A Simple App Controlled Door Lock

[Adnan.R.Khan] had a sliding door latch plus an Arduino, and hacked together this cool but simple app controlled door lock.

Mechanically the lock consists of a Solarbotics GM3 motor, some Meccano, and a servo arm. A string is tied between two pulleys and looped around the slide of a barrel latch. When the motor moves back and forth it’s enough to slide the lock in and out. Electronically an Arduino and a Bluetooth module provide the electronics. The system runs from a 9V battery, and we’re interested to know whether there were any tricks pulled to make the battery last.

The system’s software is a simple program built in MIT App Inventor. Still, it’s pretty cool that you can get functionally close to a production product with parts that are very much lying around. It also makes us think of maybe keeping our childhood Meccano sets a little closer to the bench!

9 thoughts on “A Simple App Controlled Door Lock

  1. Correct me if I’m wrong, but anyone who connects to this device and then sends the text “L” through a bluetooth serial shell would be able to open this no? There doesn’t seem to be any security involved.

  2. Layout schematic doesnt match. Classic dual L293D motor shield is not Rotoshield. Clearly not a single 9V supply. Pulley system doesn’t seem to provide any mechanical advantage. It does appear to work so yay. Use of Meccano/Erector always stylish.

      1. No mechanical advantage. If placed a wrapped cylinder on motor could at least get a better torque and a longer linear capability. Otherwise a simple bar linkage more effective and less parts. Agreed not a front page but peer review has value.

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