Introduction
This tutorial details the AS608 module, its functions, and the method to build a simple project using the AS608 and an Arduino.
Optical Fingerprint Reader Sensor Module - AS608
The AS608 module is used to scan fingerprints and send the data to a microcontroller via serial communication. The module can store up to 127 individual fingerprints.
Pin Out
The AS608 has four useful pins.
| Pin | Description |
|---|---|
| V+ | Module Power Supply (3.3VDC) |
| TX | Serial Transmitter |
| RX | Serial Receiver |
| GND | Ground |
How it Works
The AS608 has a built-in fingerprint scanner and memory circuit. The scanner takes an image of the finger print using light reflections. Depending on the program, the image captured is either stored in the memory or compare to previous image stored in the memory. The AS608 communicates to the microcontroller using serial monitor to provide actions on the image captured.
Project - Arduino Fingerprint Scanner
After learning about the AS608 module and how it works, it is now time to build a project using the module. Our project will scan fingerprint, save it to memory and then check if the fingerprint will match.
Components
- Arduino Uno Board (1 pc.)
- Optical Fingerprint Reader Sensor Module – AS608 (1 pc.)
- Jumper Wires
Wiring Diagram
The AS608 module pins are connected to the Arduino Uno board as follows:
| Module Pin | UNO Board Pin |
|---|---|
| V+ | 3.3V |
| TX | 2 |
| RX | 3 |
| GND | GND |
Code
The library for this module must first be downloaded and can be accessed here; Fingerprint Sensor Library
Once the library is installed, the program code can be uploaded.
Program 1: Enrolling Fingerprint
#include <Adafruit_Fingerprint.h>
SoftwareSerial mySerial(2, 3); // TX/RX
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);
uint8_t id;
void setup()
{
Serial.begin(9600);
while (!Serial); // For Yun/Leo/Micro/Zero/...
delay(100);
Serial.println("\n\nAdafruit Fingerprint sensor enrollment");
// set the data rate for the sensor serial port
finger.begin(57600);
if (finger.verifyPassword()) {
Serial.println("Found fingerprint sensor!");
} else {
Serial.println("Did not find fingerprint sensor :(");
while (1) { delay(1); }
}
}
uint8_t readnumber(void) {
uint8_t num = 0;
while (num == 0) {
while (! Serial.available());
num = Serial.parseInt();
}
return num;
}
void loop() // run over and over again
{
Serial.println("Ready to enroll a fingerprint!");
Serial.println("Please type in the ID # (from 1 to 127) you want to save this finger as...");
id = readnumber();
if (id == 0) {// ID #0 not allowed, try again!
return;
}
Serial.print("Enrolling ID #");
Serial.println(id);
while (! getFingerprintEnroll() );
}
uint8_t getFingerprintEnroll() {
int p = -1;
Serial.print("Waiting for valid finger to enroll as #"); Serial.println(id);
while (p != FINGERPRINT_OK) {
p = finger.getImage();
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image taken");
break;
case FINGERPRINT_NOFINGER:
break;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
break;
case FINGERPRINT_IMAGEFAIL:
Serial.println("Imaging error");
break;
default:
Serial.println("Unknown error");
break;
}
}
// OK success!
p = finger.image2Tz(1);
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image converted");
break;
case FINGERPRINT_IMAGEMESS:
Serial.println("Image too messy");
return p;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
return p;
case FINGERPRINT_FEATUREFAIL:
Serial.println("Could not find fingerprint features");
return p;
case FINGERPRINT_INVALIDIMAGE:
Serial.println("Could not find fingerprint features");
return p;
default:
Serial.println("Unknown error");
return p;
}
Serial.println("Remove finger");
delay(2000);
p = 0;
while (p != FINGERPRINT_NOFINGER) {
p = finger.getImage();
}
Serial.print("ID "); Serial.println(id);
p = -1;
Serial.println("Place same finger again");
while (p != FINGERPRINT_OK) {
p = finger.getImage();
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image taken");
break;
case FINGERPRINT_NOFINGER:
break;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
break;
case FINGERPRINT_IMAGEFAIL:
Serial.println("Imaging error");
break;
default:
Serial.println("Unknown error");
break;
}
}
// OK success!
p = finger.image2Tz(2);
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image converted");
break;
case FINGERPRINT_IMAGEMESS:
Serial.println("Image too messy");
return p;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
return p;
case FINGERPRINT_FEATUREFAIL:
Serial.println("Could not find fingerprint features");
return p;
case FINGERPRINT_INVALIDIMAGE:
Serial.println("Could not find fingerprint features");
return p;
default:
Serial.println("Unknown error");
return p;
}
// OK converted!
Serial.print("Creating model for #"); Serial.println(id);
p = finger.createModel();
if (p == FINGERPRINT_OK) {
Serial.println("Prints matched!");
} else if (p == FINGERPRINT_PACKETRECIEVEERR) {
Serial.println("Communication error");
return p;
} else if (p == FINGERPRINT_ENROLLMISMATCH) {
Serial.println("Fingerprints did not match");
return p;
} else {
Serial.println("Unknown error");
return p;
}
Serial.print("ID "); Serial.println(id);
p = finger.storeModel(id);
if (p == FINGERPRINT_OK) {
Serial.println("Stored!");
} else if (p == FINGERPRINT_PACKETRECIEVEERR) {
Serial.println("Communication error");
return p;
} else if (p == FINGERPRINT_BADLOCATION) {
Serial.println("Could not store in that location");
return p;
} else if (p == FINGERPRINT_FLASHERR) {
Serial.println("Error writing to flash");
return p;
} else {
Serial.println("Unknown error");
return p;
}
}
Program 2: Fingerprint Testing and Verification
#include <Adafruit_Fingerprint.h>
volatile int finger_status = -1;
SoftwareSerial mySerial(2, 3); // TX/RX on fingerprint sensor
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);
void setup()
{
Serial.begin(9600);
while (!Serial); // For Yun/Leo/Micro/Zero/...
delay(100);
Serial.println("\n\nAdafruit finger detect test");
// set the data rate for the sensor serial port
finger.begin(57600);
if (finger.verifyPassword()) {
Serial.println("Found fingerprint sensor!");
} else {
Serial.println("Did not find fingerprint sensor :(");
while (1) { delay(1); }
}
finger.getTemplateCount();
Serial.print("Sensor contains "); Serial.print(finger.templateCount); Serial.println(" templates");
Serial.println("Waiting for valid finger...");
}
void loop() // run over and over again
{
finger_status = getFingerprintIDez();
if (finger_status!=-1 and finger_status!=-2){
Serial.print("Match");
} else{
if (finger_status==-2){
for (int ii=0;ii<5;ii++){
Serial.print("Not Match");
}
}
}
delay(50); //don't ned to run this at full speed.
}
// returns -1 if failed, otherwise returns ID #
int getFingerprintIDez() {
uint8_t p = finger.getImage();
if (p!=2){
Serial.println(p);
}
if (p != FINGERPRINT_OK) return -1;
p = finger.image2Tz();
if (p!=2){
Serial.println(p);
}
if (p != FINGERPRINT_OK) return -1;
p = finger.fingerFastSearch();
if (p != FINGERPRINT_OK) return -2;
// found a match!
Serial.print("Found ID #"); Serial.print(finger.fingerID);
Serial.print(" with confidence of "); Serial.println(finger.confidence);
return finger.fingerID;
}
Project Test
Wire the components to the Arduino as demonstrated in the wiring diagram. Connect the Arduino to a PC and upload the program.
Fingerprint Enrollment:
For the fingerprint enrollment, open the Serial Monitor in the Arduino IDE. A prompt appears to select a number from 1-127; wherein the fingerprint data will be stored. The maximum number of fingerprints capable of being stored is 127. If a value is allocated more than once, the latest data will be stored.
Fingerprint Testing/Verification:
Open the Serial Monitor in the Arduino IDE and place a finger to the scanner. If this fingerprint was previously registered, the serial monitor will show the ID value (1-127) the print correlates with. If the finger presented has not been previously registered, the module will indicate so.
