Arduino Reference - Write

write()

Description

Writes binary data to the serial port. This data is sent as a byte or series of bytes; to send the characters representing the digits of a number use the print() function instead.

Syntax

Serial.write(val)
Serial.write(str)
Serial.write(buf, len)

Arduino Mega also supports: Serial1, Serial2, Serial3 (in place of Serial)

Parameters

val: a value to send as a single byte

str: a string to send as a series of bytes

buf: an array to send as a series of bytes

len: the length of the buffer

Returns

byte
write() will return the number of bytes written, though reading that number is optional

Example

void setup ( ) {
Serial.begin ( 9600 ) ;
} void loop ( ) {
Serial.write ( 45 ) ; // send a byte with the value 45 int bytesSent = Serial.write (“hello”) ; //send the string “hello” and return the length of the string.
}