Arduino – LCD 1602A I2C – PASSWORD PROTECTED DOOR ACCESS With Relay – KY-019

Hello world! Today i made a simple code to control a electric strike lock with a Password/ Access Code using a 1 channel relay. I don’t have such a lock but i demonstrated it with a lamp attached to the relay. Check the next step for the schematic code & Parts list.

(I know! I wrote access wrong in the video..don’t mind the typo..lol.)

Step 1: Schematic, Code & Parts List

You need these following librarys

  • password.h
  • LiquidCrystal_I2C.h
  • Keypad.h

Wire it up like the schematic and it should work after uploading,

if your 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.

  • #define I2C_ADDR 0x27

Most common I2C addresses.

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

Parts list:

  1. Arduino uno, I used the RobotDyn Uno.
  2. 1 Channel Relay KY-019
  3. Keypad 4×4
  4. LCD 1602 with I2C
  5. Electrical Strike Lock (Not needed to test the code, you will see if relay go’s on or off.)

Good luck!

Source: Arduino – LCD 1602A I2C – PASSWORD PROTECTED DOOR ACCESS With Relay – KY-019


About The Author

Muhammad Bilal

I am a highly skilled and motivated individual with a Master's degree in Computer Science. I have extensive experience in technical writing and a deep understanding of SEO practices.

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