Fingerprint unlocking electronic lock based on ESP32

[Justinli]

I recently saw an article about a simple fingerprint unlocking electronic lock project article, and I really want to make a change according to this article. The article is using a fingerprint sensor module, and I would like to change it slightly here. A fingerprint sensor module is not very cheap, and I wanted to make the most of the resources at hand to complete the project. So I came up with the idea of using a touchscreen display to simulate fingerprint unlocking. Although the actual touch screen doesn't do fingerprint recognition, I wanted to find a way to replace this recognition and make it "fingerprint recognition" with something else.
I wonder if anyone can understand what I'm trying to say?

 

[KlausST]

Hi,

you want the fingers to do something "unique", like some movements, press and lift finger on specific positions, and the touch can detect this as "your unique movement pattern" and unlock the electronic.

Cellular phones do this with the unlock pattern. To ease positioning they often show a 3 x 3 dots matrix on the screen.

Or they show a numeric or alpahnumeric keyboard on the screen and you may input your pin or password.

You are free to show a blank screen (which makes it more difficult for you to find the correct positions) or you may show any picture.

Klaus

 

[Justinli]

Hi,

you want the fingers to do something "unique", like some movements, press and lift finger on specific positions, and the touch can detect this as "your unique movement pattern" and unlock the electronic.

Cellular phones do this with the unlock pattern. To ease positioning they often show a 3 x 3 dots matrix on the screen.

Or they show a numeric or alpahnumeric keyboard on the screen and you may input your pin or password.

You are free to show a blank screen (which makes it more difficult for you to find the correct positions) or you may show any picture.

Klaus

It's true that it's easier to enter a password, but it would be cooler if you could pretend to "unlock with your fingerprint" I think. I'm trying to figure out how I can pretend to do that.

 

[KlausST]

Hi,

Although the actual touch screen doesn't do fingerprint recognition,

Here is the key point.
They don´t do because they are not able to.
Fingerprint sensor are more "image sensors" than "position sensors".

I´m sure in future there will be touch sensors able to recognize finger prints.
But with nowadays cheap DIY touch sensors I´d say this is impossible.

Klaus

 

[Justinli]

Hi,


Here is the key point.
They don´t do because they are not able to.
Fingerprint sensor are more "image sensors" than "position sensors".

I´m sure in future there will be touch sensors able to recognize finger prints.
But with nowadays cheap DIY touch sensors I´d say this is impossible.

Klaus

Maybe you are right, if I really can not find a replacement method then I have to give up the fingerprint recognition method to use the password method.

 

[BradtheRad]

The fingerprint scanner must be like a camera taking a picture.
To homebrew your own stand-in...
Suppose you mount several photosensors, wired so that they send an OK when you place your finger over certain sensors?
Thus some must be dark while the rest are illuminated.
You can put some kind of screen on top of the sensors to hide their positions, while only you know where they are. Or as an alternative, use momentary pushbuttons.

 

[Justinli]

I have a new idea, maybe I can set up a dynamic scanning gif at a specified location on the screen, place an invisible button on the gif when I press it actually press the button, then the screen sends a message to the microcontroller to make it control the electronic lock to unlock.
The feasibility of this method may be higher.

--- Updated Jul 8, 2021 ---

The fingerprint scanner must be like a camera taking a picture.
To homebrew your own stand-in...
Suppose you mount several photosensors, wired so that they send an OK when you place your finger over certain sensors?
Thus some must be dark while the rest are illuminated.
You can put some kind of screen on top of the sensors to hide their positions, while only you know where they are. Or as an alternative, use momentary pushbuttons.

Thank you for your reply, the sensor may also be a solution.

 

[KlausST]

Hi,

The touch works with or without a picture. It's an independent device.
You may print out any photo on paper and put it behind the touch instead of a TFT if you like.

On finger_press it just sends out the X- and Y- coordinates of the finger position. (On simplest case)

Klaus

 

[Justinli]

Hi,

The touch works with or without a picture. It's an independent device.
You may print out any photo on paper and put it behind the touch instead of a TFT if you like.

On finger_press it just sends out the X- and Y- coordinates of the finger position. (On simplest case)

Klaus

Hi Klaus, I can't put the printed paper behind the screen, it's not a mere display screen, it's a module which has the backside as shown in the picture.

It has its own GUI design, and I think I can make good use of that.
I'll be thinking about the method, and I'll update here as soon as I have progress.
I hope you can give me more ideas!

 

[Aussie Susan]

A Google search shows there are a number of finger print detectors out there, some as USB dongles etc., for a few 10's of dollars.
You can probably build something into the side of the screen or box to do what you want.
Susan

 

[Justinli]

A Google search shows there are a number of finger print detectors out there, some as USB dongles etc., for a few 10's of dollars.
You can probably build something into the side of the screen or box to do what you want.
Susan

Yeah, maybe I'll just have to buy an extra fingerprint sensor, I guess in that case I'll just use a regular LCD.