Update Twitter with ThingTweet and Arduino + Ethernet Shield

This tutorial explains how your Arduino via an Ethernet Shield can update a Twitter status using the ThingTweet App from ThingSpeak.

Setup ThingTweet

Sign in to https://thingspeak.com/login, select Apps from the menu, and then click on ThingTweet.
Under the ThingTweet App, select “Link new Twitter account”. This will redirect you to Twitter to see if you want the app to have the ability to access your account. You can Allow or Deny the process. Once you have confirmed the right Twitter account, Twitter will send you back to ThingSpeak.
The app generates a ThingTweet API Key for you to use. If you send an HTTP POST with your ThingTweet API Key, then the message will be relayed to Twitter. All of the parameters from the Twitter API (statuses/update) are possible including geolocation.

HTTP POST to ThingTweet

Here is an example HTTP POST to update a Twitter Status via ThingTweet:

POST /apps/thingtweet/1/statuses/update HTTP/1.1
Host: api.thingspeak.com
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: (number of characters in message)
api_key=(thingtweet_api_key)&status=My thing is social!

ThingTweet Arduino Sketch [Arduino 1.0+]

This Arduino sketch uses ThingTweet to update a Twitter status via an Arduino and Ethernet Shield.
Arduino_to_ThingTweet.ino

ThingTweet Arduino Sketch [Arduino 0023 or less]

This Arduino sketch uses ThingTweet to update a Twitter status via an Arduino and Ethernet Shield.
ThingTweet.pde