Smart fingerprint cabinet lock 2.0

Project Description:
This module was originally developed for use on cabinets in the elevator lobby outside the front door. Because the elevator lobby is an open area, the security of items stored in the cabinets is not guaranteed. Therefore, a fingerprint electromagnetic lock was developed, which connects to the home's HA smart home control center via ESP32 and can be unlocked in multiple ways.
I personally dislike battery-powered devices because they can run out of power unexpectedly and are too inconvenient. The initial intention of developing this lock was to provide a fingerprint lock that can use mains power and won't have to worry about
running out of power later. Although power outages are rare nowadays, I still included a 12V battery UPS function, so there's no need to worry about the cabinet door not opening during a power outage.
 
Open Source License :
CC-BY-NC-SA 3.0, Creative Commons License - Attribution-NonCommercial-ShareAlike.
CC: Creative Commons license.
BY: Attribution. You must give appropriate attribution, provide a link to this license, and indicate whether modifications were made (to the original work).
SA: Share Alike. If you remix, transform, or create based on this work, you must share and release your contributions under the same license as the original.
NC: Non-Commercial Use Only. You may not use this work for commercial purposes.
 
Project-Related Functions
: Main Functions: Unlocks after successful fingerprint recognition; other unlocking methods from the smart home control center.
Additional Functions: Automatic low-voltage charging of the 12V battery; automatic power-off when fully charged; automatic 12V battery power supply during power outages.
Communication: Control commands can be sent via SOCKET network communication and MQTT.
A 433MHz frequency receiver module has been added, allowing for radio frequency control of unlocking.
MQTT logging is integrated into NODE-RED for unified log management.
A separate control circuit can be set up for each individual electromagnetic lock, providing temporary storage for delivery personnel when not at home.
 
Project Attributes :
This project is being publicly disclosed for the first time and is an original work by the author. This project has not won any awards in other competitions.
 
Project Progress
: Completed .
 
Design Principles
: The fingerprint module and ESP32 module use UART communication. After successful fingerprint recognition, the relay engages, and the electromagnetic lock automatically opens.
The ESP32 connects to the smart home control center via MQTT. Through MQTT communication, it can execute commands such as fingerprint enrollment, deletion, querying, unlocking, and checking the electromagnetic lock status.
It prioritizes mains power when available, automatically switching to 12V battery power during power outages. The ESP32's ADC port monitors the battery level; if the voltage is low, it initiates charging and automatically shuts off when fully charged.
The main control module connects to the fingerprint reader via a network cable (this is only a connection cable and does not transmit data via the network) for UART data communication.
 
Software description:
The software source code is shared in the attachment .
 
Physical demonstration :
 
Main control module:
Fingerprint recognition module
, electromagnetic lock, 12V, rated current 0.4A. The number of modules that can be connected depends on the relay and power supply. Because my cabinet only has 5 doors, I connected 5.
 
 
Other
demonstration videos: [2024 Spark Program] Fingerprint Smart Lock 2.0_Bilibili_bilibili
Project Attachment: Entries participating in the event must upload the relevant program attachments to the open-source platform or personal code storage cloud. The maximum upload size for attachments is 50MB (please do not upload to the LCSC workspace, as there are limitations).