Re: Embedded Ethernet

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.arch.embedded
Subject	Re: Embedded Ethernet
Date	2017-10-16 23:45 +0200
Organization	A noiseless patient Spider
Message-ID	<os39ab$gs2$1@dont-email.me> (permalink)
References	<oq3bj1$btg$1@dont-email.me> <os27k4$eq3$1@dont-email.me> <os2b4f$a09$1@dont-email.me> <os2kn9$gqd$1@dont-email.me>

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On 16/10/17 17:54, pozz wrote:
> Il 16/10/2017 15:10, David Brown ha scritto:
>> 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).
> 
> Thanks for sharing your experience.
> 
> 
>> 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.
> 
> Good suggestion.
> 
> 
> I have other two doubts.
> 
> RTOS (Free-RTOS) or not? I usually don't use RTOS and I never found it 
> is necessary in my applications. However TCP/IP, HTTP server and a 
> filesystem management could be tricky without an OS.
> 
> I studied the contrib example httpserver_raw in lwip project (an HTTP 
> server without an OS). It uses a script (makefsdata) to create a virtual 
> filesystem as a C source code. Is it ok for simple web pages?
> 

An RTOS is not necessary for a web server.  Use one if you think it 
makes things easier for you, or not if you don't.  FreeRTOS is probably 
the most popular RTOS around, and is a good choice.  You can use LWIP 
with or without FreeRTOS.

In my most recent project with a webserver, I used LWIP but no RTOS.  I 
used a similar principle to makefsdata, but with my own scripts for 
putting the static content files into C const arrays of data.  I am 
quite happy making such scripts (in Python), so that suited me - but I 
am sure the LWIP demo and makefsdata will work fine too.

> 
> The other question. What about dynamic content? The example seems show 
> only static content.
> 

I handled that with JSON files.  So my static index.html file has 
(static) javascript, using jQuery, that regularly polls the board 
webserver for a file "data.json".  This is generated dynamically 
(basically just a big snprintf statement with the required data added), 
and the javascript running on the client then puts the data in the right 
places in the html.

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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