Re: Embedded Ethernet

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.arch.embedded
Subject	Re: Embedded Ethernet
Date	2017-10-16 15:10 +0200
Organization	A noiseless patient Spider
Message-ID	<os2b4f$a09$1@dont-email.me> (permalink)
References	<oq3bj1$btg$1@dont-email.me> <os27k4$eq3$1@dont-email.me>

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On 16/10/17 14:10, pozz wrote:
> Il 22/09/2017 17:52, pozz ha scritto:
>> There are many MCUs with embedded Ethernet (MAC). It seems most of the
>> open-source examples are lwip-based.
>>
>> I have to design a board with one RS485 port and one Ethernet port. It
>> could be seen as a serial-to-Ethernet converter, where the protocol on
>> RS485 is proprietary. On Ethernet side I will contact a server (cloud)
>> with a protocol that must be defined.
>>
>> At the moment, I don't need to implement a server, only a simple client.
>>
>> Do you suggest some hw/fw platforms that you think are better than
>> others?
> 
> Another question related to embedded Ethernet.
> 
> If I implement a simple Web Server to remotely control the device from a
> standard Web Browser, I need some non volatile memory space to store web
> pages (html, css, images...).
> 
> It's difficult to estimate the amount of data I will need for "web
> server filesystem", however I think it's highly probable the internal
> Flash memory of MCU will not be sufficient.
> 

That depends entirely on the MCU in question, and the complexity of the
web page.  I have no problem with webpages in the MCU I am using (512 KB
flash).

Note also that static data, such as images, javascript libraries, html
files, can easily be taken from an independent webserver as long as the
client has internet access - maybe you need nothing more than a "loader"
index.html and dynamic json "files" on your internal webserver.

> So I need an external Flash memory. Of course I can use a parallel or
> serial Flash memory: parallel is faster, but it needs more space on PCB
> and more signals to route. Serial Flash are cheaper and simpler to
> integrate in the board, however they are slower... will it be sufficient?

Parallel flash is not necessarily faster - serial flash can run quickly
if you have a fast SPI.  If your MCU supports quad SPI, it is probably
faster than you can get with an external parallel flash.  Plus, the
serial types are smaller, cheaper, and more flexible (it's easier to add
more storage without changing the board design).

Note also that even if your static data is sent slowly, it only needs to
be sent once - the client will cache it.  Keep your dynamic data nicely
separated, and you'll be fine.

> 
> I saw some LPC MCUs have a SPIFI peripheral that lets you use a serial
> SPI Flash and see it in the normal address space. I think it is a nice
> feature.
> 
> Do you have other suggestions how to increase storage size for web pages?

Thread

Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-09-22 17:52 +0200
  Re: Embedded Ethernet mmm <m.colandrea@libero.it> - 2017-09-22 18:00 +0200
  Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-09-22 20:27 +0200
    Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-11-17 10:25 +0100
      Re: Embedded Ethernet Theo Markettos <theom+news@chiark.greenend.org.uk> - 2017-11-17 10:39 +0000
        Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-11-17 12:25 +0100
      Re: Embedded Ethernet "Boudewijn Dijkstra" <sp4mtr4p.boudewijn@indes.com> - 2017-11-17 11:36 +0100
        Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-11-17 12:54 +0100
      Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-11-17 15:23 +0100
      Re: Embedded Ethernet Mikko OH2HVJ <mikko.syrjalahti@nospam.fi> - 2017-11-18 11:29 +0200
  Re: Embedded Ethernet Joe Chisolm <jchisolm6@earthlink.net> - 2017-09-22 13:31 -0500
    Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-09-23 00:01 +0200
      Re: Embedded Ethernet raimond.dragomir@gmail.com - 2017-09-22 22:38 -0700
        Re: Embedded Ethernet raimond.dragomir@gmail.com - 2017-09-22 22:41 -0700
      Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-09-23 12:02 +0200
        Re: Embedded Ethernet Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-23 06:32 -0400
          Re: Embedded Ethernet Dimiter_Popoff <dp@tgi-sci.com> - 2017-09-23 15:31 +0300
            Re: Embedded Ethernet Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net> - 2017-09-25 13:07 -0400
              Re: Embedded Ethernet Robert Wessel <robertwessel2@yahoo.com> - 2017-09-25 15:31 -0500
                Re: Embedded Ethernet Dimiter_Popoff <dp@tgi-sci.com> - 2017-09-27 01:50 +0300
          Re: Embedded Ethernet Les Cargill <lcargill99@comcast.com> - 2017-09-28 20:07 -0500
        Re: Embedded Ethernet upsidedown@downunder.com - 2017-09-23 14:48 +0300
        Re: Embedded Ethernet Les Cargill <lcargill99@comcast.com> - 2017-09-28 20:06 -0500
          Re: Embedded Ethernet Joe Chisolm <jchisolm6@earthlink.net> - 2017-09-29 09:41 -0500
          Re: Embedded Ethernet upsidedown@downunder.com - 2017-09-30 18:49 +0300
        Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-10-12 11:26 +0200
          Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-10-12 12:46 +0200
          Re: Embedded Ethernet Joe Chisolm <jchisolm6@earthlink.net> - 2017-10-12 10:49 -0500
      Re: Embedded Ethernet Grant Edwards <invalid@invalid.invalid> - 2017-09-23 20:40 +0000
        Re: Embedded Ethernet Joe Chisolm <jchisolm6@earthlink.net> - 2017-09-23 19:24 -0500
          Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-09-24 13:28 +0200
  Re: Embedded Ethernet Les Cargill <lcargill99@comcast.com> - 2017-09-22 21:12 -0500
  Re: Embedded Ethernet Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2017-09-24 11:01 +0300
  Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-10-16 14:10 +0200
    Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-10-16 15:10 +0200
      Re: Embedded Ethernet pozz <pozzugno@gmail.com> - 2017-10-16 17:54 +0200
        Re: Embedded Ethernet David Brown <david.brown@hesbynett.no> - 2017-10-16 23:45 +0200
          lwip/httpd: how to return dynamic data [was Re: Embedded Ethernet] pozz <pozzugno@gmail.com> - 2017-11-13 12:11 +0100
            Re: lwip/httpd: how to return dynamic data [was Re: Embedded Ethernet] David Brown <david.brown@hesbynett.no> - 2017-11-13 14:14 +0100

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