by Anson Fu for NTU Biomedical Engineering Society
This workshop is based on ARDUINO IDE 1.8.5, ARDUINO UNO R3 Board and assumes basic knowledge of C++ Language and electronic protot.
Disclaimer - This document is only meant to serve as a reference for the attendees of the workshop. It does not cover all the concepts or implementation details discussed during the actual workshop.
When?: Satauday, 12 May 2018. 2:00 PM - 6:00 PM.
Where?: TR +27, The Hive, Nanyang Technological University
Who?: NTU Biomedical Engineering Society
Number systems are the methods we use to represent numbers. Binary just uses two digits, 0 and 1. Binary is also known as a base-2 number system.
In the base-10 number system, each digit represents a value of 10x, where X is the digit
placement from the right, starting from zero and multiplying by that digit value. For example,
123 in decimal is:
1×10^2+3×10^1+3×10^0=123.
123 in binary would be:
1×2^6+1×2^5+1×2^4+1×2^3+0×2^2+1×2^1+1×2^0=123.
Let's create a counter that counts in binary.
int button = 2; //set to correct pin
int presses = 0;
long time = 0;
long debounce = 100;
const byte numPins = 3; //number of pins we use
byte LEDpins[] = {3, 4, 5}; //set to correct pins
void setup() {
Serial.begin(9600);
for(int i = 0; i < numPins; i++) {
pinMode(LEDpins[i], OUTPUT);
}
pinMode(button, INPUT_PULLUP); //monitors the state of a switch
attachInterrupt(0, count, LOW); //function count is triggerd when pin 0 is LOW
}
void loop() {
String binNumber = String(presses, BIN); //give a string of binary number
int binLength = binNumber.length(); //get the length from binary number
boolean led0 = binNumber.charAt(binNumber.length()-1)=='1'; //search for '1' at specific location, true when '1' is found
boolean led1 = binNumber.charAt(binNumber.length()-2)=='1';
boolean led2 = binNumber.charAt(binNumber.length()-3)=='1';
if(presses <= 7) {
digitalWrite(LEDpins[0],led0);
digitalWrite(LEDpins[1],led1);
digitalWrite(LEDpins[2],led2);
} else {
presses = 0;
}
}
void count() {
if(millis() - time > debounce){
presses++;
}
time = millis();
}
If your Arduino application only needs to display numbers, consider using a seven-segment display. The severn-segment display has seven LEDs arranged in the shape of number eight. They are easy to use and cost effective. The picture below shows a typical seven-segment display.

Seven segment displays are of two types: common anode and common cathode. The Internal structure of both types is nearly the same. The difference is the polarity of the LEDs and common terminal.
In a common cathode seven-segment display, all seven LEDs plus a dot LED have the cathodes connected to pins 2 and pin 8. To use this display, we need to connect GROUND to pin 2 and pin 8 and, and connect +5V to the other pins to make the individual segments light up.

The common anode display is the exact opposite. In a common-anode display, the positive terminal of all the eight LEDs are connected together and then connected to pin 3 and pin 8. To turn on an individual segment, you ground one of the pins.
The seven segment are labelled a-g, with the dot being "dp," as shown in the figure below:
To display a particular number, you turn on the individual segments as shown in the table below:
In this experiment, we will simply turn on and turn off the LEDs to get familiar with how a seven-segment display works.
void setup()
{
// define pin modes
pinMode(2,OUTPUT);
pinMode(3,OUTPUT);
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
pinMode(6,OUTPUT);
pinMode(7,OUTPUT);
pinMode(8,OUTPUT);
}
void loop()
{
// loop to turn leds od seven seg ON
for(int i=2;i<9;i++)
{
digitalWrite(i,HIGH);
delay(600);
}
// loop to turn leds od seven seg OFF
for(int i=2;i<9;i++)
{
digitalWrite(i,LOW);
delay(600);
}
delay(1000);
}In this experiment, we will turn on specific LEDs to show numbers.
#define segA 2//connecting segment A to PIN2
#define segB 3// connecting segment B to PIN3
#define segC 4// connecting segment C to PIN4
#define segD 5// connecting segment D to PIN5
#define segE 6// connecting segment E to PIN6
#define segF 7// connecting segment F to PIN7
#define segG 8// connecting segment G to PIN8
void setup()
{
for (int i=2;i<9;i++) {
pinMode(i, OUTPUT);// taking all pins from 2-8 as output
}
}
void loop()
{ // To show number 0
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, HIGH);
digitalWrite(segF, HIGH);
digitalWrite(segG, LOW);
}In this experiment, we will count up numbers.
#define segA 2//connecting segment A to PIN2
#define segB 3// connecting segment B to PIN3
#define segC 4// connecting segment C to PIN4
#define segD 5// connecting segment D to PIN5
#define segE 6// connecting segment E to PIN6
#define segF 7// connecting segment F to PIN7
#define segG 8// connecting segment G to PIN8
int COUNT=0;//count integer for 0-9 increment
void setup()
{
for (int i=2;i<9;i++) {
pinMode(i, OUTPUT);// taking all pins from 2-8 as output
}
}
void loop()
{
switch(COUNT)
{
case 0://when count value is zero show”0” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, HIGH);
digitalWrite(segF, HIGH);
digitalWrite(segG, LOW);
break;
case 1:// when count value is 1 show”1” on disp
digitalWrite(segA, LOW);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, LOW);
digitalWrite(segE, LOW);
digitalWrite(segF, LOW);
digitalWrite(segG, LOW);
break;
case 2:// when count value is 2 show”2” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, LOW);
digitalWrite(segD, HIGH);
digitalWrite(segE, HIGH);
digitalWrite(segF, LOW);
digitalWrite(segG, HIGH);
break;
case 3:// when count value is 3 show”3” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, LOW);
digitalWrite(segF, LOW);
digitalWrite(segG, HIGH);
break;
case 4:// when count value is 4 show”4” on disp
digitalWrite(segA, LOW);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, LOW);
digitalWrite(segE, LOW);
digitalWrite(segF, HIGH);
digitalWrite(segG, HIGH);
break;
case 5:// when count value is 5 show”5” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, LOW);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, LOW);
digitalWrite(segF, HIGH);
digitalWrite(segG, HIGH);
break;
case 6:// when count value is 6 show”6” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, LOW);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, HIGH);
digitalWrite(segF, HIGH);
digitalWrite(segG, HIGH);
break;
case 7:// when count value is 7 show”7” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, LOW);
digitalWrite(segE, LOW);
digitalWrite(segF, LOW);
digitalWrite(segG, LOW);
break;
case 8:// when count value is 8 show”8” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, HIGH);
digitalWrite(segF, HIGH);
digitalWrite(segG, HIGH);
break;
case 9:// when count value is 9 show”9” on disp
digitalWrite(segA, HIGH);
digitalWrite(segB, HIGH);
digitalWrite(segC, HIGH);
digitalWrite(segD, HIGH);
digitalWrite(segE, LOW);
digitalWrite(segF, HIGH);
digitalWrite(segG, HIGH);
break;
break;
}
if (COUNT<10) {
COUNT++;
delay(1000);///increment count integer for every second
}
if (COUNT==10) {
COUNT=0;// if count integer value is equal to 10, reset it to zero.
delay(1000);
}
}In this experiment, we will count up numbers.
// make an array to save Seven Seg pin configuration of numbers
int num_array[10][7] = { { 1,1,1,1,1,1,0 }, // 0
{ 0,1,1,0,0,0,0 }, // 1
{ 1,1,0,1,1,0,1 }, // 2
{ 1,1,1,1,0,0,1 }, // 3
{ 0,1,1,0,0,1,1 }, // 4
{ 1,0,1,1,0,1,1 }, // 5
{ 1,0,1,1,1,1,1 }, // 6
{ 1,1,1,0,0,0,0 }, // 7
{ 1,1,1,1,1,1,1 }, // 8
{ 1,1,1,0,0,1,1 }}; // 9
//function header
void Num_Write(int);
void setup()
{
// set pin modes
pinMode(2, OUTPUT);
pinMode(3, OUTPUT);
pinMode(4, OUTPUT);
pinMode(5, OUTPUT);
pinMode(6, OUTPUT);
pinMode(7, OUTPUT);
pinMode(8, OUTPUT);
}
void loop()
{
//counter loop
for (int counter = 10; counter > 0; --counter)
{
delay(1000);
Num_Write(counter-1);
}
delay(3000);
}
// this functions writes values to the sev seg pins
void Num_Write(int number)
{
int pin= 2;
for (int j=0; j < 7; j++) {
digitalWrite(pin, num_array[number][j]);
pin++;
}
}In this tutorial, we are going to Interface piezo buzzer or piezo speaker with Arduino UNO. A piezo buzzer is generally used to signal user in the form of tone or beep. This type of buzzer widely used in alarm, domestic gadgets or in embedded systems product to provide some kind of indication or alert.Buy designing a small circuit we can interface it easily with Arduino. We will design a small transistorized circuit and by providing high signal we can get a tone signal from the piezo buzzer.

const int buzzer = 9; //buzzer to arduino pin 9
void setup(){
pinMode(buzzer, OUTPUT); // Set buzzer - pin 9 as an output
}
void loop(){
tone(buzzer, 1000); // Send 1KHz sound signal...
delay(1000); // ...for 1 sec
noTone(buzzer); // Stop sound...
delay(1000); // ...for 1sec
}// TONES ==========================================
// Start by defining the relationship between
// note, period, & frequency.
#define c 3830 // 261 Hz
#define d 3400 // 294 Hz
#define e 3038 // 329 Hz
#define f 2864 // 349 Hz
#define g 2550 // 392 Hz
#define a 2272 // 440 Hz
#define b 2028 // 493 Hz
#define C 1912 // 523 Hz
// Define a special note, 'R', to represent a rest
#define R 0
// SETUP ============================================
// Set up speaker on a PWM pin
int speakerOut = 9;
// Do we want debugging on serial out? 1 for yes, 0 for no
int DEBUG = 1;
void setup() {
pinMode(speakerOut, OUTPUT);
if (DEBUG) {
Serial.begin(9600); // Set serial out if we want debugging
}
}
// MELODY and TIMING =======================================
// melody[] is an array of notes, accompanied by beats[],
// which sets each note's relative length (higher #, longer note)
int melody[] = { C, b, g, C, b, e, R, C, c, g, a, C };
int beats[] = { 16, 16, 16, 8, 8, 16, 32, 16, 16, 16, 8, 8 };
int MAX_COUNT = sizeof(melody) / 2; // Melody length, for looping.
// Set overall tempo
long tempo = 10000;
// Set length of pause between notes
int pause = 1000;
// Loop variable to increase Rest length
int rest_count = 100; //<-BLETCHEROUS HACK; See NOTES
// Initialize core variables
int tone_ = 0;
int beat = 0;
long duration = 0;
// PLAY TONE ==============================================
// Pulse the speaker to play a tone for a particular duration
void playTone() {
long elapsed_time = 0;
if (tone_ > 0) { // if this isn't a Rest beat, while the tone has
// played less long than 'duration', pulse speaker HIGH and LOW
while (elapsed_time < duration) {
digitalWrite(speakerOut,HIGH);
delayMicroseconds(tone_ / 2);
// DOWN
digitalWrite(speakerOut, LOW);
delayMicroseconds(tone_ / 2);
// Keep track of how long we pulsed
elapsed_time += (tone_);
}
}
else { // Rest beat; loop times delay
for (int j = 0; j < rest_count; j++) { // See NOTE on rest_count
delayMicroseconds(duration);
}
}
}
// LET THE WILD RUMPUS BEGIN =============================
void loop() {
// Set up a counter to pull from melody[] and beats[]
for (int i=0; i<MAX_COUNT; i++) {
tone_ = melody[i];
beat = beats[i];
duration = beat * tempo; // Set up timing
playTone();
// A pause between notes...
delayMicroseconds(pause);
if (DEBUG) { // If debugging, report loop, tone, beat, and duration
Serial.print(i);
Serial.print(":");
Serial.print(beat);
Serial.print(" ");
Serial.print(tone_);
Serial.print(" ");
Serial.println(duration);
}
}
}/*
Arduino Mario Bros Tunes
With Piezo Buzzer and PWM
Connect the positive side of the Buzzer to pin 3,
then the negative side to a 1k ohm resistor. Connect
the other side of the 1 k ohm resistor to
ground(GND) pin on the Arduino.
by: Dipto Pratyaksa
last updated: 31/3/13
*/
/*************************************************
* Public Constants
*************************************************/
#define NOTE_B0 31
#define NOTE_C1 33
#define NOTE_CS1 35
#define NOTE_D1 37
#define NOTE_DS1 39
#define NOTE_E1 41
#define NOTE_F1 44
#define NOTE_FS1 46
#define NOTE_G1 49
#define NOTE_GS1 52
#define NOTE_A1 55
#define NOTE_AS1 58
#define NOTE_B1 62
#define NOTE_C2 65
#define NOTE_CS2 69
#define NOTE_D2 73
#define NOTE_DS2 78
#define NOTE_E2 82
#define NOTE_F2 87
#define NOTE_FS2 93
#define NOTE_G2 98
#define NOTE_GS2 104
#define NOTE_A2 110
#define NOTE_AS2 117
#define NOTE_B2 123
#define NOTE_C3 131
#define NOTE_CS3 139
#define NOTE_D3 147
#define NOTE_DS3 156
#define NOTE_E3 165
#define NOTE_F3 175
#define NOTE_FS3 185
#define NOTE_G3 196
#define NOTE_GS3 208
#define NOTE_A3 220
#define NOTE_AS3 233
#define NOTE_B3 247
#define NOTE_C4 262
#define NOTE_CS4 277
#define NOTE_D4 294
#define NOTE_DS4 311
#define NOTE_E4 330
#define NOTE_F4 349
#define NOTE_FS4 370
#define NOTE_G4 392
#define NOTE_GS4 415
#define NOTE_A4 440
#define NOTE_AS4 466
#define NOTE_B4 494
#define NOTE_C5 523
#define NOTE_CS5 554
#define NOTE_D5 587
#define NOTE_DS5 622
#define NOTE_E5 659
#define NOTE_F5 698
#define NOTE_FS5 740
#define NOTE_G5 784
#define NOTE_GS5 831
#define NOTE_A5 880
#define NOTE_AS5 932
#define NOTE_B5 988
#define NOTE_C6 1047
#define NOTE_CS6 1109
#define NOTE_D6 1175
#define NOTE_DS6 1245
#define NOTE_E6 1319
#define NOTE_F6 1397
#define NOTE_FS6 1480
#define NOTE_G6 1568
#define NOTE_GS6 1661
#define NOTE_A6 1760
#define NOTE_AS6 1865
#define NOTE_B6 1976
#define NOTE_C7 2093
#define NOTE_CS7 2217
#define NOTE_D7 2349
#define NOTE_DS7 2489
#define NOTE_E7 2637
#define NOTE_F7 2794
#define NOTE_FS7 2960
#define NOTE_G7 3136
#define NOTE_GS7 3322
#define NOTE_A7 3520
#define NOTE_AS7 3729
#define NOTE_B7 3951
#define NOTE_C8 4186
#define NOTE_CS8 4435
#define NOTE_D8 4699
#define NOTE_DS8 4978
#define melodyPin 9
//Mario main theme melody
int melody[] = {
NOTE_E7, NOTE_E7, 0, NOTE_E7,
0, NOTE_C7, NOTE_E7, 0,
NOTE_G7, 0, 0, 0,
NOTE_G6, 0, 0, 0,
NOTE_C7, 0, 0, NOTE_G6,
0, 0, NOTE_E6, 0,
0, NOTE_A6, 0, NOTE_B6,
0, NOTE_AS6, NOTE_A6, 0,
NOTE_G6, NOTE_E7, NOTE_G7,
NOTE_A7, 0, NOTE_F7, NOTE_G7,
0, NOTE_E7, 0, NOTE_C7,
NOTE_D7, NOTE_B6, 0, 0,
NOTE_C7, 0, 0, NOTE_G6,
0, 0, NOTE_E6, 0,
0, NOTE_A6, 0, NOTE_B6,
0, NOTE_AS6, NOTE_A6, 0,
NOTE_G6, NOTE_E7, NOTE_G7,
NOTE_A7, 0, NOTE_F7, NOTE_G7,
0, NOTE_E7, 0, NOTE_C7,
NOTE_D7, NOTE_B6, 0, 0
};
//Mario main them tempo
int tempo[] = {
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
9, 9, 9,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
9, 9, 9,
12, 12, 12, 12,
12, 12, 12, 12,
12, 12, 12, 12,
};
//Underworld melody
int underworld_melody[] = {
NOTE_C4, NOTE_C5, NOTE_A3, NOTE_A4,
NOTE_AS3, NOTE_AS4, 0,
0,
NOTE_C4, NOTE_C5, NOTE_A3, NOTE_A4,
NOTE_AS3, NOTE_AS4, 0,
0,
NOTE_F3, NOTE_F4, NOTE_D3, NOTE_D4,
NOTE_DS3, NOTE_DS4, 0,
0,
NOTE_F3, NOTE_F4, NOTE_D3, NOTE_D4,
NOTE_DS3, NOTE_DS4, 0,
0, NOTE_DS4, NOTE_CS4, NOTE_D4,
NOTE_CS4, NOTE_DS4,
NOTE_DS4, NOTE_GS3,
NOTE_G3, NOTE_CS4,
NOTE_C4, NOTE_FS4, NOTE_F4, NOTE_E3, NOTE_AS4, NOTE_A4,
NOTE_GS4, NOTE_DS4, NOTE_B3,
NOTE_AS3, NOTE_A3, NOTE_GS3,
0, 0, 0
};
//Underwolrd tempo
int underworld_tempo[] = {
12, 12, 12, 12,
12, 12, 6,
3,
12, 12, 12, 12,
12, 12, 6,
3,
12, 12, 12, 12,
12, 12, 6,
3,
12, 12, 12, 12,
12, 12, 6,
6, 18, 18, 18,
6, 6,
6, 6,
6, 6,
18, 18, 18, 18, 18, 18,
10, 10, 10,
10, 10, 10,
3, 3, 3
};
void setup(void)
{
pinMode(9, OUTPUT);//buzzer
pinMode(13, OUTPUT);//led indicator when singing a note
}
void loop()
{
//sing the tunes
sing(1);
sing(1);
sing(2);
}
int song = 0;
void sing(int s) {
// iterate over the notes of the melody:
song = s;
if (song == 2) {
Serial.println(" 'Underworld Theme'");
int size = sizeof(underworld_melody) / sizeof(int);
for (int thisNote = 0; thisNote < size; thisNote++) {
// to calculate the note duration, take one second
// divided by the note type.
//e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
int noteDuration = 1000 / underworld_tempo[thisNote];
buzz(melodyPin, underworld_melody[thisNote], noteDuration);
// to distinguish the notes, set a minimum time between them.
// the note's duration + 30% seems to work well:
int pauseBetweenNotes = noteDuration * 1.30;
delay(pauseBetweenNotes);
// stop the tone playing:
buzz(melodyPin, 0, noteDuration);
}
} else {
Serial.println(" 'Mario Theme'");
int size = sizeof(melody) / sizeof(int);
for (int thisNote = 0; thisNote < size; thisNote++) {
// to calculate the note duration, take one second
// divided by the note type.
//e.g. quarter note = 1000 / 4, eighth note = 1000/8, etc.
int noteDuration = 1000 / tempo[thisNote];
buzz(melodyPin, melody[thisNote], noteDuration);
// to distinguish the notes, set a minimum time between them.
// the note's duration + 30% seems to work well:
int pauseBetweenNotes = noteDuration * 1.30;
delay(pauseBetweenNotes);
// stop the tone playing:
buzz(melodyPin, 0, noteDuration);
}
}
}
void buzz(int targetPin, long frequency, long length) {
digitalWrite(13, HIGH);
long delayValue = 1000000 / frequency / 2; // calculate the delay value between transitions
//// 1 second's worth of microseconds, divided by the frequency, then split in half since
//// there are two phases to each cycle
long numCycles = frequency * length / 1000; // calculate the number of cycles for proper timing
//// multiply frequency, which is really cycles per second, by the number of seconds to
//// get the total number of cycles to produce
for (long i = 0; i < numCycles; i++) { // for the calculated length of time...
digitalWrite(targetPin, HIGH); // write the buzzer pin high to push out the diaphram
delayMicroseconds(delayValue); // wait for the calculated delay value
digitalWrite(targetPin, LOW); // write the buzzer pin low to pull back the diaphram
delayMicroseconds(delayValue); // wait again or the calculated delay value
}
digitalWrite(13, LOW);
}Set Up of Liquid Crystal Display :

// include the library code:
#include <LiquidCrystal.h>
// initialize the library by associating any needed LCD interface pin
// with the arduino pin number it is connected to
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
}
void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis() / 1000);
}
// include the library code:
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
}
void loop() {
// Turn off the blinking cursor:
lcd.noBlink();
delay(3000);
// Turn on the blinking cursor:
lcd.blink();
delay(3000);
}// include the library code:
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
}
void loop() {
// Turn off the display:
lcd.noDisplay();
delay(500);
// Turn on the display:
lcd.display();
delay(500);
}// include the library code:
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
delay(1000);
}
void loop() {
// scroll 13 positions (string length) to the left
// to move it offscreen left:
for (int positionCounter = 0; positionCounter < 13; positionCounter++) {
// scroll one position left:
lcd.scrollDisplayLeft();
// wait a bit:
delay(150);
}
// scroll 29 positions (string length + display length) to the right
// to move it offscreen right:
for (int positionCounter = 0; positionCounter < 29; positionCounter++) {
// scroll one position right:
lcd.scrollDisplayRight();
// wait a bit:
delay(150);
}
// scroll 16 positions (display length + string length) to the left
// to move it back to center:
for (int positionCounter = 0; positionCounter < 16; positionCounter++) {
// scroll one position left:
lcd.scrollDisplayLeft();
// wait a bit:
delay(150);
}
// delay at the end of the full loop:
delay(1000);
}// include the library code:
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
}
void loop() {
// set the cursor to (0,0):
lcd.setCursor(0, 0);
// print from 0 to 9:
for (int thisChar = 0; thisChar < 10; thisChar++) {
lcd.print(thisChar);
delay(500);
}
// set the cursor to (16,1):
lcd.setCursor(16, 1);
// set the display to automatically scroll:
lcd.autoscroll();
// print from 0 to 9:
for (int thisChar = 0; thisChar < 10; thisChar++) {
lcd.print(thisChar);
delay(500);
}
// turn off automatic scrolling
lcd.noAutoscroll();
// clear screen for the next loop:
lcd.clear();
}// include the library code:
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
int thisChar = 'a';
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// turn on the cursor:
lcd.cursor();
}
void loop() {
// reverse directions at 'm':
if (thisChar == 'm') {
// go right for the next letter
lcd.rightToLeft();
}
// reverse again at 's':
if (thisChar == 's') {
// go left for the next letter
lcd.leftToRight();
}
// reset at 'z':
if (thisChar > 'z') {
// go to (0,0):
lcd.home();
// start again at 0
thisChar = 'a';
}
// print the character
lcd.write(thisChar);
// wait a second:
delay(1000);
// increment the letter:
thisChar++;
}// include the library code:
#include <LiquidCrystal.h>
const int rs = 12, en = 11, d4 = 5, d5 = 4, d6 = 3, d7 = 2;
LiquidCrystal lcd(rs, en, d4, d5, d6, d7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// initialize the serial communications:
Serial.begin(9600);
}
void loop() {
// when characters arrive over the serial port...
if (Serial.available()) {
// wait a bit for the entire message to arrive
delay(100);
// clear the screen
lcd.clear();
// read all the available characters
while (Serial.available() > 0) {
// display each character to the LCD
lcd.write(Serial.read());
}
}
}
