Flask-SocketIO VS mqtt-web-test

The framework is driven by the AsyncAPI specification, built on top of Flask-SocketIO. and inspired by Connexion.

I don't know what module you're using for websockets, but looking at an issue posted on one of them, the thread should periodically sleep in order for I/O to function properly.

I'm running a Flask server on my local machine and am using it to pull data from a serial port and display it in real time on a webpage with Flask-socketio. I followed the example here and am encountering an interesting behavior. I was able to replicate the results of the example, but when I alter the background_thread function to include reading and parsing data from the serial port, something seems to be blocking the socket from sending the data. My code correctly establishes a socket and opens the connection, and can even emit messages correctly at the beginning of the thread function, but once it hits a time.sleep(5), emitting doesn't work anymore. Here's the original thread function that works (and includes a time.sleep()!):

https://github.com/miguelgrinberg/Flask-SocketIO/issues/1010 looks like flask socket io does not support waitress

I have Flask application with SocketIO integration.Current user flow seems like 

I think you're having this issue. https://github.com/miguelgrinberg/Flask-SocketIO/issues/1570

Check Miguel's flask-socketio examples.

In terms of streaming anything to a client, I would suggest websocket functionality. There's a Flask-SocketIO package that can be used on the server side, and then on the client side you could use the built-in Javascript websocket functionality, or the Socket.IO library. That would allow you to push messages/data in both directions as needed... the server could just push data to the client whenever there's data to be pushed, and the client could handle that as needed.

GitHub Flask-SocketIO

An update to my question (i'd solved the text display), repo for reference. So now I wanted to store received data into csv. Reason is i will display in a graph/chart later. For some reason it doesn't work where I don't see the data being updated in csv. I used the example from here and here (base code is in here). With those example, my code is:

I gonna post the repo here so you can check what's faulty there. I use DHT11_MQTT_Pub.ino to pub/sub with esp (although i can use mqtt_pub_test.py as dummy). Flask server is in mqtt-mosquitto-pi.py.