ESP8266 Community Forum

Can anyone supply me with the specs of MQTT (especially the packet layouts etc.)?

Also I wonder what most people use as the receiving end. Formally this would be a "broker" that would forward the message to another client(s). But I assume it's mostly used to send and store sensor values, so the receiving end would not be brokering but storing the data?

For the time being it still looks something that's not that difficult to implement.

I found this guide to be pretty useful.

http://www.steves-internet-guide.com/mq ... %20message,)%20%2B%20Variable%20Header%20%2DExample%20PUBACK

also

https://mqtt.org/mqtt-specification/

Very interesting read and also clear.

For the moment I have two questions though:

- the format of the message is not dictated by the standard, so it can be anything we like. This imposes the question, what format is used commonly for sending sensor readings to a "broker"?
- I think most sensor readings are not worth spending much reliability measures on, especially on a contrained microcontroller and also TCP is used (I would expect UDP, actually). So I consider discarding each message as soon as it's sent and not wait for the confirmation, which would hog precious resources.