Did You Lock the Door?! There's an Answer to That!

Trevor English

It has happened to many of us. We've left home or office and shortly after leaving, we started wondering whether or not we locked the door properly. If that question has ever occurred to you, you might be happy to know that finally some designers have come up with a solution for that. This small little device called the KPHOB tells you whether you locked your door or not by displaying the time and date the door was last locked up!


KPHOB is a key fob that registers the time and the date of each time you lock or unlock a door, so in case you have any doubts, you could check the records and make sure you did lock the door last time you left the house.

key fob lock device sixe[Image Source: KPHOB]

They are now on Kickstarter where you can pre-order your key fob with early bird discounts. If you don't know about Kickstarter, It is a platform to help bring creative projects to life. It helps developers by gathering money from the public, which circumvents traditional avenues of investment.

parts to the lock[Image Source: KPHOB]

KPHOB is a stand-alone product which combines two sensing methods to detect key usage and key rotations.

You would be required to place a tiny permanent magnet on the doors that you want to track. This magnet serves to activate the proximity sensor that is deployed in the key fob. As a result, every time your key fob is in a certain proximity to the door (5 cm or less), it would wake up the device from standby mode, register the time and start monitoring further motions of the key. In the next step KPHOB uses a magnetometer so it can measure the relative orientation of the key fob and consequently the key itself towards the magnet.