MQTT/IoT (general) questions...

i have played esp8266 modules before..

* captive portals (mostly used gui's control/interact connect project
* reach out , dump data custom php script (hosted on own domain/server)..

but have never used of these iot 'services' honest.

i keep seeing 'buzz word' mqtt.. etc..etc.. yadda yadda..

but i'm having troubling grasping things it.. , hoping conversation clears things me.


i understand mqtt publish/subscribe messaging protocol...

but connected/polling type of connection?  using bandwidth, needing connected able 'get' response/pushed data..... correct?

what difference between , having script on internet , request every often?

* read mqtt protocol designed lightweight...  todays bandwidth/connections issue more?  (maybe multiples or professional grade stuff?)

** read has more offerings lwt (last , testament) messages?  seems bit more robust simple script gets polled every often.


lastly..   is possible set-up/install own mqtt server?

i see things mosquito , mqtt-server...  have read them yet.

maybe possible install ona home computer/server gets opened internet via router access or something?   but shared domain hosting?  (and thoughts/feedback on that?)

i saw articles installing on rasppi???  (that fun first rasppi project me imo!)


thanks!

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i keep seeing 'buzz word' mqtt.. etc..etc.. yadda yadda..

it's not buzzword, pretty awesome.

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but connected/polling type of connection?  using bandwidth, needing connected able 'get' response/pushed data..... correct?

as far know, try keep tcp connection open, yes. traffic little, though.

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what difference between , having script on internet , request every often?

- don't have go through lengthy http dialog.
- entities try keep connected, don't have authenticate , poll time
- super fast. instant enough live-control dimmer sending increase/decrease messages to server dimmer subscribed to, without overshooting time.
- have qos (not supported mcu lib, in general, can make sure messages arrive @ least or once)
- other entities can subscribe without having change server
- have lwt, message posted when server loses connection (and timeouts reconnects) node.

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* read mqtt protocol designed lightweight...  todays bandwidth/connections issue more?  (maybe multiples or professional grade stuff?)

depends. mqtt can push it's message through 16kbit/s throttled mobile connection. wouldn't want http. also, mcu has less compared polling via http, authenticating, parsing ...

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lastly..   is possible set-up/install own mqtt server?

sure. mosquitto easy setup server. in debian/ubuntu repositories.

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maybe possible install ona home computer/server gets opened internet via router access or something? 

sure, dynamic dns friend.

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but shared domain hosting?  (and thoughts/feedback on that?)

no, not php script, actual compiled software. need root access @ least vserver.

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i saw articles installing on rasppi???  (that fun first rasppi project me imo!)

sure, no problem.
sudo apt-get install mosquitto(-server?)

anyway mqtt best thing since sliced bread. use for
- home automation communication, including switches, sensors ... openhab 1 end , wemos d1 minis (esp8266) of others
- mobile location tracing owntracks

recently, build mqtt ir converter. reads ir , dumps info (protocol, bits, address, code) mqtt topics, , subscribes other topics , sends received info ir. great have unified place can dump communication wireless units in ordered way.

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