypad”, then find the keypad library by Mark Stanley, Alexander Brevig
- Click Install button to install keypad library.
- Copy the above code and open with Arduino IDE
- Click Upload button on Arduino IDE to upload code to Arduino
- In put a wrong password, and then input a correct password
- See the the lock tongue's state during 20 seconds.
※ NOTE THAT:
- In the above code, To make it simple, we used the delay function. It is better to use millis() instead of delay(). See How to use millis() instead of delay()
- You can add a piezo buzzer to make the beep sound each time keypad is pressed.
- In the above codes, the door is locked again after 20 seconds. You can replace it by a door sensor. The door is locked when the door sensor detect the door is closed by user.
- In the above code, the passwords are hard-coded. In the practice, it should be able to add/delete/change passwords dynamically via a special mode. If so, the passwords should be saved on EEPROM memory. The number of passwords can be saved depends on the EEPROM's size. The code will become complicated. If you want to build such system, we provide a coding service. Please feel free to contact us.
We are considering to make the video tutorials. If you think the video tutorials are essential, please subscribe to our YouTube channel to give us motivation for making the videos.