Loading ...
Sorry, an error occurred while loading the content.

Can I interface the NSLU2 to an EIA-485 bus?

Expand Messages
  • Anssi Porttikivi
    If I have some home automation equipment that is controlled via a proprietary protocol on top of serial EIA-485 (RS-485) bus, can I do a hardware hack to the
    Message 1 of 4 , Jun 13, 2008
    • 0 Attachment
      If I have some home automation equipment that is controlled via a
      proprietary protocol on top of serial EIA-485 (RS-485) bus, can I do a
      hardware hack to the NSLU2 to interface to that? I am actually
      planning a commercial product based on this, and we have some
      resources to buid it, if it makes sense.

      Or does anyone have any ideas of another cheap, general purpose, easy
      to program platoform for controlling home automation?
    • Sam
      ... a ... Just an aside if you dont know already - The NSLU2 is discontinued, and therefore no longer being produced So the chances of being able to source
      Message 2 of 4 , Jun 13, 2008
      • 0 Attachment
        --- In nslu2-general@yahoogroups.com, "Anssi Porttikivi" <app@...>
        wrote:
        >
        > If I have some home automation equipment that is controlled via a
        > proprietary protocol on top of serial EIA-485 (RS-485) bus, can I do
        a
        > hardware hack to the NSLU2 to interface to that? I am actually
        > planning a commercial product based on this, and we have some
        > resources to buid it, if it makes sense.
        >
        > Or does anyone have any ideas of another cheap, general purpose, easy
        > to program platoform for controlling home automation?
        >

        Just an aside if you dont know already - The NSLU2 is discontinued, and
        therefore no longer being produced

        So the chances of being able to source many for a commercial product
        for the longer term are quite slim

        Just a heads up!
      • John
        ... You can add a USB-to-RS-485 hardware dongle to support RS-485 from a slug. The one that I use is the USB-COMi-SI . You don t mention which proprietary
        Message 3 of 4 , Jun 13, 2008
        • 0 Attachment
          On Fri, Jun 13, 2008 at 10:15:37AM -0000, Anssi Porttikivi wrote:
          > If I have some home automation equipment that is controlled via a
          > proprietary protocol on top of serial EIA-485 (RS-485) bus, can I do a
          > hardware hack to the NSLU2 to interface to that? I am actually
          > planning a commercial product based on this, and we have some
          > resources to buid it, if it makes sense.

          You can add a USB-to-RS-485 hardware dongle to support RS-485
          from a slug. The one that I use is the "USB-COMi-SI".

          You don't mention which proprietary protocol but it is likely
          that you would be responsible for the software to implement it.
          You can control the RS-485 I/O on a slug via programs written in a
          language of your choosing: C or Python or whatever.

          > Or does anyone have any ideas of another cheap, general purpose, easy
          > to program platoform for controlling home automation?

          There are lots of cheap single-board computers with good serial I/O
          support. What is unusual about the slug is not its feature set but
          that it comes complete with power supply and a nice consumer-friendly
          case.
        • tbering2002
          ... You could also connect a TTL to RS-485 transceiver chip to the onboard serial port on the NSLU2. That would be a pretty good option, as it would let you
          Message 4 of 4 , Jun 16, 2008
          • 0 Attachment
            --- In nslu2-general@yahoogroups.com, "Anssi Porttikivi" <app@...> wrote:
            >
            > If I have some home automation equipment that is controlled via a
            > proprietary protocol on top of serial EIA-485 (RS-485) bus, can I do a
            > hardware hack to the NSLU2 to interface to that? I am actually
            > planning a commercial product based on this, and we have some
            > resources to buid it, if it makes sense.
            >
            > Or does anyone have any ideas of another cheap, general purpose, easy
            > to program platoform for controlling home automation?
            >

            You could also connect a TTL to RS-485 transceiver chip to the onboard
            serial port on the NSLU2. That would be a pretty good option, as it
            would let you use the NSLU2 to prototype your code, and then switch to
            a different platform when the concept is closer to production.

            Warning: at least on my NSLU2 units, the boot loader listens for
            traffic on the serial port at startup. As such, with a half-duplex
            serial connection, the NSLU2 will hear its own traffic and abort the
            boot process. You will need to gate Rx inputs to the slug to a
            disabled (low) state for the first section of the boot process. This
            is easy enough to do, if you know to do it.
          Your message has been successfully submitted and would be delivered to recipients shortly.