Optical fingerprint sensor module, R307S, 3.3-5V

R307S module, compatible with Arduino and other development boards, as well as directly with PC via USB UART interface. This is a biometric sensor, designed for accurate and fast fingerprint identification and verification. It uses an "All-in-One" architecture, combining an optical sensor, a DSP processor and integrated FLASH memory for storing fingerprint templates.

This model supports both UART TTL interface and USB 2.0 connectivity, being directly compatible with 3.3V and 5V microcontrollers (such as Arduino or ESP32), but also with PCs (via MAX232 or USB-Serial adapter). The module can be configured to operate in 1:1 (verification) or 1:N (identification) mode, making it ideal for access control applications, electronic time and attendance, smart locks or embedded security solutions.

The R307S variant of the module allows the storage of up to 300 fingerprints.

The module includes finger presence detection and offers fast image processing with 500 DPI resolution. The dedicated "3.3V" pad can be shorted to allow direct 3.3V power supply (instead of 5V), providing flexibility depending on the platform used.

Normally the module operates at a voltage of 3.3V but the use of an integrated voltage regulator allows use at 5VDC. It comes directly compatible with 5V from the factory. For use at 3.3V it is necessary to short the pads marked 3.3 on the PCB. This applies both to the supply voltage on pin 1 and to the supply voltage on pin 6 which detects the presence of the finger.

The presence of the finger on the scanner causes a HIGH level signal to be transmitted on pin 5.

Specifications:

Supported interfaces: UART TTL and USB 2.0

Supply voltage: 3.3-5V (3.3V pad for direct 3.3V power supply)

Current consumption: 50 mA typical, max. 80 mA

Capture speed: < 0.3 sec

Verification speed: 0.2 sec

Scanning speed: 0.3 sec

Sensor resolution: 500 DPI

Storage capacity: up to 300 fingerprints

Character file size: 256 bytes

Template file size: 512 bytes

False Acceptance Rate (FAR): ≤0.0001%

False Rejection Rate (FRR): ≤0.1%

Operating temperature: -20°C ~ +50°C

Dimensions: 46 x 21 x 23.5mm

Pinout:

Main interface:

Pin 1 and 6 can be connected to 3.3V or 5V. For 5V remove the short on pad 3.3! For 3.3V short pad 3.3! Incorrect use will damage the module!

USB interface:

Use:

Uses the UART (Tx/Rx) interface on the microcontroller. For 3.3V, short the "3.3V" pad.

Communicate via UART commands (ex: GenImg, Img2Tz, Store, Search, ReadSysPara) to capture, process and store fingerprints or use a development board with a library dedicated to this module.

Example of use with ESP32:

For use, we use the Adafruit Fingerprint Sensor Library (also compatible with ESP32).

Connection according to the image:

GPIO16 (ESP32) → RXD (pin 4 R307)

GPIO17 (ESP32) → TXD (pin 3 R307)

VIN → +5V

GND → GND

ESP32 code - compiled with Arduino IDE:

__________________________________________________________________

#include

#include

// Create a dedicated hardware serial port for the sensor

HardwareSerial fingerSerial(2); // UART2 on ESP32 (GPIO17 = TX, GPIO16 = RX)

Adafruit_Fingerprint finger = Adafruit_Fingerprint(&fingerSerial);

void setup() {

Serial.begin(115200);

delay(1000);

// Initialize UART2

fingerSerial.begin(57600, SERIAL_8N1, 16, 17); // RX=16, TX=17

Serial.println("Init fingerprint sensor R307...");

finger.begin(57600);

if ( finger.verifyPassword ()) {

Serial.println("Sensor detected!");

} else {

Serial.println("Cannot communicate with sensor.");

while (1) delay(1);

}

}

void loop() {

Serial.println("Waiting for fingerprint...");

if (getFingerprintID() == FINGERPRINT_OK) {

Serial.println("Fingerprint recognized!");

} else {

Serial.println("Unknown fingerprint.");

}

delay(3000);

}

uint8_t getFingerprintID() {

uint8_t p = finger.getImage ();

if (p != FINGERPRINT_OK) return p;

p = finger.image2Tz ();

if (p != FINGERPRINT_OK) return p;

p = finger.fingerSearch ();

if (p == FINGERPRINT_OK) {

Serial.print("ID found: "); Serial.println(finger.fingerID);

Serial.print("Trust: "); Serial.println( finger.confidence );

}

return p;

}

___________________________________________________

Content:

1 x Optical Fingerprint Sensor Module R307S

1 x Connection cable (6 pins)