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.

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()