Introduction: Fingerprint Scanning Doorlock With Access History Printer

Hi everyone. Welcome to my second instructable. Today I am gonna show ya how to make a Fingerprint Scanning doorlock that can also print out who came in and if any stranger tried this too. To do this we'll be using the Adafruit thermal receipt printer, a very cute little printer and a GT-511C1 fingerprint scanner. So if you're ready let's go to step 2: Parts and Tools.

UPDATE: I had made a few mistakes in the materials and the code but I corrected them. ;)

Step 1: Parts and Tools

For this instructable you will need the following. The things are clickable.

x1 Arduino UNO (Or any other arduino except mini and micro)

x1: Adafruit thermal printer.*

x1 GT-511C1 fingerprint scanner (GT-511C3 will work too)

x1 JST SH Jumper 4 Wire Assembly - 8"

x2 Infrared Sensor Jumper Wire - 3-Pin JST *

x2 Jumper Wires Premium 6" M/F Pack of 100 (Or any cheaper you find)

x1 Solid State Relay - 40A (3-32V DC Input)

x1 12v door electric strike of your choice.

x1 Female DC Power adapter - 2.1mm jack to screw terminal block *

x1 5V 2A (2000mA) switching power supply - UL Listed *(Or any similar of your country)

x1 12V power supply of your choice

and WIRE Solid core


Soldering iron


Soldering grea

* These are sold in a set too which you can find here

Well I think that's about it. So let's head to part 3: Wiring.

Step 2: Wiring

Here come the schematics.

Step 3: Programming.

That's the program. Feel free to hack it away but copy the first lines.

Step 4: Preparing the Strike

To prepare the strike you need to solder it to the relay and embed the 12 v power supply.

Something like this

Step 5: Dress It Up.

Now you will need something to put the whole thing in.

For the inside module you can use a nice carton box or wooden box if you want to be fancy.

As for the outside module you can use the case from Nodah's fingerprint Scanning garage door opener.

Step 6: Troubleshooting

If the fingerprint scanner does not turn on check if you wired it correctly.

If the printer does not print the 'Finger not found' and 'Verified ID' things try connecting the RX and TX wires (yellow and green) the other way around.

If the printer didn't print some diagnostics and the fonts, when you plugged it in, this means you might have connected the power supply the wrong way (Connect it the other way around) or it's busted (Contact adafruit).

That will be all !

If you have any other problem leave me a comment and I will do my best to answer it.


Epilog Challenge VI

Participated in the
Epilog Challenge VI