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#!/usr/bin/python
# Python WebSocket Server for Raspberry Pi / PiFace
# by David Art [aka] adcomp <david.madbox@gmail.com>
import tornado.httpserver
import tornado.websocket
import tornado.ioloop
import tornado.web
import datetime
import json
import sys
import os
# PiFace module & init
import pifacedigitalio as pfio
pfio.init()
pifacedigital = pfio.PiFaceDigital()
class IndexHandler(tornado.web.RequestHandler):
@tornado.web.asynchronous
def get(self):
self.render("index.html")
class WebSocketHandler(tornado.websocket.WebSocketHandler):
clients = []
last_data = None
def open(self):
self.connected = True
print("new connection")
self.clients.append(self)
self.timeout_loop()
# """ Tornado 4.0 introduced an, on by default, same origin check.
# This checks that the origin header set by the browser is the same as the host header """
def check_origin(self, origin):
return True
def on_message(self, message):
# message is the PIN number you want to toggle
pin = int(message)
# read output state
r_output = '{0:08b}'.format(pifacedigital.output_port.value)
# toggle output
pin_state = int(r_output[7-pin]);
pfio.digital_write(pin, not pin_state)
# FIXME! I need to check with the loop so I don't send twice ?
self.timeout_loop()
def on_close(self):
self.connected = False
print("connection closed")
self.clients.remove(self)
def timeout_loop(self):
# read PiFace input/output state
r_input = '{0:08b}'.format(pifacedigital.input_port.value)
r_output = '{0:08b}'.format(pifacedigital.output_port.value)
# obj -> javascript
data = {"in": [], "out": []}
for i in range(8):
data['in'].append(r_input[7-i])
data['out'].append(r_output[7-i])
# only send message if input/output changed
if data != self.last_data:
for client in self.clients:
client.write_message(json.dumps(data))
self.last_data = data
# here come the magic part .. loop
# FIXME! this is going pretty bad if too many clients I think ..
# no other way to do this ?
if self.connected:
tornado.ioloop.IOLoop.instance().add_timeout(datetime.timedelta(seconds=.5), self.timeout_loop)
application = tornado.web.Application([
(r'/', IndexHandler),
(r'/piface', WebSocketHandler)
])
if __name__ == "__main__":
http_server = tornado.httpserver.HTTPServer(application)
http_server.listen(8888)
print("Raspberry Pi - PiFace")
print("WebSocket Server start ..")
try:
tornado.ioloop.IOLoop.instance().start()
except KeyboardInterrupt:
print('\nExit ..')
sys.exit(0)