CHAPTER 12 ■ IOT PLATFORMS
271
Figure 12-28. Test trigger
Code (Arduino)
Next you are going to write the code for connecting Arduino to the Internet using WiFi,
reading soil moisture sensor data, and publishing it to a Xively channel.
Start your Arduino IDE and type the code provided here or download it from the site
and open it. All the code goes into a single source file ( *.ino ), but in order to make it easy
to understand and reuse, it has been divided into five sections.
•
External libraries
•
Internet connectivity (WiFi)
•
Read sensor data
•
Xively (publish)
•
Standard functions
External Libraries
The first section of code, as provided in Listing 12-1 , includes all the external libraries
required to run the code. This sketch has multiple dependencies—for Internet
connectivity you need to include the (assuming you are using a WiFi shield)
and for Xively connectivity, you need to include and . You
can download from https://github.com/xively/xively_arduino .