G8: Password Based Door Lock System - shalan/CSCE4301-WiKi GitHub Wiki

Password Based Door Lock System

Contributors:

Ahmed Ali 900171421
Zaki Elsayed 900171230

Github Repo:

https://github.com/a9aly/Door-Lock-System

Project Description:

With the increased demand for smart systems that provides more flexibility and security, people started looking for alternatives to replace their old downgraded systems. In Our project we aim to provide one of these smart solutions that provide more security, which is a password based door locking system circuit designed using STM32l432kc microcontroller. A secure password will act as a door unlocking system instead of keys. Our project will be an integration of mechanical and electronic devices and it will consist of electronic control assembly, which controls the output load through a password and this output load is the Servo Motor.

Hardware Components:

STM32l432kc Microcontroller
16*2 LCD Display
Active Buzzer
Mobile Phone "Supports Bluetooth"
Servo Motor
HC05 or HC06 module
Ultrasonic Sensor HC-SR04
Optional:

USB to TTL Serial Converter "Replaces Mobile Phone"

Software Components

Keil uVision
CubeMX
Bluetooth Terminal on Mobile Phone
Optional:

Tera Term "In USB to TTL Serial Converter Case"

System Design

Method Draw Image

Input

Entering Password Via Mobile Phone Keypad "Only numbers 0-9 are acceptable".
Distance between the door and surroundings for auto-lock technique.

Output

LCD Display providing user interface.
Buzzer produce an alarm in case of wrong password entry for many times.
Servo Motor locks and unlocks the door.
Duration remaining for the door until it locks again.

Communication:

LCD display instructions to user.
User will interface with the STM32l432kc via mobile keypad.
STM32l432kc analyzes and computes user input to produce output.
Servo Motor acts as door lock/unlock.

How it works:

1 - The user is asked whether he wants to enter pin to unlock the door or reset pin "which is by default it's 1,1,1,1".

2 - User enters his choice through mobile keypad.

3 - In case the user wants to unlock the door: if pins match, PWM signal is generated with certain duty cycle to rotate the servo motor.

4 - if pins does not match the user has 2 more chances to re-enter pin before an alarm starts buzzing.

5 - To stop the buzzer the user has to enter the correct password.

6 - In case the user wants to reset the pin: he is asked to enter the old pin.

7 - If pins match, user is asked to enter the new password.

8 - If pins does not match, the user has only 2 more chances to re-enter pin before an alarm starts buzzing with the same stopping condition mentioned above.

9 - While the door is open and with the aid of ultrasonic sensor, the distance between the door and any passing object is calculated.

10 - If calculated distance is more than ~ 100cm (1m) "No one is passing", the LCD display time remaining until the door is locked and door is locked after 10 seconds.

11 - If calculated distance is less than ~ 100cm (1m) "Someone is passing", the period of 10 seconds starts over.

Servo Motor

Timer Setup (with 50Hz output and 20ms cycle)

My clock frequency is 4MHZ.

To get 50HZ ->> 4MHz/[(1+799)(1+99)] = 50Hz

Then I need to change the duty cycle as mentioned below and according to values in data sheet to rotate the motor for 90 degrees.

Timer Setup

Coding

LCD

We are using LCD 16*2 in 4 bit mode to allow more space for other peripherals in our microcontroller. In this mode we send data as upper 4bits (D4-D7) at once.

LCD APIs

LCD_INIT

LCD_SEND_DATA

LCD_Clear_Screen

LCD_Mark_DATA

LCD_Print_String

LCD_Print_Charachter

LCD_Move_Cursor

LCD_Print_Start_Message

LCD_Asking_User_Input

For More Details You Can Check Links in Reference Under LCD.

Challenges:

LCD communications.
Servo Motor application.
Integrating all components and using parallel timers for different purposes.
Surely Wiring.

Limitations and some possible modifications:

User cannot unlock the door without having Bluetooth on his mobile phone. "Keypad can solve this situation".
In case of power failure, password resets to its default value again '1,1,1,1'. "Either provide an alternative electric source in cases of emergency or provide a memory to keep passwords".
It is better to replace the ultrasonic sensor with infrared sensor to detect infrared radiations in the surrounding environment and detect the presence of anyone around the door, to activate auto lock.

Flow Chart

Flowchart

Connections

Project Final

Milestones

Demo goes as following:

1 - First, I choose to unlock the door and I input the correct pin numbers, so the servo motor rotates "representing unlocking the door".

2 - Distances readings are taken and time remaining is updated every 2 seconds for 10 seconds period. I pass my hand in front of the sensor and the period starts over again. After the end of the period the lock locks itself.

3 - Then I test resetting the password, I enter the right pin and I am allowed to set a new pin, otherwise I see a message that I entered a wrong pin and am not allowed to change the current pin.

4 - After 3 wrong pin entry trials, the buzzer goes on and produce a tone that never goes silent unless I put the right pin.

Pictures showing some LCD outputs:

WhatsApp Image 2021-05-27 at 8 20 50 AM (3)