College students have returned in droves to dorms and apartments at campuses everywhere. So this is the time of year we usually start seeing some coded entry hacks. [Charmonkey] recently took on the ...

[Jeremy Blum] wrote in to share his LibeTech QR Code Door Lock project. He developed it during his Senior year at Cornell University along with three of his classmates. It seeks to move away from ...

You don’t need to continue using keys and key cards. When you want effective first-line security for private doors in public spaces, you no longer need cumbersome kit. To keep opportunist hands off ...

To open a door fitted with the latest U.S. government-certified lock from high-end Swiss lock manufacturer Kaba, an employee must both enter a code up to eight digits long, then swipe a unique ...

We independently review everything we recommend. When you buy through our links, we may earn a commission. Learn more› By Doug Mahoney Doug Mahoney is a writer covering home-improvement topics, ...

The main principle of this circuit is that the door lock opens only when the buttons in series are pressed at a time. We can use it to lock the doors and for other security purposes. This article ...