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Introduction to Arduino

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Setup

– Arduino IDE Downloadhttps://www.arduino.cc/en/Main/Software

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What is Arduino?

• Arduino is an open-source prototyping platform based on easy to use hardware and software

• There are many different types of Arduino of different capabilities– Uno, Pro, Gemma, Mega...

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Circuits

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Terminology

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Terminology-Hardware

Output pin - Provides current to the circuit, if the programming asks for it

Input pin - Reads whether the circuit is providing HIGH or LOW current

3.3V/5V - A special type of pin that always provides current, regardless of programming

Ground(GND) - Where the current will flow back into the board after it’s done with the circuit

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Terminology-Software

Setup- This part of the code only runs ONCE. This is where you can define variables and designate pins as input or output

Loop- This part of the code runs repeatedly, forever, until your program is stopped

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Breadboards

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• Make a basic circuit with a blinking LED

• Learn how to program pins on the Arduino

Example 1: Blinking an LED

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Schematic

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pinMode(13, OUTPUT);

• Sets pin 13 as an output pin• Put this in the setup

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digitalWrite(13, HIGH);

• Sets pin 13 to provide high current (turns on LED)

• Put this in your loop

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delay(1000);

• Delays the program (pauses it) for 1000 milliseconds (1 second)

• Put this in your loop

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digitalWrite(13, LOW);

• Sets pin 13 to provide no current (turns off LED)

• Put this in your loop

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void setup() {pinMode(13, OUTPUT);

}

void loop() {digitalWrite(13, HIGH); delay(1000); digitalWrite(13, LOW); delay(1000);

}

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Potentiometer

• A potentiometer is also known as a variable resistor

• Able to return a voltage between 0 and 5 volts from its middle pin – depending on the position of the

knob

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Digital Vs. Analog

• Digital– Only two states, HIGH(5V) or LOW(0V)

• Analog– Translates an input voltage to a

range of values from 0-1023• 0V at 0 and 5V at 1023

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Variables

• Variable - a memory location with a name and type that stores a value

• int num; -> Declaration (request to set aside a new variable with a given name and type)

num = 3; -> Assignment Statement (assign a value to the variable)

• int num = 3; -> you can combine both steps into 1 statement

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Schematic

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Blinking LEDs with Potentiometer

– Blinking

• Use the potentiometer readings to

increase or decrease the gap between the next time you turn on the LED

– Commands• analogRead(sensorPin);

– reads the value (0-1023) of the analog pin

given the sensor pin

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Blinking LED w/ Potentiometer Code

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Buttons

• Simplest way to receive user input– When button is pushed voltage goes to

ground to arduino reads as LOW

– Use the 10K pullup resistor to reduce amount of false positive button presses

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If/Else Statements

if(condition){//do something

}else if(condition 2){

//do something else}else{

//so some third thing}

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If/Else Statements

Comparators: ==, !=, &&, ||, !

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On/Off Buttons

• Let’s make a program where one button turns on an LED and another turns it off

• Commands– pinMode(buttonPin, INPUT);– digitalRead(buttonPin);

• read the voltage present at the pin, either HIGH(5V) or LOW(0V)

– conditionals

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Schematic

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On/Off Buttons Code

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Challenge: 2 LEDs

• Create a program that turns an led on when it’s respective button is pressed– You need 2 LED’s controlled by 1

button each

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2 LEDs Solution Codeint button1Pin = 0;int button2Pin = 1;int led1Pin = 13;int led2Pin = 12;void setup() { // put your setup code here, to run once: pinMode(button1Pin, INPUT); pinMode(button2Pin, INPUT); pinMode(led1Pin, OUTPUT); pinMode(led2Pin, OUTPUT);}void loop() { // put your main code here, to run repeatedly: int button1State, button2State; //variables to hold the button states button1State = digitalRead(button1Pin); //read the inputs button2State = digitalRead(button2Pin); if(button1State == LOW){ //if button1 is pressed turn on LED1 digitalWrite(led1Pin, HIGH); } else{ //otherwise turn off the LED digitalWrite(led1Pin, LOW); } if(button2State == LOW){ //if button2 is pressed turn on LED2 digitalWrite(led2Pin, HIGH); } else{ //otherwise turn off the LED digitalWrite(led2Pin, LOW); }}

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Servos

• A servo is a type of electric motor that allows for precise angular motion– Servos will hold their given

position unlike motors which may continue to rotate

• Red=power• Black=ground• Yellow=control

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Schematic

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Moving the servo

• Commands– #include <Servo.h>

• inserts the Servo library into the code– Servo servo1;

• create a “new” servo in the code– servo1.attach(servoPin);

• set the digital pin the servo is attached to

– servo1.write(pos);• servos can move to a specific position

between 0 and 180 degrees• make sure to give the servo a short delay

so it has time to make the move

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Basic Servo Code

#include <Servo.h>

Servo myservo;

int pos = 0; // variable to store the servo position

void setup() {

myservo.attach(9); // attaches the servo on pin 9 to the servo object

}

void loop() {

myservo.write(180);

delay(1000);

myservo.write(0);

delay(1000);

}

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Challenge: Servo+Potentiometer

• Create a program that makes the servo turn when you turn the potentiometer.

• map(var, currentLow, currentHigh, newLow, newHigh);

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Servo+Potentiometer Solution Code

#include <Servo.h>

Servo myservo;

int sensorPin=0;

void setup() {

myservo.attach(9); // attaches the servo on pin 9 to the servo object

}

void loop() {

int sensorValue = analogRead(sensorPin); //recieve the potentiometer value

sensorValue = map(sensorValue, 0, 1023, 0, 180); //scale the potentiometer reading to a possible servo value

myServo.write(sensorValue); // write the position to the servo

delay(15);

}

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Intro to Arduino

Thanks for Coming!Visit our website if you are interested in signing up for more classes!

Web Resources:

• https://www.arduino.cc/

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