Arduino Serial Print and Println Function to Send Integer Variable And Text Program Code

Arduino Serial print Function Application

Serial.write() function send the data in ASCII code. It means if you want to send the value of a integer variable with the help of write function you have to convert value into ASCII format.

For example if suppose a variable x having value 87 x = 87; and we want to send 87 in the serial monitor. We have to send two character ASCII of 8 ( 0x38 ) and ASCII of 7 ( 0x37 ).

Serial Print vs println Function Difference

The Serial.write(x); function send x as ASCII and Serial.print(x) convert the x into digits and then send the ASCII of those digits.

How to Use Arduino Serial print Function to Send Integer Variable

It is very difficult to send value of integer variable with the help of Serial.write() function, the example below shows use of print function for the same task.

/*
	Arduino serial print vs write difference test code example
	https://elextutorial.com
*/
void setup() 
{
  Serial.begin(9600);// Set the baud rate to 9600
}
void loop() 
{
  int x = 87;
  Serial.write(x); // write in the int type variable.
  Serial.write("\n"); // send new line.
  Serial.print(x); // print in the int type variable.
  Serial.write("\n"); // send new line.
  delay(1000); // Wait for 1 second for next read.
}
				 

Fig.1 shows characters received in monitor program “W” and times 87, because 87 is decimal equivalent of “W”.

How to Use Arduino Serial print Function to Send String Variable or Text

The print function can also be used to send string or text variable over serial port. The below example shows the code for the same.

/*
	Arduino serial print test code example to send string
	https://elextutorial.com
*/
void setup() 
{
  Serial.begin(9600);// Set the baud rate to 9600
}
void loop() 
{
  String s1 = "Welcome Back to https://elextutorial.com";
  Serial.print(s1); // print the string type variable.
  Serial.write("\n"); // send new line.
  delay(1000); // Wait for 1 second for next read.
}
				 

Fig.2 shows string received in serial monitor.

Arduino Serial println Function

The Arduino Serial println function does the same thing as compared to print, additionally println also send new line ( \n ) character in the end.

It means after sending integer or string println send one more thing, that is new line. In serial monitor the new line character is not visible, but the next received information is display on a fresh line.

The below example is used to show the decimal ASCII code of alphabet from ‘a’ to ‘z’.

/*
	Arduino serial println test code example to send ASCII decimal code of character a to z.
	https://elextutorial.com
*/
void setup() 
{
	Serial.begin(9600);// Set the baud rate to 9600
}
void loop() 
{
	int x;
	for(x = 'a'; x<='z'; x++)
	{
		Serial.write(x); // send x as character.
		Serial.print(" decimal ASCII Code is => "); // print the string as it is for information.
		Serial.println(x); // print the int variable with new line.
		delay(1000); // Wait for 1 second for next read.
	}
	while(1);// Halt the program in infinite loop.
}
				 

The figure above shows the display of decimal value of character in the serial monitor.