Optical Fingerprint Sensor Module (AS608)

Key Features

• All-in-One System: Integrates an optical sensor and a high-speed DSP.
• Onboard Storage: Can store anywhere from 162 (AS608) to over 1000 (FPM10A) different fingerprint templates.
• Simple UART Interface: Connects to your Arduino using only two wires (TX and RX) for serial communication.
• Adjustable Security: You can adjust the security level, which changes how strict the matching algorithm is.
• Easy to Program: Works perfectly with the “Adafruit Fingerprint Sensor Library” in the Arduino IDE.

Technical Specifications

How to Use & Wiring

The module typically comes with a 6-pin cable.

• VCC (Red): Connect to 5V on your Arduino.
• GND (Black): Connect to GND.
• TX (Yellow/Green): Connect to your Arduino’s SoftwareSerial RX pin (e.g., Pin 2).
• RX (White/Blue): Connect to your Arduino’s SoftwareSerial TX pin (e.g., Pin 3).

CRITICAL WARNING – 5V ARDUINO (e.g., UNO)

This sensor uses 3.3V logic.

• Connecting the 5V Arduino’s TX pin directly to the sensor’s RX pin can damage the sensor.
• You must use a logic level shifter or a simple voltage divider (e.g., 1K & 2K resistors) on the line from the Arduino TX to the sensor RX to safely step the voltage down from 5V to ~3.3V.
• The sensor’s 3.3V TX pin will usually work fine with the Arduino’s RX pin, as 3.3V is high enough to be read as a “HIGH” signal.