Beginner Gets Sucess

[chehre]

Hi, Thank you for very well explained threads of steps in making this home automation project.

I am having questions regarding different steps and aspects of the project.
I have tried the method presented in the instructables of uber sensor home automation and could not accomplish what they had done in 2014.
Well libraries have been updated, mainly rfm69 library and also openHAB 3 is now out there to start with.
I couldn't see any posts from 2021 in this forum and was wondering if somebody could help me out there so I explain the speed bumps more in details.

[papa]

Greetings chehre,

You are correct that contributions to this board have been small. A hundred or so visitors stop by each day, but I hear little from them. I have posted some tweaks even in 2021, but my efforts here have mainly been nuking spam. My openHAB system as described in this board still works very well. However I have been busy with other things & few visitors have contributed new projects, asked questions, or even say "thank you" (I appreciate that you did). With my having limited time, it's hard to be motivated to take things further.

I may have a little more time opening soon. Give me some more information, & we'll see what we can do: To start with, what is your experience with building electronics & programming them? Also did you follow my advice & start with ESP8266 (wifi) devices that don't need the RFM69 library or the RFM69 Gateway (which is challenging)?

[chehre]

Thank you again for considering to help me, and I must say that I'm really happy and hopeful about finding this forum.
To answer your question about my experience with electronics; I am not a professional but have done some works with Arduino, such as simple network using NRF24L01 modules but only for very simple hardware, like turning on and off lights on another node (not with sensors yet). I have made MIT application to control simple things via mobile phone via bluetooth module HC-05 (I guess). And of course other things such as clocks and radio (following tutorials online).
In total I am not very experienced with writing the codes but I had always been able to make things work until RFM69 project which is really complicated.

And about your question regarding to start with ESP8266, I actually did not do that but I'll give it a try right now. The reason for this is that as I have researched online, those ESP8266 modules are power consuming and are only efficient for short ranges but I'll go to see your tutorial right after writing this post, as I already have some ESP8266 NodeMCu boards around.
Another reason for jumping to RFM69 is that I have the software available: RFM69HCW modules, Arduino Uno compatible boards (with 5-3.3V slide switch for operation power of the board), So many sensors that I want to use, Ethernet shield (VCC pin of ICSP cut off), Raspberry Pi with MQTT broker and Openhabian installed, OpenHAB 3 account made (but by following the Instructables post's instructions) and actually everything else needed for the hardware part of the project.

My questions for now are as follows:
1. The Gateway sketch (RFM_MQTT_GW_25.4_pub.ino), which versions of the libraries RFM69 and Pubsubclient are used? Can I use the latest versions? Do I have to make changes in the libraries and if yes, would you guide me with the path please?
2.How can I start everything from scratch to openHAB 3? I have seen you made posts about backup from openHAB 2 to openHAB 2.5, but I cannot find the way to start on openHAB 2 so I could follow backup instructions given by you and the openHAB documents.
3. To follow your end nodes I had the confusion of where to start first and which gateway version do they follow.

Now I'll be going to see how ESP8266 home automation turns out. Faithfully waiting for your kind response.

[chehre]

Hi
As the tutorials for ESP8266 was not any DIY sensor nodes, I couldn't follow them, I'll look around on the net to see what I can find. But still having the RFM69 project in the side of my mind to jump to it as soon as road gets a little bright.

[papa]

chehre, I cannot answer much at the moment, but I'll offer one caution: You wrote, "following the Instructables post's instructions"

If by Instructables, you mean the UBER Home Automation original version of the project, that Instructable was very inspiring. However, be warned that the RFM69 Gateway in this forum is a different improved version of the Instructable's RFM69 Gateway.

I'll try to respond to your other postings when I get more time.

[chehre]

Yes, I know that the instructions given in this forum is aiming for only one Gateway (Arduino compatible board + RFM69 Module + Ethernet shield connected to the modem) while Eric Tsai had done it with 2 gateways. I like your way better, plus it frees one of my boards and one less battery or charging cable and less power consumption probably.

I'm more confused about libraries versions and that which versions did you use and I'm trying to figure out configuration with OpenHAB 3.

Please take your time.

[papa]

As I documented in this thread, I'm at openHAB 2.5.10 & don't remember any more issues affecting my setup than I faced with OH 2.5.0. However, for now I suggest you set aside openHAB.

Let's focus first on getting a mostly working Gateway as documented in this thread. By mostly working I mean you've succeed in completing the thread through the end of this post so that 1) the RFM69 radio initialized & 2) the RFM69 Gateway has an IP address from your router, (but no MQTT connection yet because that comes with the openHAB install).

             We'll try to take it  s l o w on this complex project ...   To check some basic requirements ...

                 For your Gateway, what specific Arduino do you use?       How do you power the Arduino?

     What specific Ethernet Shield do you have?               What RFM69 radios are you using?

(The RFM69 radio is damaged by 5 volts & needs a high level of current at 3.3 volts)

You ask what Library versions I've used so far. We'll get to that, but first answer the above questions about Gateway components.

[chehre]

Hi

Sorry to reply this late, I was out of the city.



Okay let's start from scratch.

1. I'm using Seeeduino V4.2 boards as they have 3.3v operational voltage switch on them.
2. For the these first initializations and setting up of first node and the gateway I am using two USB cables connected to two ports of my laptop. 
    I have also tried it with batteries connected to the system.
    9V battery through DC jack - or - 4x AA 1.5V batteries connected to the Arduino Vin and GND pins

3. A Ethernet shield board with Wiznet W5100 chip on board, and as your instructions I took off its VCC port (ICSP section of the board) so that the VCC pin of the Seeeduino won't be connected to VCC pin of the ethernet shield.
    When the ethernet shield is sitting on top of Seeeduino, the voltage readings according to my multimeter are not stable at all.
    On pin 3.3V and pin 5V of the ethernet shield I have stable 3.3v and 5v respectively but on digital pins 8-9-10-11-12-13 I have unsteady voltage ratings (below 3.2Volts, it reaches 0.3 Volts also), and this change of voltage happens so fast that I don't really think that it could cause a problem as long as not more than RFM's 3.6V limit.

4. As my RFM type, I'm having several RFM69HCW- 868 MHz modules.

[papa]

My initial responses to the information you provided ...

1. Thanks for the link to the Seeduino boards specs. There I see

    DC Output Current-3V3 Pin 500mA Max
        DC Current per I/O Pin 40mA

4. RFM69HCW: the H means longer range communication, but also needs a lot of current. I'll need to research if the Seeduino board has enough current for the RFM69 radio.

3. "unsteady voltage ratings (below 3.2Volts. it reaches 0.3 Volts also)" Unsteady power (voltage & current) can mean the RFM69 radio resets instead of staying initialized.

However, added May 29, 2021, looking again at the Seeduino's specifications, it seems like it should have enough power for the RFM69Hxx radio.
     When the Ethernet Shield is installed, it's likely that digital pins would fluctuate.

[chehre]

Thank you for considering to help me with my home automation project


There might be a problem with my USB cable!! It is a new one but just to be sure I will get another to see if anything changes.
Also I tried to measure when connected to batteries, for a second there I got a steady value on one of digital pins but it got unsteady again. I'll get a new battery by tomorrow and also will try to find a JST cable battery connector for it as it is more mature way to connect the battery to Seeeduino boards as there isn't any DC Jack, Or maybe I could get a dc jack module. I'll see what I can find. The batteries I tried, - and + are each soldered to a piece of thicker wire (I think 24AWG) which is not thick enough to fit in Arduino headers so I'm using breadboard to connect everything together which probably is not the best choice to make.  Anyways I'll check my connections and make sure about it hopefully by tomorrow.

However I listed in below the ratings when connected with USB cable to laptop.

This is the Ethernet Shield pins' reading when it is sitting on a Seeeduino board:
Between 0.7mA - 34.4 mA pin10 unsteady
Between 4.7mA - 37.1 mA pin9 unsteady
Between 3.4mA - 38.2mA pin8 unsteady
Between 4.0mA - 37.7mA pin11 unsteady
Between 4.9mA - 37.5mA pin12 unsteady
Between 7.3mA - 35.7mA pin13 unsteady
Steady 300mA pin3.3V 
Between 3.0mA - 37.2mA pin2 unsteady

This is readings for a Seeeduino pins:
Between 3.5mA - 37.1mA pin2 unsteady
Between 4.6mA - 39.0mA pin3 unsteady
Between 6.4mA - 37.2mA pin8 unsteady

For both group of readings, the Arduino board was switched to 3.3V operational voltage.

When USB cable was disconnected and 9v battery was connected by the method I described earlier, other than that 1 second stable (30 something mA), it got unstable in a limit just like the readings shared above.

[papa]

Regarding your pin readings, my knowledge is largely limited to the general info I provided earlier. One thought is that an installed Ethernet Shield should affect the power that is used & available for other things (like the RFM69 radio).

Have you also connected the RFM69 radio?

Were you able to upload new programming to the Arduino? Or is the Arduino just running the basic blink sketch?

If needed, I may have an alternate method to power your seeduinos reliably.

[chehre]

I will try uploading sketches again and will give you proper answers by tomorrow.
For the readings I posted earlier, no, RFM was not connected.
Uploading the programs to these boards is kind of a pain, every once in a while it works but other than that just errors for the boards even though the Seeeduino boards are installed from the board manager.
That's why it is a little time consuming and I said tomorrow so I can find the time for that.
But to mention All the readings are when no sketch is uploaded and only when the board is connected to laptop port via USB cable.

Thank you, I guess a reliable method for powering the boards is very important.

[papa]

Aug 21, 2021 17:49:23 GMT -5 chehre said:
Thank you, papa. Sorry that I'm replying late.

As we have talked previously in here: homeautomation.proboards.com/thread/591/beginner-stuck?page=1&scrollTo=4227

Like before, I'm trying to set up an home automation system, I have a bunch of sensors that I wanna make some general systems and some kind of unique use of them in the project.

I am using Seeeduino boards which is compatible with Arduino. RFM69HCW radio modules as the connection protocol.
You have suggested that it's better to start with ESP8266 (Wi-Fi) method as it is not that complicated, I went through the topics I could find and I remember there was a Youtube playlist that you had shared in one topic but those tutorials were based on some market sensors that I do not own, so I couldn't really follow them.
If you think that it's important that I pass those steps, I'll try to find those commercial components and get them work.

If not, I will stick with the RFM versions because although it is complicated but it has its advantages specially in range of operation and power consumption, because I want to make use of some of the sensor nodes in remote places and big areas like a farm (actually several farms).

As said in your last comment on the topic, I had to read the the voltage and amperage on my pins (Ethernet shield on top of Seeeduino) when connected with battery or through USB cable when a sketch is uploaded to the board.

I just got arrived, as I just got arrived, I'm settling in, but in about 2-3 hours I'll check them.

You also had mentioned that you might have a better reliable way for powering the boards, please give more information about that if possible.

[papa]

chehre, As I say in the DIY Automation overview thread, ESP82xx nodes are easier in the sense that they directly connect to the system via WiFi & nodes don't require a RFM69 Gateway. However, I agree, RFM69 communicates more at a distance & this forum does much more with sensors attached to RFM69 nodes.

You've been warned about the hurdle of getting a RFM69 Gateway talking with the first RFM69 node & can proceed on RFM69 with that in mind.

In the thread Building an RFM69 Home Automation Network (Beginners ??), I've tried to provide a lot of help on accomplishing that first RFM69 network.

So let's see if such posts, etc. can get your RFM69 system running.

[papa]

chehre, Looking again at the Seeduino's specifications, it seems like it should have enough power for the RFM69Hxx radio.

When the Ethernet Shield is installed, it's likely that digital pins would fluctuate in power levels.

If we determine later that power supply is a problem, I can provide you a schematic for a different power supply.

                For now, let's move on to what happens when you upload RFM69 sketches to the Seeduino.

chehre: "Uploading the programs to these boards is kind of a pain, every once in a while it works but other than that just errors for the boards even though the Seeeduino boards are installed from the board manager."

papa: Give specifics on the uploading errors you see. Have you done an internet search about the errors you see?

papa PS: Since we communicated in earlier months, my openHAB-Arduino IDE computer totally crashed & I had to start over on another computer. Some things were backed up elsewhere, some not. My openHAB (3) is mostly up, but I have not fully configured the recent Arduino IDE that I installed on another computer. The good news is that I'll probably be using versions of IDE & code library files similar to yours. So we may troubleshoot uploading errors together.

Try not to stress too much. Work at your project in a steady way & try to enjoy what your learning & accomplishing. We all start somewhere.

I'm in no hurry. I have other things that claim my attention.

[papa]

Aug 23, 2021 ... chehre said:

Thank you, papa, I understand.

Actually because of the 2-2.5 months delay in my project, I thought it would be best to go through your tutorials about setting up the Gateway and the first node, it took me longer than I thought (it is not finished yet), but I really am learning.

It is great how resourceful your threads are.

I have to head to work, I will finish my readings and write to you later.

Have a nice day.

[papa]

Thanks chehre, for your encouragement on my threads. I see statistics of people stopping by this forum, but rarely do they comment.

I believe you will benefit from working carefully through the tutorials on setting up the Gateway & first node. Yes, it does take time.

Also I'm happy to see that you are using & benefiting from my troubleshooting threads & posts on this forum.

That should help you get UNSTUCK with your DIY Home Automation project.

[chehre]

hello dear Papa,

I apologize for not being able to follow up in the past two months. I tried to continue my work whenever I got the chance but I thought it wouldn't be fair to ask questions before browsing through this forum first and I must say, it is both heart warming and confusing how so many things have been addressed in here.

And again I want to thank you and say that I appreciate your time and consideration for helping me out, please don't consider my disappearance as an act of impoliteness.



Today I spend the whole day testing out my RFM modules with the Second Method of Testing RFM69s. First I got my radios initialized with a very weak (I think) RSSI for about -60 in 10 cm distance, -90 in 1m distance and "Not ACKnowledged, no reply" in 2m distance between the two nodes, it didn't get interrupted.
I was following the exact instruction of your post.
Then I tested a bunch of other modules which I wanted to make sure if any of them is not burnt. I got no acknowledgement for any of those modules, then I switched to some other newly bought modules and they got acknowledged for like first two tries of typing "1 and 2" in the serial monitor but then not acknowledged till I got tired of trying. Btw the wires are fine and as the length instructed in your post came short for me and also as the wires which are soldered to the holes of the RFM are a bit thin so they aren't fit to the female sockets of the Seeeduino Arduino compatible board, therefore I have to use small breadboards for the connections.
Now the first two tries which didn't get interrupted earlier but had weak RSSI strength, are just showing "Not ACKnowledged, no reply" on the serial monitor.

Other than that, I now have installed Openhabian on a Raspberry Pi 4, Mosquitto is installed on Raspberry pi and on OpenHAB 3. I have read most of the documentation on the OpenHAB Docs, I just am not sure how to start configuring the First Node and also Gateway with OpenHAB.

Very appreciative if you give me another shot to be tutored.

[chehre]

Meanwhile struggling with the RFM modules, I am working on OpenHAB Configuration as it is my bigger speed bump on the way to complete a Gateway and a Node.

I followed up that thread until this post and I don't know how to access to the directories to create a file!! (I've searched on the net for root accessing, but none of those commands tend to be right), I enter the OpenHAB Console but can't do much more from there.
 
I've installed the Openhabian OS via Raspberry Pi Imager on a 16GB SD card which is inserted into a Raspberry Pi 4 connected via Ethernet to the modem. I use Putty for SSH connection to the pi, Mosquitto MQTT broker is installed on the pi by the Openhabian configuration tool ("sudo openhabian-config" command). 

On [Raspberry Pi's IP Address (Host of OpenHAB) : 8080] , I have installed MQTT binding and some other things but I wonder how I can access directories to be able to create files, add some text on an existing files etc.

It should be doable on SSH connection, I just don't know how. I wonder if installing OH OS on Raspi was the best choice.

[papa]

greetings, chehre, I've seen that you stop by the forum regularly. I appreciate that you've tried to use the instructions here before asking for help.

My problem is that shortly today, I will be unavailable for about a week & then will need to catch up a bit after that.

I'm not sure what to say about your RFM69 difficulties. I'll need to think & (when I get opportunity) ask more questions.

Meanwhile, your practicing with openHAB seems like a good idea. I'm rusty on using SSH.

Sorry, I must leave. I suggest you do an internet search on something like "SSH into openHAB files"

            Couple of quick thoughts:

    1) Can you attach a keyboard & a monitor to the Pi & just use Linux commands in the Pi's Terminal

           BTW you can edit protected Linux files by executing sudo leafpad in Terminal (or sudo [text editor name].  (you need to know the Pi's Linux password)

                 navigate leafpad to the files folder.

2) I vaguely remember that after you ssh into the Pi, that you basically have a Linux Terminal window to execute commands (like sudo leafpad)

[chehre]

Very glad to see your response. Thank you for the suggestions, I'll look into them and try to find my way. I aim to get the project to work on different / supplemental approaches like RFM and WiFi and Ethernet nodes in this week. I'll make a good report and post it here for next week when you come back.
Have a nice week.

[papa]

Thanks for understanding.

Though they are old, couple things on Pi openhab & editing it's files may give you hints:

homeautomation.proboards.com/thread/112/raspberry-pi-install-openhab-mosquitto

    Re: edit files

homeautomation.proboards.com/post/2251/thread

[chehre]

Thank you for the suggestions.

I am very glad to say that my first node (Full DHT End Node (except for the push button which I will link a channel on OH so device 40 can work)) and the Gateway is now good and running.    Amazing detailed step by step instructions. Thank you.

I will later (in about 10 days) write a wholesome post of [ what I remember of ] the process with links to threads and other sources on the net that helped me out, so this thread may be useful for some beginners.

As I'm reading other nodes' threads, I wonder if the OpenHAB configuration instructions given there are good to go with OH3!


I will read a few more of the available nodes and then start trying them. 
As I'm sure I'll bump into troubles, I'll be back in a few hours.

[papa]

chehre, I'm very glad to hear that DIY Home Automation things have started to work reliably for you.  You have accomplished a very big hurdle that should serve you well in future projects.

Yes, it would be great for you to document what got you though previous difficulties.

chehre: "other nodes' threads, I wonder if the OpenHAB configuration instructions given there are good to go with OH3!"

papa: Unless so indicated, those threads are not fully adapted to OH3. However, not much needs to be changed. Report what node thread you want to work on & I can help note adaptations that need to be made, even update the thread.

[chehre]

Thank you Papa for helping me out, I will have the documentation of my process by pointing out to your earlier posts in various threads that helped me the most and then I'll ask my questions in the next posts.

You have made it possible for any individual to walk in this road for achieving a home made home automation system. Thank you.

One key ingredient is to have patience. You will eventually overcome all the challenges.

All colors of my posts' text that are other than black are links to the posts and threads in this forum and resources on the Internet.

I had problems uploading sketches to the Seeeduino V4.2 Arduino Compatible board which got solved by the new update of Arduino IDE software.

Very important to have the correct length for Antenna soldered to the radio modules. All my Antennas are 0.5mm diameter and 80mm long wires soldered to my 868MHz 69HCW radio modules perpendicular to the module. 

I have my radio modules connected directly to the Seeeduino board without using prototype shields. I will move to using the shields on top of my Seeeduino boards as Papa has explained in this post. To do that I have to make a change in my wires. the wires I used are 24AWG with 0.5 core diameter while they should've been 22AWG with 0.65 core diameter. I couldn't find any 22AWG in my location and as for the result, I have loose wires in the Arduino headers which by bending them right out of the headers, I have them managed to not fall out but it's not a very reliable situation and to fix that, I have two ways; either wait for 22AWG to arrive from China and have them replaced to the current soldered wires or to have my already 24AWG soldered wires turned into Dupont connectors like it is done in this video.

I suggest you to test your radios the first thing, even if they are newly bought. Here is a very well detailed explanation of how it can be done.

After making sure of which radio modules are healthy to work with, it is time to start making the Gateway and the First node and check their connection on Serial Monitor (SM) of the first node while it is connected to the computer running Arduino IDE. 
For the first node, I followed this thread step by step until I had a full DHT node functioning and showing me results on the SM with having -60 RSSI strength in about 10 meters away with multiple walls on the way. 

The main point of making this project is to access to a [control and/or monitor panel] in OpenHAB User Interface (UI). To achieve this, the bi-directional communications of RFM modules passing the Arduino node based data packets need to be continued to the openHAB. This happens by the Ethernet (Arduino) or WiFi (ESP32) Gateway forming those data packets into MQTT topics. Source, read the last part of the readme.md at Computourist's Github

A computer (Raspberry Pi in my case) must have the openHAB Operating System (OS) and a MQTT Broker (Mosquitto for example) installed on it & be connected to the Internet modem via Ethernet cable. An Arduino Gateway will also be connected to the Internet modem with an Ethernet cable connected to the Arduino Ethernet Shield which is inserted on top of the Gateway's Arduino compatible board. Or an ESP32 Gateway will connect to the Internet modem via WiFi.

OpenHAB has its OS called openHABian installable on a Raspberry Pi using a micro-SD card. 

Having the Raspberry Pi connected to the modem, I accessed it via SSH protocol using Putty software.

In the configuration panel of openhabian, you can install the MQTT broker (Mosquitto) directly to the Raspberry Pi.

It is important to have a Static IP address arranged for the Raspberry Pi in the settings of your Router.

Next, in an internet browser, you can enter the IP address of the computer hosting the OpenHAB OS & thereby, access and start configuring your OpenHAB UI. An early thing to do is to install a MQTT binding in openHAB.  When the node data packets are converted to MQTT topics via the Gateway, they will be sent to openHAB on the Raspberry Pi. With openHAB having the MQTT broker (mosquitto ?) & MQTT Binding that will draw the rest of the line for those data packets (MQTT topics) to reach openHAB UI. As this whole communication is bi-directional, both monitoring (sensor data/ actuator status) and controlling of those sensors and actuators is possible through the UI.

Very important threads that must be read and understood for these steps are as follows:

Starting with OH3  and  The first node

RFM69 Gateway - Assemble and Program

By having these three threads completed, you will achieve a UI monitoring of your Home Automation System.

After that, you can add many sensors and nodes to be monitored and/or controlled as to your needs to your system by just following the nodes available in this forum and following the provided steps in configuring each node and its devices (sensors - actuators) to the openHAB UI. 

I now have several nodes including reed switches, DHTs, IR-Flame, Servo Sweeping IR-Flame, Lights, Gas and next I'll add LCD, Email Notification, Water level and temperature, Away mode and more. 

Some of my nodes are wall-powered with 9V 1A Adapters connected to the DC jack of Seeeduino V4.2 boards and the rest are 9V DC jacked battery powered.

[papa]

Congratulations, chehre. I'm happy & proud that you have a great start on your DIY Home Automation. I'm glad I could help & I appreciate how you did your own research using my posts & other resources.

You also did a nice, responsible job of reporting what worked for you. I did tweak your post some, but it was very solid before I did that.

You did a good job of linking to my instructions on key steps. The linked video on Dupont connectors was a helpful find that covers the key points.

It's good to know that a Seeeduino V4.2 Arduino Compatible is an option for nodes & gateways IF a current Arduino IDE is used to program it.

            About making more nodes:
 
Many of my node projects for sensors & actuators should be OK as is for hardware & firmware. Such projects document openHAB 2.5 configuration. However, they should be fairly easily adapted to openHAB 3, if you keep the following in mind:

1) My openHAB 2.5 configurations often refer to PaperUI. For openHAB3, similar configurations are done in Administration. In a brower, go to localhost:8080 & be logged in to openHAB administration. Then click Settings which then gives links to configuring Things, Bindings, etc.

2) Except for using settings/Things instead of PaperUI, configuring Things should be similar for OH3 as in OH2.5. If you use text files to configure Items, (unlike for OH2.5) OH3 needs the node Thing's UID.

In the localhost:8080/settings/things/ list click on the name of a node's Thing. Near the top of the resulting page is a line that says "Identifier" & just to the right is a small "stacked pages" icon. Hovering the mouse pointer over the icon displays "Copy UID" Click the icon & then you can paste the node Thing's UID where you need it in an Item's text configuration.

            Example of converting my OH2.5 Item text configuration to OH3:

        I previously had an OH2.5 Item for a node's signal strength   (Note: I then used an embedded mqtt broker instead of Mosquitto.):

String Node05RSSI "Node05rssi (db)[%s]" <network> (Nodes) { channel="mqtt:embedded-mqtt-broker:topic:mything:Node05Channel02" }

            My present OH3 Item for a node's signal strength:

String Node05RSSI "Node05rssi (db)[%s]" <network> (Nodes) { channel="mqtt:topic:c08f02ca8d:b3a7c9ed64:Node05Channel02" }

                Note: You will get a node Thing UID different from my "c08f02ca8d:b3a7c9ed64"

Starting here in my OH3 thread, I work through configuring openHAB3 for a data node. That should help you know the needed steps.

                            Happy DIY Home Automating !!!

[papa]

chehre PM: "I want to be able to understand ... how the data get reformed as MQTT topics from Arduino format."

papa: I believe you could learn a lot by studying the Gateway sketch. In that sketch, search for "topic" & study the related code & comments. I tried to be generous with comments to help me & others understand.

Along side what you see about "topic" in the Gateway sketch, look at your openHAB's Thing/channel configurations for a node's related MQTT State Topic & MQTT Command Topic.

    For example, a node & Thing named Node05. For RSSI, the channel identifier is Node05Channel02

       For this channel ...

MQTT State Topic is home/rfm_gw/nb/node05/dev02