A cheap solution to keep them away from your secret room.
Have a secret room to keep safe? This project shows you how to use a general Wiegand keypad to control an electronic door lock with the help of Iono, an I/O module based on Arduino.
Wiegand keypad. I’m using an HID keypad with a beeper and a LED light integrated; I use them to signal an access being granted or denied. You may use any Wiegand keypad and external light and buzzer or just skip them.
Iono board (both UNO and Ethernet versions are OK).
Electronic door lock.
Wire up your components as shown here:
On the Iono board, make sure to move the two DI5 and DI6 jumpers in the bypass position:
After uploading the provided sketch on the Iono board, you are ready to use your access control system.
First, set your pin code: when you set DI1 high (i.e. connect it to C+) the controller goes to programming mode. Enter your secret PIN code on the keyboard followed by ‘#’, the beeper will be activated for 2 seconds. Now your code is stored on Arduino’s EEPROM, therefore it will be kept memorized even if you power off the board.
Disconnect DI1 from C+ and you are ready to unlock your door entering your secret PIN (followed by ‘#’).
The provided sketch will alert with 3 short beeps in the case a wrong code in entered or, in case of correct PIN, will activate the door relay (unlock the door) and the LED relay for 4 seconds and play a 1-second beep.
You can easily modify those behaviours editing the provided sketch to make it fit your needs.
For the sketch code details check out this project on Hackster: