Websocket Server

This example will instantiate a web server running on port 8888 with support for WebSockets enabled. The example HTML file will open a websocket and send data back and forth to Serial Port of PremierWave XN.

Prerequisites

1) Requires PySerial module - already included with the Python supported firmware
2) Download Tornado (http://tornadoweb.org) and do a manual installation.
3) Extract the "tornado" directory from the tarball (tar.gz) and upload it via FTP to the PremierWave User Filesystem partition.

Sample Code

Upload file websocket_server.py (code shown in-line) via FTP to the PremierWave User Filesystem partition.

<nowiki>

import tornado.ioloop import tornado.web import tornado.websocket import serial import time import threading

class MainHandler(tornado.web.RequestHandler): def get(self): self.render("websocketexample.html")

class WSHandler(tornado.websocket.WebSocketHandler): connections = []

def open(self): print "WebSocket opened" self.connections.append(self)

def on_message(self, message): for conn in SerialPort.ports: conn.writer(message)

def on_close(self): print "WebSocket closed" self.connections.remove(self)

class SerialPort(): ports = []

def __init__(self, serial_instance): self.serial = serial_instance self.ports.append(self)

def start(self): self.thread_read = threading.Thread(target=self.reader) self.thread_read.start()

def reader(self): while True: buffer = buffer = ser.read(ser.inWaiting()) if buffer: for conn in WSHandler.connections: conn.write_message(buffer) time.sleep(0.5)

def writer(self, data): self.serial.write(str(data))

application = tornado.web.Application([ (r"/", MainHandler), (r"/websocket",WSHandler), ])

if __name__ == "__main__": ser = serial.Serial('/dev/ttyS1') ser.timeout = 0 s = SerialPort(ser) s.start() application.listen(8888) tornado.ioloop.IOLoop.instance().start()<nowiki>