Wednesday, December 12, 2018

Fingerprint Sensor with an Arduino or an ESP


There are different bio metric sensors on the market. They are commonly used to access a private area. Let it be a door, a safe or the privacy of your smartphone. The most known is the fingerprint sensor. A commercial bio metric sensor costs quite a fortune. But there is a cheap alternative for the Maker community. A fingerprint sensor for around 20€.
But how to save and identify a fingerprint with an Arduino? Well, you don't need to. The sensor does all the work. You only have to tell the sensor what to do.


If you're lucky, you'll get a color coded connection cable. If you aren't, you will get one where at least the GND line is marked. It should be in one of the corners of the cable. From there you can find the rest. The order would be: GND - RX - TX - 5V. And two pins without a connection.
 You have to connect GND to GND, VCC to 5V, TX to RX and RX to TX. But if you want to use the serial monitor to watch your results, you shouldn't use the Rx and Tx on the Arduino side, because it will conflict with the USB-port. You can use the Software Serial library and use pin 2 and 3.

The sensor, I received, was only 5V compatible. So if you want to use it with a NodeMcu or any other ESP, you have to add +5V to power the sensor.


There is no need to reinvent the wheel. If you search for "fingerprint" in the library manager of your Arduino IDE, you'll probably find two libraries. I used the one from Adafruit. It's equipped with examples for a quick start.
With the example sketch "enroll", you can start saving fingerprints to the sensor.
To test it, use the sketch "fingerprint". You'll get the found ID in the internal database of the sensor and the probability for a positive match. With that, you have all you'll need to build your own access control.




Fingerprint Sensor
Arduino Uno


Fingerprint Recognition Module --
Wholesale Arduino Compatible SCM --
More Electronics (EU Warehouse) --

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  1. This comment has been removed by a blog administrator.

  2. With pin are you using for the esp8266?

    1. Since you use the Software Serial library, you can choose which pins you are using. I've used pin D2 and D3

  3. plz send me software u r using and step by step directions to use it and match my ardiuno uno with fingerprint module

  4. can you explain why you don't use the other two pins plz

    1. Because they aren't connected to anything on the fingerprint sensor.

  5. Hallo, hätte eine Frage bezüglich des Fingerprint Sensors. Ich möchte sobald der finger erkannt wurde einen Ausgang mit schalten worüber ich ein Relai zum anziehen bringen möchte um mein türöffner damit zu steuern. Gibt es dafür eine schnelle Lösung mit einem Code?
    Danke im voraus
    MFG Marius

  6. I've done the connections as mentioned as I'm using ESP8266 so I used D2 and D3. But I'm getting "Did not find fingerprint sensor" on the serial output.can anyone help me with this

  7. Am using arduino board to build a fingerprint door lock system. But am not using adafruit scanner. I need help please. I need the codes that can work on my arduino IDE. My project mini defense is this Wednesday. Thanks

  8. If I want to connect with an 8-pin esp8266, how can I connect to the fingerprint sensor?

  9. Please send Wires connection of finger print sensor