R305 All-in-One Optical Fingerprint Sensor Module – Arduino-Compatible Biometric Reader

SKU: FA2035
Model

R305 (Optical Edition)
Interface

UART (TTL Serial)
Baud Rate

9600 to 115200 bps (Default: 57600)
Supply Voltage

DC 3.6V – 6.0V
Operating Current

< 120mA (Peak: 150mA)
Fingerprint Capacity

256 Templates
Resolution

500 DPI
Matching Speed

< 0.8 Seconds (1:N mode)
Description
The R305 Optical Fingerprint Sensor Module is a professional-grade biometric solution designed for high-security access control and identity verification. This all-in-one module integrates a high-resolution optical sensor, a specialized digital signal processor (DSP), and advanced fingerprint recognition algorithms into a single, compact unit.
The R305 is engineered to handle the entire fingerprint processing workflow internally—from image capturing and feature extraction to template generation and matching. With its built-in flash memory, it can store and manage hundreds of unique fingerprint templates without requiring an external database. Its universal TTL Serial (UART) interface makes it highly compatible with microcontrollers such as Arduino, Raspberry Pi, STM32, and ESP32, providing a reliable and cost-effective biometric entry point for both standalone DIY projects and commercial security systems.
Key Features
  • All-in-One Processing: Onboard DSP performs all complex mathematical calculations for fingerprint matching, offloading the work from your main microcontroller.
  • High-Resolution Imaging: The optical sensor captures clear, detailed fingerprint images for high-accuracy matching and a low false-rejection rate.
  • Large Storage Capacity: Integrated flash memory stores up to 256 individual fingerprint templates directly on the module.
  • User-Friendly Interface: Uses simple UART (Serial) communication; no complex drivers are needed to enroll, search, or delete fingerprints.
  • Multi-Mode Matching: Supports both 1:1 (Verification) and 1:N (Identification) matching modes.
  • Adjustable Security Levels: Users can configure the security threshold (matching confidence level) to suit different environmental requirements.
Usage Instructions
  1. Wiring: Connect VCC to 5V, GND to Ground, TX to your MCU’s RX, and RX to your MCU’s TX.
  2. Enrolling: Use a serial command (or a library like Adafruit Fingerprint) to put the module into “Enroll” mode. Place a finger on the sensor twice to generate and store a template in a specific ID slot (e.g., ID #1).
  3. Searching/Matching: Place a finger on the sensor. The module will compare the scan against its internal database and return the matching ID number via the serial port if a match is found.
  4. Indicators: The sensor window will light up (usually red or blue) when active, indicating it is ready to scan.
  5. Software: For PC testing, use “Fingerprint Test Software” via a USB-to-TTL converter to manage the database visually.
Q: Can I use this sensor with an Arduino?

Yes! The R305 is fully compatible with Arduino. Many open-source libraries are available that allow you to enroll and verify fingerprints with just a few lines of code

Q: Does the module lose stored fingerprints if the power is disconnected?

No. All fingerprint templates are stored in non-volatile onboard flash memory. They will remain saved indefinitely until you manually issue a “Delete” command

Q: Is this module suitable for outdoor use?

The R305 is an optical sensor. While it is durable, it should be protected from direct sunlight (which can interfere with the optical scan) and moisture. For outdoor business applications, we recommend housing it in a weather-resistant enclosure

Q: How do I transfer fingerprint data to a computer?

You can use a USB-to-TTL (UART) adapter to connect the R305 directly to your PC. This allows you to use management software to upload, download, or backup the fingerprint database.

Q: What happens if a finger is wet or dirty?

Optical sensors perform best with clean, dry fingers. Excessive moisture or heavy grease may lower the recognition accuracy. The R305’s security level can be adjusted via software to be more or less “strict” based on your needs

Q: Is the R305 suitable for commercial "Time & Attendance" systems?

Yes. Its fast matching speed (<0.8s) and 256-template capacity make it an excellent core component for small-to-medium business employee logging systems.

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