Serial.readString()

Description

Serial.readString() reads characters from the serial buffer into a String. The function terminates if it times out (see setTimeout()).

Serial.readString() inherits from the Stream utility class.

Syntax

Serial.readString()

Parameters

Serial: serial port object. See the list of available serial ports for each board on the Serial main page.

Returns

A String read from the serial buffer

Example Code

Demonstrate Serial.readString()

void setup() {
  Serial.begin(9600);
}

void loop() {
  Serial.println("Enter data:");
  while (Serial.available() == 0) {}     //wait for data available
  String teststr = Serial.readString();  //read until timeout
  teststr.trim();                        // remove any \r \n whitespace at the end of the String
  if (teststr == "red") {
    Serial.println("A primary color");
  } else {
    Serial.println("Something else");
  }
}

Notes and Warnings

The function does not terminate early if the data contains end of line characters. The returned String may contain carriage return and/or line feed characters if they were received.