This chapter introduced the first sensor system for the BOE Shield-Bot, and allowed the robot to roam around on its own and navigate by touch.  The project built on skills acquired in the last chapter, and employed a variety of new ones:

Electronics

• Building normally open, momentary, single-pole, single-throw, tactile switch circuits

Programming 

• Using the Arduino language’s pinMode and digitalRead functions to set a digital I/O pin to input and then monitor the pin’s input state
• Declaring and initializing global variables
• Nesting function calls
• Using if…else statements to direct program flow based on sensor input states
• Using three levels of nested if statements

Robotics Skills

• Autonomous robot navigation based on sensor inputs
• Using a simple example of artificial intelligence so the autonomously roaming BOE Shield-Bot can tell if it’s stuck in a corner, and exit

Engineering Skills

• Subsystem testing again—build that good habit!
• Using an indicator LED to visibly display the state of a system input
• Using an indicator LED to visibly display program flow