Wireless network, broadcast messages.

Discussion in 'Embedded Systems and Microcontrollers' started by Dyslexicbloke, Jun 13, 2017.

  1. Dyslexicbloke

    Thread Starter Distinguished Member

    Sep 4, 2010

    I have a thread running, above, discussing a wired network for home automation and I dont want to duplicate the content so in this thread I only want to address 1 specific issue...

    Assuming I want to use Arduino, many of them, probably nano's, how might I go about getting any device to broardcast data to all other divices without using multiple messages targeted at single addressed devices.

    I will want to use modules not build radio boards.
    WiFi is an option only if the TCP stack is not in the Arduino, given the processor overhead of implimenting that.
    Mesh would be nice but probably isn't a requirement, particularly if utilising standard WIFI routers. as multiple routers running WDS will give me the coverage I need. UDP?

    Packets will be simple, and relativly short, probably 10 bytes or less, excluding headers, and scheduling will be required to ensure that priority information makes it onto the network quickly... That however is essentally a protacol issue and will come later.

    One key point... I do not want a master/server. All nodes will need to vie for TX time based on message priority.

    I am assuming everything will have to be buffered and some sort of time slot allocated for TX as I have no idea how colission detection works on wireless networks. Happy to learn though.

    If I could achieve a fast half duplex serial link, where any TX was received by all RX that might work.

    Reading now but need a leg up.

    I thought bI was committed to going wired but too many folk on several boards are questioning that decision for me to blindly ignore the possibility just because I dont fully understand the concepts... Yet

    Thoughts folks?

  2. KeepItSimpleStupid

    AAC Fanatic!

    Mar 4, 2014
  3. Dyslexicbloke

    Thread Starter Distinguished Member

    Sep 4, 2010
    Thanks, looking now....
    Also wondering about 433MHz tranceevers, cant help thinking that talking to cheap radio sockets might be advantageous.

    HC-12 ?

    I could probably remote program with those with a little mucking about...
  4. Dyslexicbloke

    Thread Starter Distinguished Member

    Sep 4, 2010
    Wiki... Interesting, despite all the big words :eek:

    So I suppose it comes down to a choice... use a simple radio and deal with all the complexities of c hopping up time and or changing freequencies or used a module which handles all that and impliment a protacol that supports broardcasts of some sort.

    My gut is telling me to go with WIFI based kit because, once configured, which I suspect will be no easy task, it should be easier to work with.
    I like simple but I think, based on your suggested reading, that I m ay be oversimplifying or at the very least not apriciating all the issues involved in mucking about with dumb radios.

    Anyone played with ESP8266 (Suggested earlier on the other thread)
    The things look very capable but it isn't something I have any experience of, although I am comfortable with TCP network configuration in general.

    It also occurs to me that given the speed I could potentally use accknolidghed packets although that brings me back to some sort of master/server which I was trying to avoid.

    Interesting, perhaps testing is the only way to know... and just when I thought I had decided to wired with a c custom protacol.

    Very interested to here thoughts with respect to the very diferent approaches ESP8266 / HC-12

  5. John P

    AAC Fanatic!

    Oct 14, 2008
    If you want to keep it simple and if your data rate doesn't need to be very high, I think you could use the timing aspects of the network that Roman Black described, which he modestly called Blacknet:

    For Roman Black it was "many devices attached to one serial bus wire" but for wireless, it would be "many devices capable of transmitting on the same frequency".