CODEWITHSUNDEEP
javascriptpythonwebsocketserial-porttornado
Jake Jake
Jake Jake

Reputation: 33

Server side serial over python tornado chat

I am looking for a way to modify the Tornado Websockets Chat Demo in order to communicate with a serial port on the server over the chat. Shown below is the method(?) called on when a message is sent. I can write to serial fine sending the body of the message to the serial.write(). But the problem is I am only able to get the serial feedback once. However in my current application the serial may send in data more than just when spoken to. 

    ...
    import serial
    serial = serial.Serial("COM3", 57600)
    ...
    def on_message(self, message):
        test = ""
        logging.info("got message %r", message)
        parsed = tornado.escape.json_decode(message)

        serial.write(parsed["body"] + "\n")
        logging.info("SENT " + parsed["body"] + "\n")
        test = serial.readline()

        chat = {
            "id": str(uuid.uuid4()),
            "body": test,
            }

        chat["html"] = self.render_string("message.html", message=chat)

        ChatSocketHandler.update_cache(chat)
        ChatSocketHandler.send_updates(chat)

Is there a way to constantly poll the serial and handle the websockets IO at the same time? Also if there is an easier alternative to Tornado with realtime multiple page updates I would not be opposed. Although I do like Tornado.

Upvotes: 3

Views: 1353

Answers (2)

niltoid
niltoid

Reputation: 839

I've used a different approach using Tornado and Python's multiprocessing library. Details are available here:

Raspberry Pi + Tornado + Arduino

Upvotes: 1

oberstet
oberstet

Reputation: 22051

Since you are open for other approaches, you might be interested in this complete working example, demonstrating real-time charts in browser instances driven from an Arduino sensor board via serial and WebSocket. This uses Autobahn and Twisted.

Disclosure: I'm original author of Autobahn and work for Tavendo.

Upvotes: 1

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