Fingerprint sensors are a type of biometric technology that has become increasingly popular for security and authentication purposes in recent years. They offer many advantages, such as improved security, convenience, and ease of use, but also have some limitations to consider, such as the potential for false positives and negatives, security risks, and privacy concerns. The R307 and R305 fingerprint sensors are two common types available in the market, with similar features such as optical sensors, high resolution, and the ability to store up to 1000 fingerprint templates. To use the R307 sensor with ESP32 using Arduino IDE, you can follow the steps outlined below, including connecting the sensor to the ESP32, including the required libraries, defining the serial communication port, initializing the sensor, and performing fingerprint operations.
What is Finger Print Sensor?
A fingerprint sensor is a biometric security technology that is used to authenticate or verify the identity of an individual based on their unique fingerprint. It is designed to capture a digital image of a person's fingerprint and compare it to a stored database of fingerprints to determine if there is a match.
Fingerprint sensors are commonly found in smartphones, laptops, and other electronic devices as a means of secure authentication. They can also be used in security systems, access control systems, and other applications where identification and verification are necessary. The technology behind fingerprint sensors has advanced in recent years, allowing for more accurate and reliable identification.
How Fingerprint Sensor works?
Fingerprint sensors use a variety of technologies to capture and analyze a person's fingerprint. The most common type of fingerprint sensor is the capacitive sensor, which uses a grid of tiny capacitor plates to detect the ridges and valleys on a person's fingertip.
Here's how a typical capacitive fingerprint sensor works:
The user places their finger on a small sensor pad.
The sensor pad sends a small electrical current through the finger, which is picked up by the capacitor plates underneath.
The ridges and valleys of the fingerprint create variations in the electrical field, causing the capacitance to change at different points across the sensor pad.
The sensor measures these changes in capacitance and converts them into a digital image of the fingerprint.
The image is then processed by a software algorithm that identifies the unique patterns and features of the fingerprint.
The algorithm compares the fingerprint image to a database of stored fingerprints to determine if there is a match.
If there is a match, the fingerprint sensor sends a signal to unlock the device or grant access to a secure area. If there is no match, the device remains locked or access is denied.
Advantages of using Fingerprint Sensor
Fingerprint sensors offer several advantages over traditional methods of authentication or identification, including:
- Security: Fingerprint sensors are highly secure because each person's fingerprint is unique and cannot be replicated. This makes it difficult for unauthorized individuals to gain access to a device or secure area.
- Convenience: Fingerprint sensors are fast and easy to use, eliminating the need for passwords or PINs that can be forgotten or stolen. Users simply need to place their finger on the sensor to authenticate their identity.
- Accuracy: Fingerprint sensors have a high level of accuracy and can reliably identify individuals even in low light or other challenging conditions.
- Integration: Fingerprint sensors can be integrated into a wide range of devices, including smartphones, laptops, and security systems, making them a versatile and widely used technology.
- Cost-effective: Fingerprint sensors are relatively low-cost and can be manufactured at scale, making them an affordable option for device manufacturers and end-users.
- Personalization: Fingerprint sensors allow for personalized user experiences, such as customizing settings or preferences for different users based on their unique fingerprint.
- Accessibility: Fingerprint sensors provide accessibility benefits for individuals with disabilities, who may have difficulty using traditional authentication methods such as typing in a password.
- Remote Access: Fingerprint sensors can enable remote access to devices or systems, allowing users to securely access their data or control their devices from anywhere.
- Non-Transferrable: Fingerprints cannot be transferred from one person to another, unlike passwords or other forms of authentication that can be shared or stolen.
- Hygiene: Fingerprint sensors are more hygienic than traditional methods of authentication such as keypads, which can harbor bacteria and viruses. Fingerprint sensors can be easily wiped clean and do not require physical contact with the device.
The Fingerprint Sensors offer a range of benefits that make them a popular and widely used technology for authentication and identification. From security and convenience to accessibility and hygiene, fingerprint sensors provide a reliable and user-friendly way to protect personal information and secure devices and systems.
Limitations of Fingerprint Sensor
While fingerprint sensors offer many advantages, there are also some limitations to consider:
- False negatives: Fingerprint sensors may fail to recognize a valid fingerprint if the finger is wet, dirty, or damaged, leading to false negatives and a need for re-authentication.
- False positives: Fingerprint sensors may also mistakenly recognize an unauthorized user as the rightful owner if the pattern on their finger is similar enough to the authorized user's fingerprint, leading to false positives.
- Security Risks: In some cases, fingerprints can be lifted from a surface and used to replicate an authorized user's fingerprint, potentially leading to security breaches or identity theft.
- Compatibility: Fingerprint sensors may not be compatible with all devices or operating systems, which can limit their usefulness in certain contexts.
- Reliability: Fingerprint sensors may not be reliable over time due to wear and tear, and may require maintenance or replacement to maintain accuracy.
- Privacy concerns: There are concerns about the privacy implications of collecting and storing biometric data, such as fingerprints, and the potential for this data to be misused or compromised.
Overall, while fingerprint sensors offer many advantages, it is important to be aware of these limitations and to weigh the potential benefits against the risks before deciding to use them.
Features of R 307 and R 305 Fingerprint Sensors
The R307 and R305 are two common types of fingerprint sensors available in the market. Here are some features of each sensor:
R307 Fingerprint Sensor:
- Optical sensor
- High-resolution (500dpi) fingerprint image capture
- Wide operating temperature range (-20°C to +60°C)
- Low power consumption
- Interface options include UART, USB, and TTL
- Can store up to 1000 fingerprint templates
- 1:N identification and 1:1 verification modes
R305 Fingerprint Sensor:
- Optical sensor
- 500dpi resolution
- Wide operating voltage range (3.3V to 6V)
- Low power consumption
- Interface options include UART, USB, and TTL
- Can store up to 500 fingerprint templates
- 1:N identification and 1:1 verification modes
Both sensors are similar in terms of their features, with the main differences being their operating temperature range and operating voltage range. Ultimately, the choice between the two sensors may come down to factors such as cost, compatibility with existing hardware, and specific application requirements.
How to use R 307 sensor with ESP32 using Arduino IDE
Here are the steps to use the R307 fingerprint sensor with ESP32 using Arduino IDE:
- Connect the R307 fingerprint sensor to the ESP32 using the appropriate interface (UART, USB, or TTL). Make sure to connect the sensor's power supply and ground to the ESP32 as well.
- Open the Arduino IDE and create a new sketch.
- Include the required libraries for the R307 fingerprint sensor in your sketch. You can download the R307 library from the internet or create your own library.
- Define the serial communication port that the sensor is connected to in your sketch. For example, if you are using UART, you can define the port as follows:
- Use the R307 library to perform fingerprint operations such as enrolling, verifying, and deleting fingerprints. For example, to enroll a new fingerprint, you can use the following code:
- Upload the sketch to the ESP32 and test the fingerprint sensor. Make sure to open the serial monitor in the Arduino IDE to view the output from the ESP32 and the fingerprint sensor.
These are the basic steps to use the R307 fingerprint sensor with ESP32 using Arduino IDE. Keep in mind that there may be variations depending on the specific sensor and hardware configuration used.
Hardware interface of FingerPrint Sensor R 307 with ESP32
Example code to use FingerPrint Sensor R 307 with ESP32 using Arduino IDE
#include <Adafruit_Fingerprint.h>
#if (defined(__AVR__) || defined(ESP8266)) && !defined(__AVR_ATmega2560__)
// For UNO and others without hardware serial, we must use software serial...
// pin #2 is IN from sensor (GREEN wire)
// pin #3 is OUT from arduino (WHITE wire)
// Set up the serial port to use softwareserial..
SoftwareSerial mySerial(2, 3);
#else
// On Leonardo/M0/etc, others with hardware serial, use hardware serial!
// #0 is green wire, #1 is white
#define mySerial Serial2 //Use RX2 and TX2 pins of ESP32 board
#endif
bool fConfig = false;
uint8_t id;
uint8_t rBuff;
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);
uint8_t readnumber(void) {
uint8_t num = 0;
while (num == 0) {
while (! Serial.available());
num = Serial.parseInt();
}
return num;
}
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);
delay(5);
if (finger.verifyPassword()) {
Serial.println("Found fingerprint sensor!");
} else {
Serial.println("Did not find fingerprint sensor :(");
while (1) { delay(1); }
}
Serial.println(F("Reading sensor parameters"));
finger.getParameters();
Serial.print(F("Status: 0x")); Serial.println(finger.status_reg, HEX);
Serial.print(F("Sys ID: 0x")); Serial.println(finger.system_id, HEX);
Serial.print(F("Capacity: ")); Serial.println(finger.capacity);
Serial.print(F("Security level: ")); Serial.println(finger.security_level);
Serial.print(F("Device address: ")); Serial.println(finger.device_addr, HEX);
Serial.print(F("Packet len: ")); Serial.println(finger.packet_len);
Serial.print(F("Baud rate: ")); Serial.println(finger.baud_rate);
finger.getTemplateCount();
if (finger.templateCount == 0) {
Serial.print("Sensor doesn't contain any fingerprint data. Please run the 'enroll' example.");
}
else {
Serial.println("Waiting for valid finger...");
Serial.print("Sensor contains "); Serial.print(finger.templateCount); Serial.println(" templates");
}
}
void loop() // run over and over again
{
if (Serial.available())
{
rBuff = Serial.read();
if ( rBuff == 'C' )
{
fConfig = true;
}
else if ( rBuff == 'D' )
{
Serial.println("Please type in the ID # (from 1 to 127) you want to delete...");
id = readnumber();
deleteFingerprint(id);
}
}
if (fConfig)
{
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 == 130) // exit enroll id mode
{
Serial.print("exit enroll#");
fConfig = false;
}
else
{
Serial.print("Enrolling ID #");
Serial.println(id);
while (!getFingerprintEnroll() );
}
}
else
{
getFingerprintID();
}
delay(50); //don't ned to run this at full speed.
}
uint8_t deleteFingerprint(uint8_t id) {
uint8_t p = -1;
p = finger.deleteModel(id);
if (p == FINGERPRINT_OK) {
Serial.println("Deleted!");
} else if (p == FINGERPRINT_PACKETRECIEVEERR) {
Serial.println("Communication error");
} else if (p == FINGERPRINT_BADLOCATION) {
Serial.println("Could not delete in that location");
} else if (p == FINGERPRINT_FLASHERR) {
Serial.println("Error writing to flash");
} else {
Serial.print("Unknown error: 0x"); Serial.println(p, HEX);
}
return p;
}
uint8_t getFingerprintID() {
uint8_t p = finger.getImage();
switch (p) {
case FINGERPRINT_OK:
Serial.println("Image taken");
break;
case FINGERPRINT_NOFINGER:
Serial.println("No finger detected");
return p;
case FINGERPRINT_PACKETRECIEVEERR:
Serial.println("Communication error");
return p;
case FINGERPRINT_IMAGEFAIL:
Serial.println("Imaging error");
return p;
default:
Serial.println("Unknown error");
return p;
}
// OK success!
p = finger.image2Tz();
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!
p = finger.fingerSearch();
if (p == FINGERPRINT_OK) {
Serial.println("Found a print match!");
} else if (p == FINGERPRINT_PACKETRECIEVEERR) {
Serial.println("Communication error");
return p;
} else if (p == FINGERPRINT_NOTFOUND) {
Serial.println("Did not find a match");
return p;
} else {
Serial.println("Unknown error");
return p;
}
// found a match!
Serial.print("Found ID #"); Serial.print(finger.fingerID);
Serial.print(" with confidence of "); Serial.println(finger.confidence);
return finger.fingerID;
}
// returns -1 if failed, otherwise returns ID #
int getFingerprintIDez() {
uint8_t p = finger.getImage();
if (p != FINGERPRINT_OK) return -1;
p = finger.image2Tz();
if (p != FINGERPRINT_OK) return -1;
p = finger.fingerFastSearch();
if (p != FINGERPRINT_OK) return -1;
// found a match!
Serial.print("Found ID #"); Serial.print(finger.fingerID);
Serial.print(" with confidence of "); Serial.println(finger.confidence);
return finger.fingerID;
}
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:
Serial.println(".");
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:
Serial.print(".");
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;
}
return true;
}