The touch sensitive lock uses the CapSense Arduino library. By turning the door handle into a touch sensor, [Rob] allowed a secret code to be saved in the EEPROM.

The touch sensitive lock uses the CapSense Arduino library. By turning the door handle into a touch sensor, [Rob] allowed a secret code to be saved in the EEPROM.

If that sounds like a dream come true, then you might need one of these Secret Knock Detecting Door Locks. This innovative device was made using an Arduino, a motor, and a piezo sensor.

Thank you for having a gander at my 19th Kickstarter Campaign! Let me introduce you to the “Tommy-Knocker”! This neat little project board is Arduino compatible, can program a secret knock ...

Steve Hoefer’s secret knock detector is little more than a piezo speaker, a tiny gear reduction motor, an Arduino and some PVC pipe—basically a bunch of stuff he had lying around the lab. It ...