TUTORIAL 3 :: ETHERNET SHIELD AND TWITTER.COM

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1 TUTORIAL 3 :: ETHERNET SHIELD AND TWITTER.COM Pachube.com orchestrates a global, open-source network of Inputs and Outputs. However, as an infrastructure it is limited in two major ways: 1) you can t carry it with you. 2) it is not culturally imbedded. We will overcome these limitations through the use of cellphones and Twitter.com. We ll also remove our dependence on the computer s internet connection by integrating the Ethernet Shield with Arduino. Among other things, Twitter.com allows users to send SMS commands from their cellphone to a Pachube.com feed. Practically everyone has a cellphone; cellphones are practically everywhere. Although our Arduino projects are not everywhere, we can harness the cellphone so that we might reach beyond the local toward the global remote, thereby broadening the potential of Inputs and Outputs to bring Architecture to life. PART 1 :: TWITTER.COM QUICKSTART 1. Create a new Manual Feed in your Pachube.com account. Take note of the feed ID - we will use it later. 2. Create a new account on Twitter.com. 3. From your Twitter.com account, tweet the message follow pachtweet using the text entry box. This is called a public tweet. You can also send Direct Messages (DM), which are private. The user pachtweet acts as a courier, delivering your commands from Twitter.com to Pachube.com. 4. Tweet the connect into the text entry designates the recipient, connect is the message. Wait for the user pachtweet to send you a DM. Direct Messages can be found under the menu list on the right.

2 5. Reply to pachtweet s DM with the message key YOUR_PACHUBE_KEY This is a one-time authentication process, allowing only your Twitter.com account to access your Pachube.com feeds. YOUR_PACHUBE_KEY is also called your API Key, and you can find it under Settings inside your Pachube.com account. You are now ready to send commands to your Pachube feed by using Direct Messages in Twitter.com. 6. To begin controlling your Arduino project, send a DM to pachtweet that follows this format: set FEED_ID STREAM0,STREAM1,STREAM2,... set is a prefix that tells pachtweet you want to enter new data into a feed. FEED_ID designates the feed ID where you want to send the data. STREAM designates the data to be sent. Streams are ordered sequentially by commas with no spaces. You may have multiple Streams in a single Pachube.com feed. Streams will be listed on your feed in the same order you enter them here. 7. Add the option to send DMs using your cellphone. From your Twitter.com account, click Settings in the upper right. Click Devices, and follow the on screen instructions to set up your cellphone. Note that updates should be sent to while in the United States. See the Twitter Phone FAQ for dialing Twitter from other countries: Cellphone DMs follow a similar format when updating a Pachube.com feed: d pachtweet set FEED_ID STREAM0,STREAM1,STREAM2,... d is a prefix that tells Twitter.com that you want this to be a Direct Message. pachtweet designates the user to send the DM to. The rest is the same as Step DMs from Twitter.com or your cellphone will update your Pachube.com feed. We still need to set up the Arduino in order for those DMs to be read as commands. 9. Part 1 is now complete.

3 PART 2 :: ETHERNET SHIELD QUICKSTART 1. Purchase an original Arduino Ethernet Shield if you have not already done so: Ethernet Shield (top) info.php?products_id= Attach the Ethernet Shield on top of the Arduino. You will probably need to detach your Breadboard/LEDs. The Shield replicates all pins on the Arduino, however it uses pins 10, 11, 12, and 13, for it s own purposes. Relocate your Breadboard/LEDs so they do not use pins 10, 11, 12, and 13. Remember to update your sketch accordingly. Arduino USB Board (bottom) 3. Identify the IP address of a GSAPP computer. Use the following web address to find your IP address. Take note - we will use it later: 4. Carefully detach your GSAPP computer s ethernet cable and attach it to your Arduino Ethernet Shield. unplug from computer plug into Ethernet Shield 5. Open the WebClient sketch in the Arduino 12 environment: Open > Examples > Library-Ethernet > WebClient

4 6. Look to the sketch and update it with your IP address. Add a Gateway and Subnet array immediately following the IP array. You do not need to change your MAC address. IP addresses should be formatted with a comma followed by a space, like this: 100, 20, 300, 40 byte ip[ ] = { YOUR_IP_ADDRESS_HERE }; byte gateway[ ] = { 128, 59, 128, 1 }; byte subnet[ ] = { 255, 255, 252, 0 }; Your IP address is a set of four unique numbers just for you. If you have problems, try changing the last number to something higher, but leave the other numbers alone. Gateway and Subnet are specific addresses associated with Columbia University. They allow you to use Columbia s network. 7. Update Ethernet.begin() so it reads as follows: Ethernet.begin(mac, ip, gateway, subnet); 8. Upload the sketch to your Arduino. When the upload is complete, press the Serial Monitor button next to Upload to I/O Board. You should see a large stream of HTML from Google.com. Your Arduino and Arduino Ethernet Shield are now capable of accessing the internet. 9. Part 2 is now complete.

5 PART 3 :: ETHERNET SHIELD, PACHUBE, and TWITTER 1. In the Arduino 12 environment, open the Tutorial3_twitter file ed to you. Take a minute to review the sketch. You ll notice many familiar pieces of code, some of it slightly altered, some of it entirely new. It s been adopted from the Arduino Ethernet Pachube Input Output sketch, found here: ethernet_pachube_input_output.zip Note the three tabs. Tabs are essentially one very long sketch split into three pages for ease of viewing. 2. Create a new Manual Feed in Pachube.com. Take note of the feed ID. 3. Look to the sketch, and set SHARE_FEED_ID to the new feed ID you just created. 4. Set the REMOTE_FEED_ID to the feed ID that you want to access. Any Pachube.com feed ID is possible, but for this example we will access the feed ID you created for Twitter. com in Part Set the REMOTE_FEED_DATASTREAMS to the total number of streams you want to connect to. For example, if you want to connect to STREAM0, STREAM1, and STREAM2, set this value to Set the PACHUBE_API_KEY to your Pachube Key. 7. Enter your Mac, IP, Gateway, and Subnet addresses from Part 2. Upload the sketch to Arduino. 8. Part 3 is now complete. HOW IT WORKS: Using your cellphone, send an SMS to 40404: d pachtweet set FEED_ID A,B,C FEED_ID is the REMOTE_FEED_ID from Part 3 A is how long the LED will flash (try 55, then try 200 to compare) B turns the inside red LED on or off (try 1 for on, and 2 for off) C sets the brightness for the inside red LED (1 thru 255) Prepared by KEVIN WEI Living Architecture I: Responsive Kinetic Systems Lab, Spring 2009