Building iPhone and iPad Electronic Projects

Chapter 12. WiFi Servos

About This Chapter

Prerequisites

Read Chapter 11 first to get a grounding in WiFi connections and an introduction to the WiFly board.

Equipment

You will need an iPhone, iPod, or iPad running iOS 5 or later. You will also need a WiFly device, a Polulo Serial Servo Controller, a micro servo, and various common electronics parts, like a small regulated power supply, jumper wires, and a breadboard. See Table 12-1 for a complete parts list.

Software

You will need a copy of techBASIC or techBASIC Sampler and a copy of the Arduino software for programming the Arduino microcontroller. The Arduino software is a free download.

What You Will Learn

This project shows how to use a WiFi to serial bridge to set up communication with a servo controller. After a fun introductory project that essentially just turns the servo, we’ll hack a candy dispenser to give candy on demand.

Servos: They’re Where the Action Is

One of the most versatile mechanical devices available for robotics, or pretty much any kind of physical control work, is the servo (shown in Figure 12-1). A servo is a package containing a motor and electronics that responds to a signal by rotating to a specified location. Give it one value, and it will spin to the left; another spins to the right. Simple mechanical linkages (aka horns) can turn this motion into a push-pull motion, which is how servos control radio-controlled model airplanes. Servos are generally limited to about 180 degrees of motion, but they can easily ...