This Arduino code is designed for the Arduino Nano Matter to become a smart door lock that is capable of moving a servo, controlling an LED, and using button input for a passcode. The door lock is compatible with the Matter smart home protocol, and fits nicely within the Matter ecosystem and your smart home. The only requirement is that you have a Thread Border Router for the Arduino Nano Matter to connect to.
After the code is flashed, you will need to set it up. You can use the QR Code link provided in the terminal, or use a manual pairing code. Once paired, (and whenever it turns on/resets after that) the RGB LED will begin to pulse blue. This signifies that it is in the process of connecting to the Thread Border Router that you specificed.
Once connected, the LED will turn off, indicating that the process has finished and that the door lock is ready to be controlled. You can then freely control the door lock either through your Matter smart home, or manually with the buttons. When the door is locked, the LED will be red, and when unlocked, the LED will be green. To unlock the door manually, enter the passcode specified in the code under the buffer variable (1-1-3-2 by default) using the corresponding buttons 1, 2, or 3. To lock the door manually, simply press any combination of incorrect buttons, and the door will lock if it wasn't locked already.
If you hit a wrong button and want to clear your input, simply wait for 5 seconds and all button input will be erased. If this is too long, the inputWaitTime variable can be customized in the code to change the clear time.
Open the repo folder in Arduino IDE. If needed, pin numbers for components such as the RGB LED, servo, and buttons can be changed manually in the Arduino code file. Flash the code onto the Arduino Nano Matter. Once done, in the Serial Monitor (115200 baud), information for pairing the door lock can be found and used with a Matter compatible device.
1x Arduino Nano Matter (or similar board)
1x MG90 Servo (SG90 also works)
3x Push Buttons
1x RGB LED
This code was created for a personal smart door knob project of mine, which is why there are some specific things in the code (like servo rotation angles) due to those working best with locking and unlocking my own personal door knob.