Basic Arduino Projects

Chapter 7. The OR Logic Gate

Two Pushbutton Switches in Parallel

The OR Logic Gate is the final basic computer circuit used to make simple decisions with electrical input signals. The OR Logic Gate is different from the AND circuit because the two pushbutton switches are connected in parallel (instead of in series as with the AND circuit). The OR Logic Gate’s output decision is based on either one or the other input being TRUE. In this chapter, you will learn about the OR Logic Gate by building an Arduino OR Logic Gate using one pushbutton switch and a photocell. Figure 7-1 shows the assembled Arduino OR Logic Gate.

Parts List

• Arduino microcontroller
• MakerShield kit
• S1: pushbutton switch
• S2: pushbutton switch
• R1: 1KΩ resistor (brown, black, ...