Complete Beginner Help for Ethernet Node

[keshin]

Hey guys im completely new to the world of home automation but im trying to get my head around it all (im more hardware than software)
I hope this is okay to post in here and hopefully someone may be able to steer me in the correct direction. 

im still learning to code arduino so far i have managed to get basic things happening based purely on i/o pins 
what im hoping for is if anyone can help me get over this next hurdle (iv read so much im confusing myself)

what i have so far:
*i have an arduino mega with ethernet sheild
*i have a 16 relay board 
*im using a windows 7 pc and have installed openhab and mosquitto onto it 
*openhab connects to ios openhab app 

where i am lost
*i cannot work out what code or how to get the arduino to communicate with open hab and let me use each i/o i set as a different switch etc in openhab


is there any chance anyone has a basic sketch or something with notes that for example would allow the arduino to communicate with open hab and make a switch for led pin 13 to turn on, from that i think i would be able to understand what parts identify the arduino to openhab and what parts identify a switch and output in arduino.


please note i do plan on using esp8266's down the track but for now i wish to start with the ethernet 

Thanks to any help im given
also if its okay i will compile everything i learn here and edit this first post to show the very basic noob getting started instructions to help others in the same spot i am now.


attached is a crude drawing of my basic idea i wish to start with also i am unsure if my switch idea will work or not at this stage functionally it works, however for eg if i attached a light to the relay i want to be able to have openhab understand which state the light is in, so if i push the button it turns the light on, then if i went into the app on my phone it would know its turned on and id be able to switch it off.

[papa]

Welcome, keshin, to the thrill (& sometimes frustration, especially at the beginning) of DIY Home Automation.

This forum's members have helped other beginners & perhaps we can help you. I sympathize with your confusion. This stuff is a lot to take in.

By installing OpenHAB & Mosquitto, you have taken care of those important steps.

    You said, " i do plan on using esp8266's down the track but for now i wish to start with the ethernet."
In fact the ESP8266 devices documented on this forum are the only ones that communicate DIRECTLY with OpenHAB over (WiFI) Ethernet
   As you probably read on this forum, those devices are a great way for beginners to get started.
The threads on this forum's ESP8266 Board offer hardware recommendations / builds, software (that communicates via Mosquitto), & OpenHAB entries.

This forum's other approach uses a DIY Gateway. Via Ethernet, the Gateway connects to & communicates with a computer hosting OpenHAB & Mosquitto. Via an RFM69 radio, the Gateway communicates wirelessly with DIY end nodes via the node's RFM69 radios. Thus the Gateway is a two way communication bridge between OpenHAB/Mosquitto & the RFM69 end nodes.

Using this forum's approach, one can have both ESP8266 devices & RFM69 end nodes communicating with the same OpenHAB user interface.

[papa]

What our forum offers should allow you to accomplish what you want, BUT (other than OpenHaB / Mosquitto ) ...

we take a different approach than what you are trying.

For example, the thread Building an RFM69 Home Automation Network (Beginners ??) will guide you through building / programming an RFM69 Gateway & RFM 69 DHT End Node & have them communicating with OpenHAB. With a pushbutton & on an OpenHAB User Interface, you can toggle an LED's state. An OpenHAB item will track the LED's state. I believe something similar could be done to toggle relays on your relay board.

[keshin]

thanks so much for getting back to me,

sorry for the basic questions, Am i understanding correctly that

1. nodes are each device (thats used for switching, sensors etc) and the esp8266 is basically an arduino with wifi.
2. that openhab can only talk wirelessly through the network not through a fixed lan cable to an ethernet sheild.

basically i guess my question is if i was to replace my ethernet sheild with a esp8266 on my arduino mega, would that work then?
i will be using the esp8266 for most things but i was hoping i was able to use the arduino mega with the 16 relay board attached as a centralized unit.

Again thank you and i apologize for the basic questions, this is very new to me

[papa]

You're welcome. No need to apologize. We all start somewhere.

keshin: "1. nodes are each device (that's used for switching, sensors etc)"
papa: Yes, nodes are such devices that communicate with OpenHAB, as you say for switching or sensing.
As I wrote earlier, ESP8266 nodes communicate with OpenHAB / MQTT directly via WiFi

As I also wrote earlier, "Via Ethernet, an RFM69 Gateway connects to & communicates with a computer hosting OpenHAB & Mosquitto. Via an RFM69 radio, the Gateway communicates wirelessly with DIY end nodes via the node's RFM69 radios. Thus the Gateway is a two way communication bridge between OpenHAB/Mosquitto & the RFM69 end nodes."

keshin: "the esp8266 is basically an arduino with wifi." papa: An ESP8266 device has a different processor than an Arduino compatible, BUT we can program it like an Arduino, using the Arduino IDE with other board information installed in the IDE.

keshin: "2. that openhab can only talk wirelessly through the network not through a fixed lan cable to an ethernet shield."
papa: Hmmm, it's maybe the other way around that so far our forum's nodes communicate with OpenHAB either directly through WiFi or indirectly via RFM69 radio & the RFM69 Gateway." OpenHAB can communicate with a wide variety of things as long as we activate an OpenHAB binding (like MQTT) that will work with our devices' programming.

keshin: "if i was to replace my ethernet shield with a esp8266 on my arduino mega, would that work then?" papa: I don't honestly know. It's certainly beyond my knowledge & ability.

keshin: "i was hoping i was able to use the arduino mega with the 16 relay board attached as a centralized unit." papa: So far on this forum, we have not done that. Perhaps the Gateway or ESP8266 code could be adapted & used to program the mega to communicate (as a node) with OpenHAB via Ethernet cable. Perhaps down the line, an RFM69 radio breakout board (& programming) could be added to the mega so it is both an RFM69 Gateway & communicates with the relay board. I've never used a mega. The mega's larger memory would at least provide the space.

papa: In the long run, I believe your home automation network will be able to do more & you would have a better understanding if you would do one beginning ESP8266 Wifi device & then the beginning RFM69 network of Gateway & DHT end node. You would have the start of an OpenHAB hybrid network of ESP8266 & RFM69 which opens many possibilities, several of them documented on this forum.  Ethernet cable devices limit where you can put them.  Wireless devices can be placed in so many more positions.

It would probably be at least a few weeks before I could look into a node connected via Ethernet shield & cable. Perhaps someone else on the forum has something or would be willing to tackle it.

In the meantime, I again suggest you get your feet wet with our beginning ESP8266 & RFM69 devices.  You could study (again?) the thread, OpenHAB Home Automation Overview - RFM69 AND ESP8266 & follow the links to do the first ESP8266 & RFM69 projects.

[keshin]

thank you heaps for your reply i will start off ordering a couple of esp8266 and rfm69 devices and have a go at that thread and projects

i already have a couple of arduino megas an the relay board i will put those aside for now

[papa]

keshin: "i will start off ordering a couple of esp8266 and rfm69 devices and have a go at that thread and projects"

papa: When you order Arduino compatibles for those projects, be sure you notice the caution to get compatibles (like the Buono Uno) that use 3.3 volts (NOT 5 volts) not only at the 3.3 volt socket, but also at the digital pins (D2, D8-D13). Unless gets the RFM69 radio on a breakout board, the RFM69 radio will be damaged by digital pins that operate at 5 volts.

[papa]

keshin, I still think that your home automation will be more robust if you make our forum's initial ESP8266 & RFM69 projects work & then build from there. At the same time, I can see some usefulness for a node that uses Ethernet to communicate with OpenHAB. Curiosity got me & I grabbed some time to work on this.

keshin: "i have an Arduino mega with Ethernet shield ... Does anyone have a basic sketch or notes that would allow the Arduino to communicate with openhab (over Ethernet) and make a switch for led pin 13 to turn on, from that i think i would be able to understand what parts identify the arduino to openhab and what parts identify a switch and output in Arduino."

papa: I believe the following will answer your request. (But again please, keep working on ESP8266 & RFM69 projects because this Ethernet node will work along side those projects.)

        The rest of this thread has been moved to a new thread called "An Ethernet Node"