Arduino password protected door access

Hello world! Today i made a simple code to control a electric strike lock with a Password / Access Code using a 1 channel relay to build a Arduino password protected door access control. I don’t have such a lock but i demonstrated it with a lamp attached to the relay.
(I know! I wrote access wrong in the video..don’t mind the

Arduino password protected door access

You need these following libraries

Wire it up like the schematic and it should work after uploading,
if you are not seeing anything, try change your I2C Address i will include a Code to scan your address.
You can change this at the line shown below which you can find on line 14 of the code of the Arduino password protected door access.

#define I2C_ADDR 0x27
Most common I2C addresses.

PCF8574 = 0x20,
PCF8574A = 0x38,
PCF8574AT = 0x3F
PCF8574T = 0x27

Parts list:
Arduino uno, I used the RobotDyn Uno.
1 Channel Relay KY-019
Keypad 4×4
LCD 1602 with I2C
Electrical Strike Lock (Not needed to test the code, you will see if relay go’s on or off.)


Danny van den Brande

Programmer, Game Designer, 3D Designer, Web Designer, Graphic Designer. Jup this website looks crappy.. :) But enjoy the projects! Everything you need is here.

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