Let There Be Light

This project uses a Raspberry Pi, Google Home, and IFTTT, as well as handmade hardware, to automate the opening and closing of curtains/blinds as a smart home application.

Table of Contents

• Cloning the repository and running the software
• IFTTT Integration
• Hardware Dependencies
• Online Resources
• Hardware Build

Cloning the repository and running the software

1. Ensure you have installed node.js on your device. It is available from https://nodejs.org/en/download/
2. Fork or clone this repository onto your device.
3. In the console, run npm install to install the required components.
4. In app.js, change PASS = to your chosen password
5. Run npm start or node app.js to launch the server

When you make a GET or POST request to the server, use the structure: http://ipaddress/api/<command>?password=<yourpassword>

where <command> = open or close

IFTTT Integration

This project can be operated by making GET requests in a web browser to the server, for example if a Google Home device is not available. However, the project works much better as a smart home application using a Google Home device and IFTTT.

To set up IFTTT triggers:

1. Go to IFTTT.com and create an account if you don't have one
2. Go to IFTTT.com/create
3. Click the +This in If +This Then That
4. Search for and select Google Assistant. You will be required to connect your Google account if you haven't before
5. Select Say a simple phrase
6. Fill in the fields as follows, adjusting as you see desire:
   • What do you want to say = Open the curtains
   • What do you want the Assistant to say in response? = Okay. Opening the curtains
7. Click Create Trigger, then click the +That in If This Then +That
8. Search for and select Webhooks, and then Make a web request
9. Fill in the fields as follows, adjusting as you see desire:
   • URL = http://ipaddress/api/open?password=<yourpassword>
   • Method = GET or POST
   • Content Type = text/plain
10. Click Create Action, then Finish
11. Repeat the same process from step 2 with the following adjustments:
    • In step 6 change open to close and opening to closing
    • In step 9, set the URL = http://ipaddress/api/close?password=<yourpassword>

You should now be able to issue voice commands to a Google Home/Google Assistant device and web requests will be made automatically to your server.

Hardware Dependencies

This project uses:

• A Google Home
• A Raspberry Pi (I used a Pi Zero W running Raspbian, any RPi with WiFi capability should work)
• Prototyping Breadboard
• 6V DC Motor
• L293D H-Bridge Motor Driver
• Jumper wires
• 4xAA battery pack
• Handmade motor wheel
• Curtains/blinds with bobbly pull cord

Online Resources

• This project is inspired by and based on krpeacock's google_home_starter project
  • The instructable for his project can be found at https://www.instructables.com/id/Google-Home-Raspberry-Pi-Power-Strip/
  • The GitHub page for his project can be found at https://github.com/krpeacock/google_home_starter
  • Credit to Kyle Peacock for the IFTTT integration and original Software design
• Circuit design for RPi motor control based on tutorial at https://business.tutsplus.com/tutorials/controlling-dc-motors-using-python-with-a-raspberry-pi--cms-20051
• Datasheet I used for the L293D Motor Driver can be found at https://static.rapidonline.com/pdf/82-0192.pdf
• Node.js can be downloaded from nodejs.org/en/download and documentation can be found at nodejs.org/en/docs
• IFTTT website at IFTTT.com
• Raspberry Pi Zero GPIO Diagram:

Hardware Build

This project depends on handmade hardware to perform the physical action of opening curtains/blinds.

The hardware is shown below, with jumper wires from the Raspberry Pi's GPIO pins to the L293D on the prototyping breadboard, and wires from the L293D to the motor.

Circuit Overview

RPi GPIO Connections

Breadboard Circuit

Motor Connections

Handmade Motor Wheel

Circuit Connections:

• Pi 3.3V to L293D pin 16 (Vss)

• Pi Ground to Breaboard - power rail (Ground)

• PI GPIO to L293D pin 2 (Input 1)

• PI GPIO to L293D pin 7 (Input 2)

• PI GPIO to L293D pin 1 (Enable 1)

• Battery pack + wire to breadboard + power rail (Power)

• Battery pack - wire to breadboard - power rail (Ground)

• Breadboard + power rail (Power) to L293D pin 8 (Vs)

• Breadboard - power rail (Ground) to L293D pins 4, 5, 12, 13 (GND)

• L293D pin 3 (Output 1) to motor

• L293D pin 6 (Output 2) to motor