This document describes an Arduino project that uses dip switches and LEDs. The objective is to have an array of 4 dip switches that can be configured by the user in different on/off combinations. The Arduino will continuously read the dip switch values and display the corresponding pattern on an array of 4 LEDs, so the LEDs always indicate the positions of the dip switches. The Arduino code defines the LED and dip switch pins and reads the dip switch input to control the LED output, illuminating the matching LED for each on dip switch. A schematic shows the wiring and a protoboard demonstrates the working circuit. Potential improvements discussed are using smaller dip switches and larger LEDs.

1. ET 320 – Microprocessors
Assignment #1 – LEDs with DIPs switches
By Bach Nguyen
Instructor: Dr. Cris Koutsougeras

2. Abstract
LEDs and DIPs switches are common electronic objects that are the foundation of
modern electronics. LED lighting products use light emitting diodes to produce light very
efficiently. An electrical current passes through semiconductor material, which illuminates the
tiny light sources we call LEDs. The heat produced is absorbed into a heat sink. Common LED
colors include amber, red, green, and blue. Colored LEDs are widely used as signal lights and
indicator lights, like the power button on a computer. LEDs are better than fluorescent and
incandescent light bulbs considering the less power and space consumption. A dip switch is a set
of small switches in a dual in-line package (DIP) that is used to change the operating mode of a
device. Dip switches are used to configure computer peripherals such as hard drives, modems,
sound cards, and motherboards.
Objective
A prototyping board will be equipped with dip switches and LEDs. An array of 4
switches which can be placed in random on-off combinations by a user. The Arduino must
continuously read the values of the 4 switches and display the array of values on a corresponding
output array of LEDs. So the LEDs must indicate the positions of the switches at all times.
Warning: there must be no direct signal path from the switches to the LEDs. The LEDs must be
under the control of the Arduino and its programming.
Methodology and Schematics
Arduino Codes:
int led1 = 2;
int led2 = 3;
int led3 = 4;
int led4 = 5;
int s1 = 6;
int s2 = 7;

3. int s3 = 8;
int s4 = 9;
// the setup routine runs once when you press reset:
void setup() {
// initialize the digital pin as an output.
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
pinMode(s1, INPUT);
pinMode(s2, INPUT);
pinMode(s3, INPUT);
pinMode(s4, INPUT);
}
// the loop routine runs over and over again forever:
void loop() {
if (digitalRead(s1) == HIGH){
digitalWrite(led1,HIGH);
}
else digitalWrite(led1,LOW);
if (digitalRead(s2) == HIGH){
digitalWrite(led2,HIGH);
}
else digitalWrite(led2,LOW);
if (digitalRead(s3) == HIGH){
digitalWrite(led3,HIGH);
}
else digitalWrite(led3,LOW);
if (digitalRead(s4) == HIGH){
digitalWrite(led4,HIGH);
}
else digitalWrite(led4,LOW);
delay(100);
}
Schematic:

5. The switches are wired to the Arduino as inputs and the outputs are perceiving as LEDs
according to the switches. When the switches are turn on the LEDs will be turn on according to
which ever switch is in on position.
Protoboard Application

7. Troubleshooting and Improvement
There are not really any inherit issues with the design since it’s quite simple and straight
forward. Improvement that could be made to the design is that the switches could be changed to
smaller DIPs switches, bigger LEDs for better viewing.
Conclusion
This project has helped myself demonstrate the use of a simple circuit that can be
controlled by an Arduino.

8. Work Cited
https://circuits.io/circuits/3731694-et-320-assignment-1-led-and-dips-switches#breadboard –
Circuits and schematics
"Learn About LED Bulbs." ENERGY STAR. N.p., n.d. Web. 01 Feb. 2017.
"What Is Dip Switch?" What Is Dip Switch? N.p., n.d. Web. 01 Feb. 2017.