Arduino 1

ARDUINO 1Under Development

Arduino Arduino is an open-source electronics

prototyping platform based on flexible, easy-to-use hardware and software.

It's intended for artists, designers, hobbyists, and anyone interested in creating interactive

objects or environments. http://www.arduino.cc/

Arduino Arduino can sense the environment by

receiving input from a variety of sensors and can affect its surroundings by controlling

lights, motors, and other actuators. The microcontroller on the board is

programmed using the Arduino programming language (based on Wiring) and the Arduino development environment (based on Processing).

http://www.arduino.cc/

Arduino Arduino projects can be stand-alone or

they can communicate with software on running on a computer (e.g. Flash, Processing, MaxMSP).

http://www.arduino.cc/

Download the latest version from the page: http://arduino.cc/en/Main/Software Download the latest version from the page: http://www.ftdichip.com/Drivers/VCP.htm

Basics In the Arduino environment programs

are referred to as sketches http://www.arduino.cc/ http://arduino.cc/en/Reference/

HomePage http://arduino.cc/en/Tutorial/Foundations

Basics Comments

/* * Blink * * The basic Arduino example. Turns on an LED on for one second, * then off for one second, and so on... We use pin 13 because, * depending on your Arduino board, it has either a built-in LED * or a built-in resistor so that you need only an LED. * * http://www.arduino.cc/en/Tutorial/Blink */

// LED connected to digital pin 13

Digital / Analog

Power The Arduino Duemilanove can be powered via

the USB connection or with an external power supply. The power source is selected automatically. The Arduino Diecimila requires the user to select the power option with a jumper

External (non-USB) power can come either from an AC-to-DC adapter (wall-wart) or battery. The adapter can be connected by plugging a 2.1 mm center-positive plug into the board's power jack. Leads from a battery can be inserted in the Gnd and Vin pin headers of the POWER connector

Power The board can operate on an external

supply of 6 to 20 volts. If supplied with less than 7 V, however, the 5 V pin may supply less than five volts and the board may be unstable. If using more than 12 V, the voltage regulator may overheat and damage the board.

The recommended range is 7 to 12 volts.

The power pins are as follows: •Vin. The input voltage to the Arduino board when it's using an external power source (as opposed to 5 volts from the USB connection or other regulated power source). You can supply voltage through this pin, or, if supplying voltage via the power jack, access it through this pin. •5V. The regulated power supply used to power the microcontroller and other components on the board. This can come either from Vin via an on-board regulator, or be supplied by USB or another regulated 5V supply. •3V3. A 3.3 volt supply generated by the on-board FTDI chip. Maximum current draw is 50 mA. •GND. Ground pins.

Power connector

USB connector

Vin5V output3V3 output

Arduino Microcontroller Boards12

Arduino Microcontroller Boards

Microcontroller ATmega328 Operating Voltage 5 V Input Voltage (recommended) 7-12 V Input Voltage (limits) 6-20 V Digital I/O Pins 14 (of which 6 provide PWM output)Analog Input Pins 6DC Current per I/O Pin 40 mA DC Current for 3.3V Pin 50 mAFlash Memory 32 KB (ATmega328) of which 2 KB used by bootloader SRAM 2 KB (ATmega328)EEPROM 1 KB (ATmega328)Clock Speed 16 MHz

13

breadboards A breadboard is used to

make up temporary circuits for testing or to try out an idea.

No soldering is required so it is easy to change connections and replace components.

Parts will not be damaged so they will be available to re-use afterwards.

http://www.kpsec.freeuk.com/breadb.htm

Basic Programming Declare variables at top setup() and loop()

There are two special functions that are a part of every Arduino sketch: setup() and loop(). The setup() is called once, when the sketch

starts. It's a good place to do setup tasks like setting pin modes or initializing libraries.

The loop() function is called over and over and is heart of most sketches.

You need to include both functions in your sketch, even if you don't need them for anything.

Basic Programming void setup() { }

void loop() { }

/* * “Hello World!”

* This is the Hello World! for Arduino. * It shows how to send data to the computer

*/void setup() // run once, when the sketch starts{

Serial.begin(9600); // set up Serial library at 9600 bps

Serial.println("Is anybody out there?"); // prints phrase with ending line break

}

void loop() // run over and over again{

// do nothing!}// After sending program to the Arduino, press Reset button on the board

and watch Serial monitor

Basic Programming The pinMode() function configures a pin as

either an input or an output. To use it: You pass it the number of the pin to configure

and the constant INPUT or OUTPUT. pinMode(11, INPUT); pinMode(13, OUTPUT); 

When configured as an input, a pin can detect the state of a sensor like a pushbutton.

As an output, it can drive an actuator like an LED.

Basic Programming The digitalWrite() functions outputs a

value on a pin. Possible values are:

LOW (0 V)or HIGH (5 V)

For example: digitalWrite(13, HIGH); digitalWrite(11, LOW);

Basic Programming The delay() causes the Arduino to wait

for the specified number of milliseconds before continuing on to the next line.

There are 1000 milliseconds in a second, so the line: delay(1000);

creates a delay of one second.

Blink The boards are designed to make it easy to blink an LED using

digital pin 13. Some (like the Diecimila and LilyPad) have the LED built-in to the board. On most others (like the Mini and BT), there is a 1 KB resistor on the pin, allowing you to connect an LED directly.

int ledPin = 13; // LED connected to digital pin 13

// The setup() method runs once, when the sketch starts

void setup() { // initialize the digital pin as an output: pinMode(ledPin, OUTPUT); }

// the loop() method runs over and over again,// as long as the Arduino has power

void loop() { digitalWrite(ledPin, HIGH); // set the LED on delay(1000); // wait for a second digitalWrite(ledPin, LOW); // set the LED off delay(1000); // wait for a second}

http://arduino.cc/en/Tutorial/Blink

Variables You can use variables in a similar way as

they are used in math or physics All variables have to be declared before

they are used , and optionally, set an initial value (initializing the

variable).

char A data type that takes up 1 byte of memory that

stores a character value. Character literals are written in single quotes, like this: 'A' (for multiple characters - strings - use double quotes: "ABC").

Characters are stored as numbers however. You can see the specific encoding in the ASCII chart.

ASCII Table

char

The char datatype is a signed type, meaning that it encodes numbers from -128 to 127. For an unsigned, one-byte (8 bit) data type, use the byte data type.

Example char myChar = 'A'; char myChar = 65; // both are

equivalent

char It is possible to do arithmetic on characters, in

which the ASCII value of the character is used (e.g. 'A' + 1 has the value 66, since the ASCII value of the capital letter A is 65). See Serial.println reference for more on how characters are translated to numbers.

byte A byte stores an 8-bit unsigned number,

from 0 to 255. Example byte b = B10010; // "B" is the binary

formatter (B10010 = 18 decimal)

int Integers are your primary datatype for

number storage, and store a 2 byte value. This yields a range of -32,768 to 32,767 (minimum value of -2^15 and a maximum value of (2^15) - 1).

Int's store negative numbers with a technique called 2's complement math. The highest bit, sometimes refered to as the "sign" bit, flags the number as a negative number. The rest of the bits are inverted and 1 is added.

int Example int ledPin = 13;

Syntax int var = val;

unsigned int Unsigned ints (unsigned integers)

are the same as ints in that they store a 2 byte value. Instead of storing negative numbers however they only store positive values, yielding a useful range of 0 to 65,535 (2^16) - 1).

unsigned int Example unsigned int ledPin = 13;

Syntax unsigned int var = val;

var - your unsigned int variable name val - the value you assign to that variable

long long – long variables are extended size

variables for number storage, and store 32 bits (4 bytes), from −2,147,483,648 to 2,147,483,647.

unsigned long – unsigned long variables are extended size variables for number storage, and store 32 bits (4 bytes). Unlike standard longs unsigned longs won't store negative numbers, making their range from 0 to 4,294,967,295

float / double

7. float – datatype for floating-point numbers, a number that has a decimal point. They are often used to approximate analog and continuous values because they have greater resolution than integers. Floating-point numbers can be as large as 3.4028235E+38 and as low as −3.4028235E+38. They are stored as 32 bits (4 bytes) of information.

8. double – double precision floating point number. Occupies 4 bytes. The double implementation on the Arduino is currently exactly the same as the float, with no gain in precision.

Lots of useful functions pinMode() – set a pin as input or output digitalWrite() – set a digital pin high/low digitalRead() – read a digital pin’s state analogRead() – read an analog pin analogWrite() – write an “analog” PWM value delay() – wait an amount of time (ms) millis() – get the current time

Traffic Light ControlInt ledRed = 13;

int ledGreen = 11;int ledYellow = 12;

void setup(){  pinMode(ledRed, OUTPUT);      // sets the digital pin as output  pinMode(ledYellow, OUTPUT);      // sets the digital pin as output  pinMode(ledGreen, OUTPUT);      // sets the digital pin as output}

void loop(){  digitalWrite(ledGreen, HIGH);   // sets the Green LED on  delay(1000);                  // waits for a second  digitalWrite(ledGreen, LOW);    // sets the Green LED off  digitalWrite(ledYellow,HIGH);   // sets the Yellow LED on  delay(1000);                  // waits for a second  digitalWrite(ledYellow, LOW);    // sets the Yellow LED off  digitalWrite(ledRed, HIGH);   // sets the Red LED on  delay(1000);                  // waits for a second  digitalWrite(ledRed, LOW);    // sets the Reed LED off}

If / else if/else allows greater control over the flow of code than the basic

if statement, by allowing multiple tests to be grouped together. For example, an analog input could be tested and one action taken if the input was less than 500, and another action taken if the input was 500 or greater. The code would look like this:

if (Comparison) { // action A (Comparison true) } else { // action B (Comparison false) }

Comparison Operators x < y (x is less than y) x > y (x is greater than y) x <= y (x is less than or equal to y) x >= y (x is greater than or equal to y) x == y (x is equal to y) x != y (x is not equal to y)

Button Pushbuttons or

switches connect two points in a circuit when you press them. This example turns on the built-in LED on pin 13 when you press the button.

int buttonPin = 2; // the number of the pushbutton pinint ledPin = 13; // the number of the LED pinint buttonState = 0; // variable for reading the pushbutton status

void setup() { pinMode(ledPin, OUTPUT); // initialize the LED pin as an output: pinMode(buttonPin, INPUT); // initialize the pushbutton pin as an input: }

void loop(){ buttonState = digitalRead(buttonPin); // read the state of the pushbutton value:

if (buttonState == HIGH) { // check if the pushbutton is pressed. If it is, the buttonState is HIGH: digitalWrite(ledPin, HIGH); // turn LED on: } else { digitalWrite(ledPin, LOW); // turn LED off: }}

Button The problem with the last program is

that the switch has to remain pressed in order for the LED to turn on

We want the LED to change state when we press the button and to stay in the new state when the button is released

int buttonPin = 2; // the pin that the pushbutton is attached toint ledPin = 13; // the pin that the LED is attached toint buttonState = 0; // current state of the buttonint lastLEDState = 0; // previous state of the button

void setup() { pinMode(buttonPin, INPUT); // initialize the button pin as a input: pinMode(ledPin, OUTPUT); // initialize the LED as an output:}

void loop() { buttonState = digitalRead(buttonPin); // read the pushbutton input pin: if (buttonState == HIGH) { // Determine if button State is HIGH if (lastLEDState == HIGH) { // if the current state is HIGH then turn LED off digitalWrite(ledPin, LOW); lastLEDState = LOW; } else {// if the current state is LOW then turn LED on digitalWrite(ledPin, HIGH); lastLEDState = HIGH; } while(buttonState == HIGH){ buttonState = digitalRead(buttonPin); // read the pushbutton input pin: }; delay(250); } }

Arithmetic Operators Arithmetic operators include addition,

subtraction, multiplication, and division. They return the sum, difference, product, or quotient of two operands.

y = y + 3;x = x - 7;i = j * 6;r = r / 5;

/* Math */

int a = 5;

int b = 10;

int c = 20;

void setup()

{

Serial.begin(9600); // set up Serial library at 9600 bps

Serial.println("Here is some math: ");

Serial.print("a = ");

Serial.println(a);

Serial.print("b = ");

Serial.println(b);

Serial.print("c = ");

Serial.println(c);

Serial.print("a + b = "); // add

Serial.println(a + b);

Serial.print("a * c = "); // multiply

Serial.println(a * c);

Serial.print("c / b = "); // divide

Serial.println(c / b);

Serial.print("b - c = "); // subtract

Serial.println(b - c);

}

void loop() // we need this to be here even though its empty

{

}

Run this program.

What do you see on the Serial Monitor?

Replace format “int” with “float”

Run this program again.

What do you see on the Serial Monitor?

distance = 32/voltageGood for voltage < 2.6 V,distance > 10 cm

Voltage measurement int analogRead(pin) Description

Reads the value from the specified analog pin. The Arduino board contains a 6 channel (8 channels on the Mini and Nano), 10-bit analog to digital converter. This means that it will map input voltages between 0 and 5 volts into integer values between 0 and 1023. This yields a resolution between readings of: 5 volts / 1024 units or, .0049 volts (4.9 mV) per unit. It takes about 100 us (0.0001 s) to read an analog input, so the maximum reading rate is about 10,000 times a second.

Voltage measurementunsigned int voltage1, distance1;int sensor1 = 0;void setup(){ Serial.begin(9600); // setup serial}void loop(){ voltage1 = analogRead(sensor1); Serial.println(voltage1); // debug value delay(1000);}

Music (http://arduino.cc/en/Tutorial/Melody) The calculation of the tones is made following the mathematical

operation: timeHigh = period / 2 = 1 / (2 * toneFrequency) where the different tones are described as in the table: note frequency period timeHigh c 261 Hz 3830 1915 d 294 Hz 3400 1700 e 329 Hz 3038 1519 f 349 Hz 2864 1432 g 392 Hz 2550 1275 a 440 Hz 2272 1136 b 493 Hz 2028 1014 C 523 Hz 1912 956

#include "pitches.h"

int speakerPin = 11;int length = 15; // the number of notesint melody[] = {C4, C4, G4, G4, A4, A4, G4, F4, F4, E4, E4, D4, D4, C4, P}; // P represents a restint beats[] = { 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 4 };int tempo = 300;

void setup() {pinMode(speakerPin, OUTPUT);}void loop() {for (int i = 0; i < length; i++) {tone(speakerPin, melody[i],beats[i]*tempo);delay(beats[i]*tempo + tempo / 2); // pause between notes}}

Download and install under Arduino libraries

Pitches

/************************************************* * Public Constants *************************************************/

#define P 0#define B0 31#define C1 33#define CS1 35#define D1 37#define DS1 39#define E1 41#define F1 44#define FS1 46#define G1 49#define GS1 52#define A1 55#define AS1 58#define B1 62#define C2 65#define CS2 69#define D2 73

int speakerPin = 11;int length = 15; // the number of noteschar notes[] = "ccggaagffeeddc "; // a space

represents a restint beats[] = { 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 2, 4 };int tempo = 300;void playTone(int tone, int duration) { for (long i = 0; i < duration * 1000L; i += tone * 2) { digitalWrite(speakerPin, HIGH); delayMicroseconds(tone); digitalWrite(speakerPin, LOW); delayMicroseconds(tone); }}void playNote(char note, int duration) { char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C' }; int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136,

1014, 956 }; // play the tone corresponding to the note name for (int i = 0; i < 8; i++) { if (names[i] == note) { playTone(tones[i], duration); } }}

void setup() { pinMode(speakerPin, OUTPUT);}void loop() { for (int i = 0; i < length; i++) { if (notes[i] == ' ') { delay(beats[i] * tempo); //

rest } else { playNote(notes[i], beats[i] *

tempo); } // pause between notes delay(tempo / 2); }}