We will start this chapter by learning to build our first electronic circuit around the Arduino Uno board. This will be our first hardware-software integrated prototype. Two examples have been chosen for this chapter. The first example is a series of three external red Light Emitting Diodes (LEDs). We will write an Arduino sketch that will blink the three LEDs, one at a time, in a cyclic fashion. The second example is using a Piezo Buzzer. We will learn to write a sketch to play a musical tune using the Buzzer.

The reason for starting off with these basic examples is to understand how to build a prototype using the Arduino platform. And what better way could there be than to show some light (using the LEDs) and make some sound (using the Buzzer)!

After reading through this chapter, the reader will understand the fundamentals of using basic electronic components such as resistors, transistors, and diodes.

Things you will learn in this chapter:

• Use of resistors to reduce current flow
• Ohm's Law based resistance calculation
• Introduction to the breadboard
• Blinking multiple external LEDs
• Concept of common grounding
• Making sound with Buzzers
• Using transistors for switching
• Using rectifier diodes for preventing flow of current