Serial

write()

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);
// EXAMPLE USAGE

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.
}

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

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