I am working on a project when I have to enroll and Submit the attendance of the fingerprints.

What I have : I am able to enroll single fingerprint on a different unique ID. Using AdaFruit FingerPrint Sensor Library. I have :

R305 FingerPrint Sensor having 1000 fingerPrint storage and Arduino Uno

What I want : I want to enroll more than one finger Prints on same Unique Id. How to do it, Please anyone Help me with this. Help will be appreciated. Thanks

  • your project seems to have a lot of issues with privacy ... why are you capturing people's fingerprints? – jsotola Feb 20 '18 at 6:46
  • No, You are getting me wrong, it is just a college project but i want to enroll more than one finger on same unique id – Siddharth Sinha Feb 20 '18 at 6:49
  • i do not think that you can ... the reader outputs a unique ID for each fingerprint ... the controller has to keep track of all the ID numbers belonging to an individual – jsotola Feb 20 '18 at 7:22

Each fingerprint must have a unique ID that refers to that fingerprint.

What you need next is a table to associate multiple fingerprint IDs with "persons" so that you can find out which person belongs to a particular print scan.

You didn't say if you were holding fingerprint and person data within the Arduino or on some network-based storage system, but if we assume that this is entirely self-contained in the Arduino you would need to write the association table to some kind of storage that won't reset when the Arduino loses power, such as an EEPROM. The Uno has a "built in" EEPROM on the ATMega328p chip, but it only holds 1024 bytes. There are external EEPROMs that communicate via SPI or I2C that can hold more data.

As to the actual data structure -- it can be as simple as a 2-dimensional array, with one dimension holding the fingerprint ID, and the other holding a person ID. For multiple fingerprints of the same person, the table would have multiple rows with the same person ID, but different fingerprint IDs.

You could also make an array of struct datatypes, or create class, etc. But the point is that the "Unique ID" matching only ONE print from the fingerprint sensor is a limitation you have to work with.

Not the answer you're looking for? Browse other questions tagged or ask your own question.