GROW-R307S Fingerprint Module

Description :

The GROW-R307S is an optical fingerprint sensor module commonly used in access control systems, biometric locks, attendance systems, and embedded electronics projects such as Arduino, ESP32, and Raspberry Pi.

It integrates fingerprint image capture, feature extraction, and fingerprint matching inside a single all-in-one module.

???? Technical Specifications

Sensor

• Type: Optical

• Resolution: 500 DPI

• Capture window: approx. 14 × 18 mm

Power

• Supply voltage: 4.2 V to 6 V DC (typically 5 V)

• Typical operating current: ≤ 75 mA

Communication

• UART (TTL level)

• Default baud rate: 57,600 bps

• Adjustable baud rate: 9,600 – 115,200 bps

• USB version available on some models

Storage

• Capacity: Up to 1000 fingerprints

• Data sizes:

  • Feature file: 256 bytes

  • Template (model): 512 bytes

Performance

• Image acquisition time: < 0.3 s

• Matching time: < 0.2 s

• Matching modes:

  • 1:1 (verify against a known ID)

  • 1:N (search entire database)

• Error rates:

  • FRR (False Reject): ≤ 0.1 %

  • FAR (False Accept): ≤ 0.0001 %

Durability

• Lifetime: Up to 100 million touches

• Static protection: Up to 15 kV

Environment

• Operating temperature: –20 °C to +50 °C

• Dimensions: approx. 52 × 20 × 22 mm

???? Pinout (6-pin UART version)

????️ How It Works

1) Fingerprint Enrollment

• User places finger twice.

• The module:

  1. Captures images

  2. Extracts fingerprint features

  3. Generates a template

  4. Stores it in internal flash memory

2) Fingerprint Recognition

• When a finger is placed:

  • The sensor captures and processes the image

  • Matches it against:

    • A specific ID (1:1), or

    • All stored fingerprints (1:N)

  • Returns:

    • Match success

    • Match failure

    • ID number (if matched)

???? Common Applications

• Biometric door locks

• Access control systems

• Time attendance systems

• Secure boxes and safes

• Arduino / ESP32 / Raspberry Pi projects

• Smart home and IoT systems

✔️ Tips for Use

• Always use a stable 5V power supply.

• Connect UART properly: TX → RX, RX → TX.

• Keep the sensor surface clean.

• If no response: check baud rate settings.

• Protect the module from voltage spikes.