readBytes() read characters from a stream into a buffer. The function terminates if the determined length has been read, or it times out (see setTimeout()).

readBytes() returns the number of bytes placed in the buffer. A 0 means no valid data was found.

This function is part of the Stream class, and can be called by any class that inherits from it (Wire, Serial, etc). See the Stream class main page for more information.


stream.readBytes(buffer, length)


  • stream : an instance of a class that inherits from Stream.
  • buffer : the buffer to store the bytes in (char[] or byte[])
  • length : the number of bytes to read(int)


  • The number of bytes placed in the buffer (size_t)
Please note: These are affiliate links. If you buy the components through these links, We may get a commission at no extra cost to you. We appreciate it.