LockedOut

Inspiration

With Buzzcard activated locks becoming more widespread, students commonly get locked out of their room due to forgetting their Buzzcard. To solve this problem, we created an additional door unlocking mechanism that uses a keypad for authentication.

What it does

There are two ESP32 microcontrollers, one on each side of the door.

The ESP32 outside of the door takes input from a capacitive touch keypad. The user enters a 5-digit code. The current entry is displayed on an LCD screen. Upon entering a correct code, the outside ESP32 sends data to the ESP on the other side, telling it to open the door.

The ESP on the other side of the door controls a linear actuator, which pushes the door handle down to unlock the door.

Through the IoT platform Blynk, a user can interact with the lock system from their phone, to send data like a new passcode to the system and to receive notifications upon the door opening. stepper motor. Using a 3D printed gear connected to the motor and a bar with teeth, we implemented a linear actuator. The actuator pushes the door handle down to unlock the door.

We also utilize Blynk, an IoT platform, to provide an interface for the user to interact with the door lock. Blynk allows a phone to send data to an ESP32 and vice versa. Currently, the user can change the door lock’s password. Additionally, they get a push notification when the door unlocks.

How we built it

We used two ESP 32s that connect to each other through the ESP-NOW wireless communication protocol. When the correct code is entered, a command is sent from the keypad module to the door handle module to activate the linear actuator. The linear actuator is implemented by connecting a stepper motor to a bar with teeth using a stepper motor. The bar extends, pushing down the door handle. We also connected an LCD screen to the keypad module to display prompts and the current entry being entered.

Programming the keypad module to receive information from the Blynk mobile app and to send an event-log notification to the Blynk platform allowed us to implement change-of-password and mobile notification when the door is opened.

Challenges we ran into

Getting the ESP-NOW protocol to establish the connection between the two ESPs.
Getting the motor to function properly, i.e. finding the correct power supply and parameters in the code

Accomplishments that we're proud of

Establishing the connections between the ESPs and successfully transferring data between the two
Successfully integrating the Blynk platform's services into our product

What we learned

ESP-NOW
Blynk
ESP 32 embedded development, along with components like keypad, LCD, and stepper motor
Power Electronics

What's next for LockedOut

Implementing face recognition
Adding memory so as to enable the device to preserve user settings between boots
Integrating commercial grade motors and parts to ensure that the unlocking system is robust

Built With

arduinoide
blynk
c++
esp-now
esp32

Submitted to

RoboTech 2025
- Winner Beginner Track - Runner Up

Created by

I wrote a large part of the firmware for the ESP 32s. This included the code to read and logically process the inputs from the keyboard, to display results on the LCD screen, to send data from the keypad module to the door handle module, and to trigger the linear actuator. I was also responsible for assembling the keypad module's circuitry.

Adityan Swaminathan
I integrated the Blynk IoT platform into the firmware of the keypad module. This includes the functionality of sending valid passcodes to the ESP32 through WiFi. Additionally, I was responsible for the functionality of the ESP32 sending notifications to the end user's phone whenever the door was successfully unlocked. Lastly, I was the team's "professional wire cutter," a very crucial role as I assisted in the cutting and stripping of wires utilized in the project's electrical components. My contributions as a professional wire cutter truly "shaped" the project as I meticulously trimmed, stripped, and occasionally accidentally shortened crucial connections.

Akash Sarode
I was the idea creator/project designer, and primarily worked on the stepper-motor based linear actuator and the door-handle module and integration of the door-handle module with the keypad module.

Raj Kothari
Amogh Kondaji