This is a DIY smart display that you can embed in to your wall. You can control your smart appliance, set timer to control it, get weather info, and act as a cool clock. Let’s get straight into how I made it.

For more details visit https://www.eionix.co.in/2019/06/29/smart-home-display-iot-diy-google-home-hub.html

Architecture

Hardware

It consists of

• Frame
  • Front panel
  • Back panel
  • Processing Unit Cover
  • Relay Cover
• Display (7 inch 800x480 resolution)
• Processing Unit - Raspberry Pi
• Relay circuit (4 channel)

Panel and display are snapped together. Processing Unit and display are secured using screws. Processing unit and relay cover are attached using 3 mm screws.

Software

Chromium-browser is used in a kiosk mode where it render the UI from a backend server. Python with the help of Flask to serve both static pages and a REST API service. JS will invoke REST APIs to control and view stats of appliances.

REST API Service

1. List room names

   GET /api/

        {     "rooms":["room1","room2"]     }
   

2. List all appliances in a given room

   GET /api/{room_name}

        {       "Fan 1": {         "power-control": {           "enabled": true,            "level": 100         },          "status": true,          "timer": -1,          "type": "fan"       },        "Light 1": {         "power-control": {           "enabled": false,            "level": 100         },          "status": true,          "timer": -1,          "type": "light"       },        "Light 2": {         "power-control": {           "enabled": false,            "level": 100         },          "status": true,          "timer": -1,          "type": "light"       }     }
   

3. Change appliance properties

   POST /api/{room_name}/{appliance_name}

        {     "status":true,     "timer":10,     "power-control":{             "level":50             }     }
   

4. Scan wifi APs

   GET /api/wifi_scan

        {       "result":["WiFi-1","WiFi-2"]     }
   

5. Connect to an AP

   POST /wifi_connect

        {       "ssid":"WiFi-1",       "passkey":"password"     }
   

6. Disconnect already established connection

   POST /api/wifi_disconnect

        {     }
   

7. Get current ip

   GET /api/ip

        {       "ip": "192.168.1.5"     }
   

UI features

These shows the features that are supported.

CAD Design

I have used fusion 360 to model the parts.

3D printing

Thanks to Sumit Goyl for helping out with 3D printing and beautifully painting the parts.

  

Final preview