Custom made ethernet gateway based on atmega128

[axillent]

@epierre not me, @hek made

I'm using a standard sketch from 1.4.1 version of the Mysensors library
what i'm going to do is to add flexibility for multi-gateway setup

[Anticimex]

@axillent
Nice. On the topic of flash usage of ethernet gateways, I also struggle with fitting signing support to an ethernet GW. I will eventually succeed, but it will leave virtually no room for other additions (at least with DEBUG enabled). So my question to you is: will you make your additions to the GW software (if any) switchable (if they add to the codesize)?
Or will you simply state that a Ethernet GW with "multi gw support" is not supported on a vanilla Arduino Nano?

[axillent]

@Anticimex as such multi-gateway do not requires code size increase but will need a hardcoding : IP, MAC, radio channel or BASE_ADDRSS. You have to use different parameters for different gateway nodes, Otherwise it will be a conflict on Air or on Ethernet

My list of additional futures will require more flash and atmega128 is very sufficient for this:
I plan a serial terminal with a configuration menu. It will work like BIOS on any PC. The "BIOS" will be activated by a button pressed during power on circle. By connecting a computer to the serial connector (I'm using audio 3.5mm stereo jack) you will be able to interact with the "BIOS" menu.. Menu will allow to:

• switch between DHCP/no DHCP
• to see assigned IP
• to assign a MAC
• to assign an IP
• to set radio channel
• to set BASE_ADDRESS
• to display current configuration
• to test ethernet and radio
• to see statistics
• to switch ON/OFF serial debug

[Anticimex]

@axillent
Ah, I see. It makes sense that the routing logic updates are to the controller(s) in that case. I like it. Especially since nothing prevents existing gateways to be added to this topology without modification :)

[axillent]

it got been print-cased)

this is in progress the development of gateway #2

[axillent]

instant made PCB is ready to be soldered

[marceloaqno]

Great Job! What are you using for the power supply?

[axillent]

@celonunes thanks!

on the photo you can see a black square part, it is a transformer
after transformer i have a bridge rectifier, one step-down based on MP2359 to get +5V
and other step-down base on NCP1529 to get 3.3V from the +5V

[axillent]

the schematics

[RJ_Make]

@axillent I just noticed 2 push buttons in the schematics? Is one a reset?

[axillent]

@ServiceXp atmega128 provides 53 I/O pins, I had to use at least some of them)))

I have no exact application for both buttons but probably will use them somehow in extended version of the Ethernet Gateway

[epierre]

why not use a photon ? it is $19 and already has the wifi ?

[axillent]

@epierre cortex is a nice thing but currently not supported by Mysensors. Do you want to add the support?

we are looking for the gateway based on ESP8266, it is just $4 board including WIFI and powerful MCU

[epierre]

@axillent I'm currently supporting my scripts on both arduino and spark.io to avoid everybody reinventing the wheel. Hopefully spark.io is more a hardware provider, meaning they design and implement hardware of their own they afterward sell, or sponsor through indiegogo. They also already have a could cum IFTTT already working.

Currently mysensors is too much linked to the vera although it is opening up. With a gateway that would be automatically wifi or wired, as you plan to do, that would change this.

I understand the approch for a cheap board, but I guess that you would need more components in you BOM that just the ESP8266 plus some soldering on a board ? (I don't speak of this nice russian transformer ;-) but that would kill many people in between just soldering, no ?

[axillent]

@epierre nice value arduino provide is that you can do nice things with low entry barrier and without soldering
Mysensors is intend to use this value as much as possible.

"Solder or not solder" is a personal decision and mostly subject of the fan.
At least for me it is fan
as for device from this topic it is not share of the schematics, it is just share of a fan)
russian transformer is part of it (i have a german one but it is too weak for this particular application)

as for ESP8266 - 4$ is the cost of a ready to use module. The only missing thing is radio, you will need to connect 5 wires to radio,
your BOM is simple - ESP module, nordic module and power supply
should be simple even without a special Mysensors board.
I see a good potential here

also I see a good potential on a future network topology discussed in a separate thread, I'm going to test myself an installation with multi hardware layer multi gateway MySensors network

[epierre]

@axillent which is something I actually do with all deversing into domoticz (vera, mysensors, spark core, webcam), and have an uniformized access through imperihome.

I'm very interrested about the wifi capacity if we cannot achieve some level of security within rf24.

[axillent]

I got an idea to improve my gateway by adding 433MHz receiver
I'm succeeded by adding it into the same dimension

As discussed with @hek it will be other version of EthernetGateway sketch able to handle both NRF24 and RF433 reciever

Just a small change to schematic

[Anticimex]

@epierre About security within rf24 we are close. I have implemented and verified HMAC-SHA256 signing. I just need some more time to implement support for a pure software-alternative to the ATSHA204 as well and my "offering" will be complete. Check the security thread (I will post my update there once finished).

[epierre]

@Anticimex This is good news, that would make us a bit safer... next step will be two ways SSL encryption ;-)

[Anticimex]

@epierre ha! Well, whoever wants encryption, feel free to do it :) I see no need so I'm skipping that though. I am fine with somebody potentially reading the sensor values and instructions I transmit. What concerns me is if somebody could fool my system and inject their own commands. But with my signing, I challenge anybody to try ;) (and I publish full sources)