Returns the next byte (character) of incoming serial data without removing it from the internal serial buffer. That is, successive calls to
peek() will return the same character, as will the next call to
Serial.peek() inherits from the Stream utility class.
Serial: serial port object. See the list of available serial ports for each board on the Serial main page.
The first byte of incoming serial data available (or -1 if no data is available). Data type: