Creating a WiFi-controlled Automatic Door Lock

Description

Tutorial Difficulty: Intermediate

Time Required: 15-20 minutes

Required Materials:
• The Omega
• The Expansion Dock
• The Servo Expansion
• A Servo Motor
• A Casing to attach the motor to the deadbolt
• A MicroUSB Power supply

Useful Experience:
• Using the Servo Expansion
• Using Shell Scripts
• Using JavaScript

Components

1 × The Onion Omega

1 × The Expansion Dock

1 × A Servo Motor

1 × A Casing to attach the motor to the deadbolt

1 × A MicroUSB Power Supply

Build Instructions

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1

Step 1

The Servo Motor
These motors turn using PWM signals. Our servo expansion has a pwm-exp function that can be used to generate these pulses. Most deadbolts lock and unlock at 90 degrees so modifications are not usually necessary. If your lock has to turn more than 180 degrees, you may want to modify your motor for continuous rotation.
2

Step 2

The Motor Casing
You will need a way to attach your motor to your door and `turn the lock. You can make a casing for the motor that can attach to your door and hold the motor in place. A small piece of plastic in the shape of the lock's bar should be attached to the motor.
An easy way to obtain these is to 3D print them. These are the models we are using .
3

Step 3

Storing lock state using UCI
OpenWRT is installed on the omega so you are able to use UCI to store configurations on the omega. So, we will use this to store the status of the lock. If your lock needs to turn more than 180 degrees, this would prevent the motor from applying a force on already locked/unlocked doors.