Circuit Theory

As shown in Figure 8-1, the LED wiring is quite different from previous projects, because an electrical ground and a +5V battery are used to individually operate them. The idea behind this wiring technique is to allow one LED to be on at all times. The circuit schematic diagram in Figure 8-2 on the left shows LED1 on while LED2 is off.… Continue reading Circuit Theory

Parts List

Figure 8-1. The Up-Down Sensor block diagram TECH NOTE A tilt control switch is sometimes called a tilt sensor.

Introduction

Up-Down Sensor The FrankenBot toy illustrated the method of flashing two LEDs wired in parallel. The Arduino microcontroller made it easy to change the flash rate of two LEDs using a 10KΩ potentiometer. How cool would it be to control an LED’s flash rate by moving an electronic box in an up-down motion? This project is a… Continue reading Introduction

The Arduino OR Logic Gate

You can build a digital computer OR Logic Gate circuit using the Arduino microcontroller and a few electronic components. The green LED turns on when either the pushbutton switch OR the photocell is TRUE. You can easily build the logic circuit using the Fritzing wiring diagram shown in Figure 7-6. You can build this basic digital computer circuit on… Continue reading The Arduino OR Logic Gate

Circuit Theory

The OR Logic Gate is another computer circuit providing a TRUE output based on at least one input data value having a closed state. A basic OR Logic Gate electric circuit schematic diagram is shown in Figure 7-2. The circuit schematic diagram on the left shows one pushbutton switch closed and the other one open. The output for this… Continue reading Circuit Theory

Parts List

Figure 7-1. The assembled Arduino OR Logic Gate TECH NOTE When two or more electrical/electronic components are connected across one voltage source via separate paths, this is called a parallel circuit. In a parallel circuit, there are different ways that electricity can flow.

Introduction

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… Continue reading Introduction

Something to Think About

How can the photocell be wired to analog A0 and be used as a digital input pin? Figure 6-10. The Arduino AND Logic Gate circuit schematic.