Fingerprint Sensor Not Detected

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n1shnn
 
Posts: 5
Joined: Wed Feb 23, 2022 8:10 pm

Fingerprint Sensor Not Detected

Post by n1shnn »

I connected the TX wire (green wire) connected to pin 3 and RX wire (white wire) connected to pin 2. The Power wire (red wire) is connected to 5V and the GND wire (black wire) is connected to GND on the Arduino. I am using Arduino UNO and the Adafruit Fingerprint sensor Product 751. I have tried using multiple different pins and have switched the TX and RX wires. I have confirmed that the connections are good using a multimeter and have even re-soldered the RX and TX wires to make sure it wasn't a connectivity issue. The fingerprint sensor's LED lights up but when I open the Serial Monitor and it runs the "fingertest", it always shows "Did not find fingerprint sensor : (". I have looked at many other forums and tried to change the code to SoftwareSerial myserial(8,3); however, it still does not detect the fingerprint sensor. Can someone explain why this might be happening and how I can fix it? Is it an issue with the fingerprint sensor itself?

code:

Code: Select all

#include <Adafruit_Fingerprint.h>
#include <SoftwareSerial.h>
int getFingerprintIDez();
// pin #2 is IN from sensor (GREEN wire)
// pin #3 is OUT from arduino  (WHITE wire)
SoftwareSerial mySerial(2, 3); // 
Adafruit_Fingerprint finger = Adafruit_Fingerprint(&mySerial);
void setup()
{
  Serial.begin(9600);
  Serial.println("fingertest");
  pinMode(13, OUTPUT);
  digitalWrite(13, LOW);
  // set the data rate for the sensor serial port
  finger.begin(9600);
  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
{
  getFingerprintIDez();
  delay(50);            //don’t ned to run this at full speed.
}
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.fingerFastSearch();
  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);
}
// 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);
  digitalWrite(13, HIGH);
  delay(3000);
  digitalWrite(13, LOW);
  return finger.fingerID;
}
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adafruit_support_carter
 
Posts: 29168
Joined: Tue Nov 29, 2016 2:45 pm

Re: Fingerprint Sensor Not Detected

Post by adafruit_support_carter »

Please remove the relay board and solenoid. Connect just the fingerprint sensor to the UNO. Post another higher res photo showing how everything is connected.

Compare your sensor's wiring harness to the information here:
https://learn.adafruit.com/adafruit-opt ... th-arduino
For yours, does it appear that white is corresponding to sensor RX and green to sensor TX?

User avatar
adafruit_support_carter
 
Posts: 29168
Joined: Tue Nov 29, 2016 2:45 pm

Re: Fingerprint Sensor Not Detected

Post by adafruit_support_carter »

Cross posted:
viewtopic.php?f=19&t=188786

Moving conversation to that thread.

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