Ribin-Baby / fplib-GT521Fx2

This is a Python3 library for sparkfun GT-521F32 and GT-521F52 fingerprint sensors 👍. A MicroPython version is also available in this Repo.

> Python Library for GT-521Fx2 fingerprint sensor module

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• we have support for both python3 and MicroPython.
• Tested python-version: [ "3.6.9" ]

>> introduction to GT-521Fx2

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Our code is specially developed for GT-521F32 and GT-521F52 series of sparkfun fingerprint sensors.

This fingerprint scanner has the ability to:

• Enroll a Fingerprint
• Identify a Fingerprint
• Capable of 360° Recognition

While the input voltage is between 3.3V and 6V, the UART's logic level is only 3.3V. You will need a logic level converter or voltage divider to safely communicate with a 5V device.

Pinout:

• A Quick testing tool by sparkfun for windows is available to download from here.

Fig.1 - SDK_DEMO.exe quick testing tool for windows.

• The SDK_DEMO.exe software tool is owned by sparkfun.

>> intro to our repository

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Directory structure:

fplib-GT521Fx2
______________
│
│   README.md
│   LICENSE    
│   fplibMicro.py
│   test.py
│ 
└───fplib
│   │
│   │   __init__.py 
│   │   fpmain.py
│  
└───documents
│   │
│   │   GT-521F52_Programming_guide_V10_20161001.pdf
│   │   GT-521FX2_datasheet_V1.1__003_.pdf
│   
└───junks
    │
    │   14518-04SerialPowerConnectorLabel.png
    │   MicroPython_logo_400x400.jpg
    │   ...
    │   python-logo-generic.svg

1. fplib folder

• This folder contains the python3 version of sensor library code.
• We have written the code in fpmain.py file.
• This code is developed by reffering programming guide for GT-521fxx fingerprint sensor, the pdf version of the guide is given in documents folder.

2. documents folder

• This folder contains 2 pdf files, a programming guide and a datasheet of the sensor we use.
• These 2 files are very important to get a better understanding about the working of the sensor and how to use them.

3. junks folder

• This folder contains many image files that we used in README.md file of this project/Repo.

4. fplibMicro.py file

• This is the implementation of sensor code specially written for MicroPyhton supported devices, such as raspberry pi pico , esp32 e.t.c.. . I have tested the code on both the board and it works fine.

5. test.py file

• In this file i have done testing of different functionalities that is supported by the sensor.
• You can look onto it, and get a better idea on how to use this library for your needs.

>> intro to the library code and its testing.

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1. initializing communication with the sensor.

• First of all connect the device to your computer and make a note of the communication port allocated to the device.

Fig.2 - Sensor connected to a raspberry pi pico microcontroller.

• now we are importing the library to our python code.

from fplib import fplib

• after calling the library we need to initialize communication with the device using the port id.

# fingerprint module variables
fp = fplib(port=0, baud=115200, timeout=3)

# module initializing
init = fp.init()
print("is initialized :", init) 

OUTPUT:

is initialized : True

• so if the output is True then the communication with the sensor is initialized successfully.

2. Turning sensor LED - ON and OFF.

• To turn on the LED:

led = fp.set_led(True)
print("LED status :", led) 

• To turn off the LED:

led = fp.set_led(False)
print("LED status :", led) 

• for both the cases, if the sensor executes the instruction successfully will return True as output.

Fig.3 - Sensor LED in ON state.

OUTPUT:

LED status : True

3. Checking if finger is pressed on the sensor or not.

• It is required to check if finger is pressed or not before enrolling or collecting templates, so to do this:

pressed = fp.is_finger_pressed()
print("is finger pressed :", pressed)

• if someone pressed on the surface of the sensor then the output will be True.

OUTPUT:

is finger pressed : True

4. Fetching fingerprint template from the sensor.

• We can collect fingerprint datas from different users using the following lines of code.

data, downloadstat =fp.MakeTemplate()
print(f"Is template fetched :", downloadstat)
img_arr = []
if downloadstat:
   data = bytearray(data)
   # converting bytes to integer
   for ch in data:
       img_arr.append(ch)
print("fetched template data: ", img_arr)

• if the fetching process succeed then we will get downloadstat as True .
• And we will get a template data of length 502 data points.
• We can use this data to upload it to the sensor memory.

OUTPUT:

Is template fetched : True

fetched template data: [1, 0, 4, 16, 100, 0, .... , 0, 0, 106, 68, 24, 70]

5. setting the fetched template to sensor memory.

• we can upload back the fetched template data to the device memory, so that the sensor can use this template to identify a user.

# the data should be of lenght 502 .
DATA = [1, 0, 4, 16, 100, 0, .... , 0, 0, 106, 68, 24, 70]
# idx -> is the id where we need to set the template.
fp.delete(idx=4)
status = fp.setTemplate(idx=4, data=DATA)
print("set template status :", status)

OUTPUT:

set template status : True

• if we get a status True then the template is set on specified index (here it is 4).
• So after setting the template we can identify the user .

6. identify a user.

• after collecting many templates using MakeTemplate() and setting those templates to sensor memory using setTemplate() method we can use the sensor for identifyong users using the below code.

id = fp.identify()
print("identified id:", id)

• This code will return the id if a match was found.

OUTPUT:

identified id: 4

Conclusion :

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• More functionalities are added to the library, you can find it in the code.

• some of the functionalities are:

  • • get fingerprint image
  • • enroll new users
  • • verifying users
  • • recognizing users
  • • e.t.c ..,

• Arduino code for this fingerprint sensor is available in official sparkfun repository : click here

License Information :

• MIT

THE END

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