WebSocket (WebSocket.h)

WebSocket Server for Arduino This library implements a Websocket server running on an Arduino. It's based on the proposed standard published December 2011 which is supported in the current versions (June 2012) of Firefox, Chrome, and Safari 6.0 beta (not older Safari, unfortunately) and thus is quite usable. The implementation in this library has restrictions as the Arduino platform resources are very limited: The server only handles TXT frames. The server only handles single byte chars. The Arduino just can't handle UTF-8 to it's full. The server only accepts final frames with maximum payload length of 64 bytes. No fragmented data, in other words. For now, the server silently ignores all frames except TXT and CLOSE. The server only handles one client at a time. Trying to connect two at the same time will force the old client to disconnect. There's no keep-alive logic implemented. Required headers (example): GET /whatever HTTP/1.1 Host: server.example.com Upgrade: websocket Connection: Upgrade Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ== Origin: http://example.com Sec-WebSocket-Version: 13 The server checks that all of these headers are present, but only cares that the version is 13. Response example: HTTP/1.1 101 Switching Protocols Upgrade: websocket Connection: Upgrade Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo= The last line is the Base64 encoded SHA-1 hash of the key with a concatenated GUID, as specified by the standard. Requirements Arduino IDE 1.0.1 or greater. You should not use 1.0 since it has a bug in the Ethernet library that will affect this library. An Arduino Duemilanove or greater with Ethernet shield. An Arduino Ethernet should work too, but it has not been tested. A Websocket client that conforms to version 13 of the protocol. Getting started Install the library to "libraries" folder in your Arduino sketchbook folder. For example, on a mac that's ~/Documents/Arduino/libraries. Try the supplied echo example together with the the web based test client to ensure that things work.