Arduino Twitter Library with OAuth Support

Arduino Twitter Library allows you to tweet directly from your Arduino board (equipped with an Arduino Ethernet Shield) without any intermediate servers or proxies. The library requires about 1400 bytes of SRAM and about 22kB of Flash memory so its runs quite nicely on Arduino Duemilanove and newer boards.

You can download the Arduino Twitter Library with all supporting libraries from GitHub.

The git repository includes a fully-functional Arduino Sketch for tweeting 1-Wire temperature sensor values to a configured Twitter account. Please, see the Twitter/Twitter.pde for the details.

Recent Changes

2012-02-27: Updated the project to compile with the Arduino IDE 1.0.

Getting Started

The following sections describe the basic library configuration and usage in more details.

Basic Twitter Library Configuration

Instantiate one Twitter instance and pass a working buffer for it. The twitter library needs around 400 bytes for its operation:
/* Work buffer for twitter client. This shold be fine for normal operations, the biggest items that are stored into the working buffer are URL encoded consumer and token secrets and HTTP response header lines. */ char buffer[512]; Twitter twitter(buffer, sizeof(buffer));
Configure Twitter endpoint names, Twitter (or HTTP proxy) server IP address and TCP port number, optional HTTP proxy usage, and Twitter client identifiers (i.e. application consumer key and secret) in your setup() function:

void setup() { ... twitter.set_twitter_endpoint(PSTR("api.twitter.com"), PSTR("/1/statuses/update.json"), server_ip, server_port, true); twitter.set_client_id(PSTR("*** consumer key here ***"), PSTR("*** consumer secret here ***")); ... }

Getting Twitter Account Access Tokens

The Arduino Twitter library implements the OAuth request signing but it does not implement the OAuth Access Token retrieval flow. This means that you need to authorize your Arduino Twitter application with your PC before you can start accessing the Twitter account from Arduino. Once you have retrieved the account access token and token secret, you can configure them for the Arduino Twitter library and you can start using the library.

I have used the following method for retrieving the account access tokens (but there might be easier ways too):

Download OAuthTwitterExample.zip from oauth-signpost wiki
Open src/Main.java and configure you twitter application's (the software running on the Arduino board) consumer key and consumer secret for the oauth-signpost's OAuthConsumer:

OAuthConsumer consumer = new DefaultOAuthConsumer("iIlNngv1KdV6XzNYkoLA", "exQ94pBpLXFcyttvLoxU2nrktThrlsj580zjYzmoM", SignatureMethod.HMAC_SHA1);
Compile src/Main.java
Run OAuthTwiterExample and follow the instructions:

java -cp commons-codec-1.3.jar:signpost-core-1.1-SNAPSHOT.jar:bin Main Fetching request token from Twitter... Request token: g1re4iYfknOYMB62JZkddjwhCfvfn4WPdZrzgscMOA Token secret: wKStK0dmhPcuFxBki3imJv7yVNXgRndmW4LSmuCg Now visit: http://twitter.com/oauth/authorize?oauth_token=g1re4iYfknOYMB62JZkddjwhCfvfn4WPdZrzgscMOA ... and grant this app authorization Enter the PIN code and hit ENTER when you're done: xxxxxxx Fetching access token from Twitter... Access token: 14418463-Xt70aZ8b2jz19MzY7JnQJ6HglPh0Hc5p939gLH5YI Token secret: TkG689FOx7amgdX2ta6epE5MYsmZxVuO9ith7FtJrs Sending request to Twitter... Response: 200 OK
Now you have an access token and secret for your Twitter account.

Configuring Twitter Account Access Tokens for Arduino

There are two ways how you can configure the account access tokens for the Twitter library:

Inline the credentials in your arduino sketch and pass them from the program memory to the Arduino Twitter instance:

/* Set OAuth account identification from program memory. */ twitter.set_account_id(PSTR("*** set account access token here ***"), PSTR("*** set account token secret here ***"));
Store the credentials in EEPROM and pass the EEPROM addresses to the Arduino Twitter instance:

/* Read OAuth account identification from EEPROM. */ twitter.set_account_id(256, 384);

And Finally, Start Tweeting!

After the library configuration has been done, it is very easy to send tweets with the library:

void loop() { ... if (twitter.is_ready()) { if (twitter.post_status("Hello, Arduino!")) Serial.println("Status updated"); else Serial.println("Update failed"); } ... }

Smallprint

Please, read and follow the Twitter Automation Rules and Best Practices guidelines.