Security has always been the most concerned issue for mankind. In the past, we protected valuables by keeping them in dungeons, and now we \'ve moved from protecting them to protecting data through layer-by-layer encryption software. In any case, make sure the well Being our personal belongings has always been our top priority. Our home is the best place to store personal belongings. How about the safety of our home? There is no doubt that our door locks play an important role in protecting the safety of our families. Thanks to technology, home security today involves a wide range of software and hardware, including web- Security services, biometric and personal devices based on integrated security levels. One of the biggest advances in digital technology The introduction of biometric technology into the field of security is a technological era. Biometric door locks are now common with increased safety levels and ensure the protection of our door locks. But there are two things that prevent the use of biometric locks. One is the cost of a lock that could start at $300. The other is the lack of remote access. So, let\'s add some flavor of the internet of things to make the biometric door lock more spicy. So to ensure security and remote access, we wanted to come up with a new way to connect the door lock to a personal device. Let\'s think about our phones and they have the ability to control our smart door locks with MQTT and available protocols. So why don\'t we add an extra biometric firewall? Yes, that\'s what we have to do. Almost all phones are now equipped with fingerprint sensors. We use them to verify the biological features of the authorized person. Therefore, it can overcome the shortcomings of existing smart door locks by increasing the security level. In essence, we will build an intelligent remote-controlled door lock with additional biometric security. Since almost all smartphones are equipped with fingerprint sensors, we are using these sensors to verify identity. The data read from the fingerprint sensor is compared to the real fingerprint stored in the device using the mobile app and determines whether the person is authorized. The verified data is sent from the mobile device to the appropriate cloud database from which the smart door lock system retrieves the data. If the person who authorized the smart door lock will unlock it, it will not unlock it if there is no authorization. These are the hardware components we use when building a project, and NodeMCU is an open source IoT platform. It includes firmware running on ESP8266 Wi- Fi SoC from Espressif system and ESP-based-12 module. In this project, the NodeMCU forms the brain of the smart door lock. NodeMCU retrieves data from the cloud database and relays on/off according to the data. The electric door lock module works at 12 V, locks when the power is off, and unlocks when the power is on. It is the physical part of the smart door lock. A relay is a switching device that is used to isolate or change the state of the circuit from one state to another. The 12V power supply is provided to the lock module using the relay according to the data provided by NodeMCUGather, collecting all necessary components. Then weld them correctly according to the given connection mode. I used a micro welding station to control the temperature to avoid damaging the NodeMCU while welding. Be careful when welding, do not damage the MCU, because the high temperature may damage the ICs. We have collected all the components, connected them correctly, and connected the code with them. It\'s time to put them in a fence. The 3D design is made using Fusion 360 and printed in EazyFab. Design documents are attached here. We use the 12V 1A power supply to power the NodeMCU as well as the Power lock module. Since the NodeMCU may damage the MCU, it cannot withstand direct 12v power supply for a long time. I use a 12v power supply just for a prototype. When building a product, be sure to use a 5v power supply to achieve the perfect work of the circuit. Software components consisting of mobile applications are used to scan fingerprints and verify fingerprints and authorize them to individuals. Once the fingerprint is verified, the unlocked key is posted to firebase real-time database. Apply for Kodular. Attach a screenshot of the design and code block. Design the application and code block as shown in the figure to give it life. If you are not interested in building the app, download it from here. Firebase is a mobile and web application development platform. Firebase lets developers focus on creating a great user experience. You don\'t need to manage the server. You don\'t need to write api. Firebase is your server, your API and your data storage, all of which are generic and you can modify it according to most requirements. In our project, we use Firebase real- The time database can publish and retrieve data instantly, so there is no time delay. When designing a mobile app, we need to populate something called the Firebase URL. If you would like to learn more about setting up Firebase, please read the detailed guide here. Now is the time to give life to smart locks. The code for the NodeMCU is developed in C and uploaded using the Arduino IDE. Download the Firebase extension library for NodeMCU from here and add it to the Arduino IDE. Now, download the code from this repository and replace the Firebase URL and Firebase Auth with your code. Then upload the code using the Arduino IDE and verify the work. It\'s time to watch the work. Open the mobile app, click the lock button to verify your identity and open the door. 1. Low cost all components used in this project are very cheap and the net cost of the product is less than $10. 2. Fast unlock the fingerprint sensor on the phone is very fast because firebase is a real Time database running very fast The unlock process is going to be so fast, just like less than 0. 5s3. The Android application provides an encryption algorithm to ensure the security of data transmission, thus making the locklayer security. 4. By sharing the Android app and firebase credentials, multiple people have access to the same door. 5. This door lock can replace any lock. As long as this is used instead of the locking mechanism, it will become a smart door. In the upcoming update we want to include features like you help us? Because your small donation will help us to turn the project into a product with a higher level of security. Your donation is welcome. PayPal ID: Email: nekiary 07 @ gmail.