Let’s say that you don’t have your smartphone around and someone mentions you on twitter. Wouldn’t it be nice to have a display that automatically reads your twitter mentions and show it on a scrolling display? So let’s build a internet controlled (IoT) dot-matrix display that does this for us using an ESP8266.
The plan to accomplish this is as follows:
- Someone mentions us on twitter (in my case @debsahu)
- IF This Then That (IFTTT) tracks these mentions and posts this data on Adafruit.io (MQTT Broker)
- An ESP8266 connects to Adafruit.io and shows this data on a Dot-Matrix display
We can’t control who mentions us on twitter, so we move to the second step in our plan to configure IFTTT and Adafruit.io.
To setup a data feed (MQTT topic) on Adafruit.io,
- Goto “feed” and “Create New Feed”
- Provide a unique name for the feed like “twitter-calls”, this means the MQTT topic that we need to subscribe to is “feed/twitter-calls”
To setup IFTTT to connect to twitter and Adafruit.io,
- Connect your twitter and Adafruit.io account to IFTTT by logging in and giving proper permissions
- Create a new applet
- For “this“: Select “twitter” and “New mention of you”
- For “that“: Select “Adafruit” and “Send data to Adafruit.io”. Remember to select the correct topic created above and a message template using ingredients that suits your need.
As a part of the third step in our plan, we need to subscribe to our MQTT topic and display this data on a Dot-Matrix display.
- Setup Arduino IDE to be able to program an ESP8266 (Instructions on how to do this is here as well as in the video below).
- Install Adafruit_MQTT and MAX7219 Dot-Matrix display libraries
- Upload the code found here on your ESP8266
Make these following connections between Max 7219 display and Wemos D1:
- VCC -> 5V
- GND -> GND
- DIN -> D7
- CS -> D8
- CLK -> D5
That’s it, now you should be able to see your latest twitter mentions on your Dot-Matrix displays.