Arduino Serial Print Example

Simple updated examples of arduino serial communications

Say I have some variables that I want to print out to the terminal, what's the easiest way to print them in a string? Currently I do something like this: Serial.print('Var 1:');Serial.println(var.

arduino_multibyte_serial_example_1.pde

/* ------------------------------------------------

* SERIAL COM - HANDELING MULTIPLE BYTES inside ARDUINO - 01_simple version

* by beltran berrocal

* this prog establishes a connection with the pc and waits for it to send him

* a long string of characters like 'hello Arduino!'.

* Then Arduino informs the pc that it heard the whole sentence

* this is the first step for establishing sentence long conversations between arduino and the pc.

* serialRead() reads one byte at a time from the serial buffer.

* so in order to print out the whole sentence at once

* (it is actually still printing one byte at a time but the pc will receive it

* not interupted by newLines or other printString inside you loop)

* You must loop untill there are bytes in the serial buffer and

* and print right away that byte you just read.

* after that the loop can continue it's tasks.

* created 15 Decembre 2005;

* copyleft 2005 Progetto25zero1 <http://www.progetto25zero1.com>

* --------------------------------------------------- */

int serIn; //var that will hold the bytes in read from the serialBuffer

voidsetup() {

Serial.begin(9600);

}

//auto go_to_the_line function

//void printNewLine() {

// Serial.print(13, BYTE);

// Serial.print(10, BYTE);

//}

voidloop () {

//simple feedback from Arduino Serial.println('Hello World');

// only if there are bytes in the serial buffer execute the following code

if(Serial.available()) {

//inform that Arduino heard you saying something

Serial.print('Arduino heard you say: ');

//keep reading and printing from serial untill there are bytes in the serial buffer

while (Serial.available()>0){

serIn =Serial.read(); //read Serial

Serial.print(serIn, BYTE); //prints the character just read

}

//the serial buffer is over just go to the line (or pass your favorite stop char)

Serial.println();

}

//slows down the visualization in the terminal

delay(1000);

}

arduino_multibyte_serial_example_2.pde

/* ------------------------------------------------

* SERIAL COM - HANDELING MULTIPLE BYTES inside ARDUINO - 01_simple version

* by beltran berrocal

* this prog establishes a connection with the pc and waits for it to send him

* a long string of characters like 'hello Arduino!'.

* Then Arduino informs the pc that it heard the whole sentence

* this is the first step for establishing sentence long conversations between arduino and the pc.

* serialRead() reads one byte at a time from the serial buffer.

* so in order to print out the whole sentence at once

* (it is actually still printing one byte at a time but the pc will receive it

* not interupted by newLines or other printString inside you loop)

* You must loop untill there are bytes in the serial buffer and

* and print right away that byte you just read.

* after that the loop can continue it's tasks.

* created 15 Decembre 2005;

* copyleft 2005 Progetto25zero1 <http://www.progetto25zero1.com>

* --------------------------------------------------- */

int serIn; //var that will hold the bytes in read from the serialBuffer

voidsetup() {

Serial.begin(9600);

}

//auto go_to_the_line function

//void printNewLine() {

// Serial.print(13, BYTE);

// Serial.print(10, BYTE);

//}

voidloop () {

//simple feedback from Arduino Serial.println('Hello World');

// only if there are bytes in the serial buffer execute the following code

if(Serial.available()) {

//inform that Arduino heard you saying something

Serial.print('Arduino heard you say: ');

//keep reading and printing from serial untill there are bytes in the serial buffer

while (Serial.available()>0){

serIn =Serial.read(); //read Serial

Serial.print(serIn, BYTE); //prints the character just read

}

//the serial buffer is over just go to the line (or pass your favorite stop char)

Serial.println();

}

//slows down the visualization in the terminal

delay(1000);

}

arduino_multibyte_serial_example_3.cpp

/* ------------------------------------------------

* SERIAL COM - HANDELING MULTIPLE BYTES inside ARDUINO - 03_function development

* by beltran berrocal

* this prog establishes a connection with the pc and waits for it to send him

* a long string of characters like 'hello Arduino!'.

* Then Arduino informs the pc that it heard the whole sentence

* the same as examlpe 02 but it deploys 2 reusable functions.

* for doing the same job.

* readSerialString() and printSerialString()

* the only problem is that they use global variables instead of getting them passed

* as parameters. this means that in order to reuse this code you should also copy

* the 4 variables instantiated at the beginning of the code.

* Another problem is that if you expect more than one string at a time

* you will have to duplicate and change names to all variables as well as the functions.

* Next version should have the possibility to pass the array as a parameter to the function.

* created 15 Decembre 2005;

* copyleft 2005 Progetto25zero1 <http://www.progetto25zero1.com>

* --------------------------------------------------- */

int serIn; // var that will hold the bytes-in read from the serialBuffer

char serInString[100]; // array that will hold the different bytes 100=100characters;

// -> you must state how long the array will be else it won't work.

int serInIndx = 0; // index of serInString[] in which to insert the next incoming byte

int serOutIndx = 0; // index of the outgoing serInString[] array;

/*read a string from the serial and store it in an array

//you must supply the array variable and the index count

void readSerialString (char *strArray, int indx) {

int sb; //declare local serial byte before anything else

Serial.print('reading Serial String: ');

if(serialAvailable()) {

while (serialAvailable()){

sb = serialRead();

strArray[indx] = sb;

indx++;

serialWrite(sb);

}

Serial.println();

}

//read a string from the serial and store it in an array

//this func uses globally set variable so it's not so reusable

//I need to find the right syntax to be able to pass to the function 2 parameters:

// the stringArray and (eventually) the index count

voidreadSerialString () {

int sb;

if(Serial.available()) {

//Serial.print('reading Serial String: '); //optional confirmation

while (Serial.available()){

sb = Serial.read();

serInString[serInIndx] = sb;

serInIndx++;

//serialWrite(sb); //optional confirmation

}

//Serial.println();

}

//print the string all in one time

//this func as well uses global variables

voidprintSerialString() {

if( serInIndx > 0) {

Serial.print('Arduino memorized that you said: ');

//loop through all bytes in the array and print them out

for(serOutIndx=0; serOutIndx < serInIndx; serOutIndx++) {

Serial.print( serInString[serOutIndx] ); //print out the byte at the specified index

//serInString[serOutIndx] = '; //optional: flush out the content

}

//reset all the functions to be able to fill the string back with content

serOutIndx = 0;

serInIndx = 0;

Serial.println();

}

voidsetup() {

Serial.begin(9600);

Serial.println('Hello World');

}

voidloop () {

//simple feedback from Arduino

//read the serial port and create a string out of what you read

//readSerialString(serInString, serInIndx);

readSerialString();

//do somenthing else perhaps wait for other data or read another Serial string

Serial.println ('------------ arduino is doing somenthing else ');

//try to print out collected information. it will do it only if there actually is some info.

printSerialString();

//slows down the visualization in the terminal

delay(2000);

}

commented May 3, 2013

nice write up man.

Arduino Serial Print Example Template

commented Aug 22, 2015

The 'BYTE' keyword is no longer supported!

commented Jun 7, 2018

What if we wand to send integers like 465 through uart Definitely We have to send 4,6,5 but how to what functiion is over here which can hepl us. Or we have to create our own function. Please answer .