I have created a tutorial on how to use the Arduino+Ethernet Shield and ThingSpeak. You can use it to data log on the web, see charts, connect a device to the internet, or even send status updates to Twitter.http://community.thingspeak.com/tutorials/arduino/using-an-arduino-ethernet-shield-to-update-a-thingspeak-channel/
The sketch shows you how to send an HTTP POST to the ThingSpeak API. It's updated to use Arduino 22, the native String library, and includes a watchdog timer for the Ethernet Shield. When 5 failed transactions are detected in a row, the Arduino re-initializes the Ethernet Shield (soft-reset). This will not solve every lockup, but it will make the setup more stable.
ThingSpeakClient Sketch http://community.thingspeak.com/arduino/ThingSpeakClient.pde
Here's how you get started with the ThingSpeakClient sketch...
- Sign Up for New User Account - https://www.thingspeak.com/users/new
- Create a New Channel by selecting Channels and then Create New Channel
- Enter the Write API Key in this sketch under "ThingSpeak Settings"
A ThingSpeak Channel can hold any type of data - sensor data (decimal and comma), binary data, serial strings... You can also send geo location information in dedicated location for mobile things. We just released an app you can install that allows you to send Twitter updates without doing OAuth on the Arduino side. The other part of ThingSpeak is that you can get data from a channel and start connecting things together.
We welcome anyone to try it out and looking for feedback as the service is new. The source code for the API will go up on GitHub and be open source once the kinks are worked out. The app is localized with language YML files, so you can even translate into pirate if you want. We hope this makes it easier to connect things to the web.