Arduino: A Technical Reference

Chapter 10. Creating Custom Components

The more you work with Arduino devices in general, and the AVR microcontroller in particular, the more you may come to realize just how flexible and versatile they are. There seems to be a sensor or shield for almost any application you might imagine, and new shields appear on a regular basis. Even so, there are still a few applications for which there is no shield. There may be times when you spend hours online searching fruitlessly for a shield with specific capabilities, only to finally realize that it just doesn’t exist. In that situation you basically have three choices: first, you could just give up and try to find another way to solve the problem; second, you might find someone to build it for you (for a fee, usually); or third, you could design and build your own PCB. This chapter describes two projects that illustrate the steps involved in creating a custom shield and an Arduino software–compatible device.

The first project is a shield, shown in Figure 10-1, that is intended for a specific range of applications. The GreenShield, as I’m calling it, is based on a conventional shield form factor. It utilizes surface-mount components in a layout that includes potentiometers, relays, and LEDs.

When coupled with an Arduino the GreenShield will be able to function as a stand-alone monitor and controller for gardening or agricultural applications. This shield can also serve as the foundation for an automated weather station, a storm warning ...