#MQTT with local broker

1 messages · Page 1 of 1 (latest)

merry grove
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@chrome axle One wrinkle I ran into is that mosquitto requires nonlocal clients to authenticate.

chrome axle
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I don't exactly know what you mean?

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Hopefully tonight I have some time to start throwing some code in and seeing it work

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Im not exactly using a local broker i dont think? The broker would be on the PI and the client would be the esp32?

merry grove
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(In most of the Adafruit examples, they're using the MQTT broker at AdafruitIO, so it would be those credentials there.)

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Anyway, I had to do some mosquitto configuration and set up a password file. I'll try to reconstruct what I did and post some details and links sometime today.

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oh, by "local broker" I mean local to your place, under your control, vs. AdafruitIO or some other commercial broker. So yeah, on the Pi.

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(Picked up that usage from one of the Adafruit guides.)

chrome axle
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Okay. Sorry for my ignorance im so new to this stuff

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ive been python programming for about a year. But always just gui / mysql type stuff. So this is quite new and exciting

merry grove
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I know, it's great.

chrome axle
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I definitely dont want to use the adafruit broker. I want this to all run without internet connection

merry grove
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I've been programming with Python on and off since version 0.9, back in the 90s, and I still love using it.

chrome axle
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this might be a silly question, But does my router just assign an IP to the esp32 when it connects using DHCP?

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oh awesome

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im an automation programmer for a living, robots, plcs, camera systems, hmis, servos

merry grove
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Yeah, the default is DHCP, which stands for Dynamic something.

chrome axle
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ive really starting joining the two worlds of PLC and Pthon to create databases off of our machines. Before this took very expensive software

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since its publishing to a MQTT server with a specific topic the PI really doesnt care about the IP address because the topic is the unique identifier correct?

merry grove
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My career was mostly server-side programming, mostly in C and then Java when that came out. So this hardware thing is relatively new to me too, but I've been playing with microcontrollers for a few years now.

chrome axle
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Awesome

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I think this project specifically is going to really give me alot more knowledge about it

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I am currently running a furnace in my garage off of a raspberry pi

merry grove
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Cool

chrome axle
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but right now the temp sensor and furance are both wired into the PI

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this will give me total wireless freedom.

merry grove
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(I mean, warm 🙂 )

chrome axle
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My garage is quite long. So I am going to add 3 wireless temp setups then average them

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Its also very expnesive to heat because of poor insulation and it runs on propane. So I am going to add an ambient outside temp. So when I go in the garage its set to 65f. But when I leave the garage it will keep it at a minimum of 32deg or 10 deg over ambient

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I also have a database logging to temp right now so I can pull all the stats. Currently im much more efficient then the old thermostat

merry grove
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Sounds like a great and useful project!

chrome axle
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Once thats all functional I am going to do my house. But to a different level. My house has rooms that are always different temps. So I am going to create a air duct register that I can open and close. So I will have individual room thems. So I can then open and close the vents depending on which rooms need the heat

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thats pretty cool. I was just going to use the same setup because I have a shed that I could put it in thats water proof but not heated.

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im mad when I left for work today i forgot to plug the esp32 into my desktop. I was going to remote in and setup the server programming lol

merry grove
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Well, your job sounds like it has its attractions as well.

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What's PLC?

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programmable logic controller?

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(That just means microcontrollers these days, right?)

chrome axle
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thats right

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and not really

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because PLCs have their own programming language

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its ladder programming. Very simple for the most part. But data handling is trickty

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everything always runs in a loop

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in automation every device I touch has different programming. Every PLC has their own version of ladder. Every Robot has their own programming syntax.

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but its all pretty simple

merry grove
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I'll stick to Python 🙂

chrome axle
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I was trying to send you a video of a machine i did recently but discord has an 8mb limit

merry grove
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I'd be interested, if you can post it elsewhere

chrome axle
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my fricken phone videos are huge 1min 30 seconds 200mb

merry grove
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The downside of hi-res

chrome axle
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yep

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and the new cameras are even more hi lol

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im just stepping out for lunch I have an ftp I can send it to

merry grove
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Thanks. I'll scrounge up the stuff about mosquitto configuration and post back here.

chrome axle
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what is this chat window? is this public?

merry grove
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It's a thread under help-with-circuitpython. You can see it listed under the icon at the top of the window that looks sorta like a pound sign followed by a digit

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Just a way of moving a discussion out of the main topic

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yeah, it's public

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The mosquitto configuration stuff is all under /etc/mosquitto, with /etc/mosquitto/mosquitto.conf being the main config file.

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You don't actually edit that though, as the comments in it explain.

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So in /etc/mosquitto/conf.d, I made a file access.conf that looks like this

# 
listener 1883
password_file /etc/mosquitto/conf.d/pwfile.txt
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(The 'listener' is because it just wants to listen to the ssl port -- 6883?

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In the password file, I started out with
tester:testing
then (inadvertently?) did something to encrypt the passwords; prolly wasn't necessary

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man mosquitto_passwd describes managing the password file

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user/pass goes in the corresponding parameters to the MQTT.MQTT call on the S2.

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Clients running on the host a slightly different interface; client creation and connection is like:

import paho.mqtt.client as mqtt
# ...
client = mqtt.Client('testing')
client.on_connect = on_connect
client.on_subscribe = on_subscribe
client.on_message = on_message

client.username_pw_set('tester', 'testing')
msginfo = client.connect("127.0.0.1", 1883, 60)
chrome axle
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thanks for the info

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i sent you a PM with the link for the machines

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how do I get the paho lib onto the microcontroller?

merry grove
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The paho lib is for the PI; you're using adafruit_minimqtt on the mcu

chrome axle
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oh okay

merry grove
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The minimqtt lib is described as modelled on the paho one, but obviously different in setup to account for not being able to assume a network connection is there for the taking

chrome axle
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how would you suggest starting on the project. I have a MQTT server going. So should i start with the microcontroller trying to push data? Is there a way to see that the server is receiving it? or do I need both ends working

merry grove
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That's why I have a 'read everything' client running on the Pi. I'll post the code after a bit -- need to do something here for a while.

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So yeah, I think you need to get the authentication stuff working, and you need a subscribing client to see what's being published.

chrome axle
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no problem. I am just hoping I have time tonight to work on it lol

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im in process of building a new race car lol

merry grove
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(Slightly cleaned up for sharing; I don't think I broke it in the process)

chrome axle
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thanks for the program

merry grove
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In the on_message function, you'll see that the message is bytes or a bytearray; by default in minimqtt, messages are strings instead.