Ethernet Confusion Pic Web Server Question

[shawn]

Hello,
A couple questions for ya all.
First of all, I want to be able to build a small web server using a pic. I want to be able to put graphics on the pages. No large file graphics but I want to be able to store alot of them. I also want to have data points displayed on my web page (pages) that are updated in real time without reloading the whole page. I currently am using an industrial web server called an Ilon but they are about $850.00 and they do way more than what I need and are way too expensive. They have about 64MB of flash memory to store web pages but I think I could do with less than 10MB. I send data to the web server via a modbus rtu controller that you all helped me with.

Is this even possible, I have read about every post on this forum about ethernet related stuff and to tell you the truth I am a little overwhelmed. I like the idea of the xport , connectone, and the tibo, but they dont seem to have very much memory for web pages. Is there anything else out there like these devices that have more memory. Is there any other devices like these out there that are reasonably priced and have more memory. Or maybe something that memory can be added to. Of all the posts out there not many seem to have any end results. I read the nuts and volts post but did not really understand it.

If this is possible I will read more into the posts but I am exhausted from the reading. Maybe I am not using the right key words for the search.

My dream is to hook a pic to a sd card and a ENC26J80 and create a simple web server.

Am I crazy?

A while back when I started looking into this I found a post where the html code was put into a lookup table inside the pics flash memory I believe. But I could not find that example again.

Thanks
Shawn

[lester]

You might be looking for this post http://www.picbasic.co.uk/forum/showthread.php?t=10973 you'll need to PM the user to get the low down as they did not post much more information.

but a google search will bring up many more solutions

[HenrikOlsson]

Hi,
I'm FAR from an expert on web, html etc but I think the real hurdle to overcome is the realtime updating. As far as I know standard html doesn't support that. The server can trig a refresh of the page but that's not what you want. If my understanding is correct you need to use what's called AJAX, I currently have NO idea what that actually involves but I think it is what you need to look into to get "realtime" updating.

I've been working on my PIC/W5100 setup but, apart from the realtime update, the problem with that as it's currently sits is how to access the graphics files etc from external memory. I haven't got around to implement any sort of external memory yet and to tell you the truth I wouldn't know where to start in order to implement a complete file system - which I believe would be needed in your case. MELABS have a FAT filesystem "driver" that might be the key to access SD card etc but I've never used it.

However, there are devices which allows you to access a SD-card or USB-stick etc formated in FAT32 (and perhaps even NTFS) via a simple serial interface. It would allow you to just copy the content to the media using your PC and then have your PIC read it via UART or SPI or whatever interface the particular device has and feed. For rapid developmement perhaps something like that would be the key.

Well, just some random thoughts.....
/Henrik.

[amgen]

I have learned a few things playing around, if you just continously spit out data from pic and use HTTP:// (your IP, local or WAN and port), different browsers display/render differently but HTTP1 keeps connection open (for a long time, maybe indefinitely). Opera browser seems to work well. Anyway, the data just streams until stopped.


On Opera, you can right-click.....reload.
Just starter stuff.

Don

[shawn]

Henrik,
Are you still working on this project? Using the Arduino Ethernet shield with AMICUS18 (Joint forum project?)

It looks very interesting, you have put a lot of thought into it. The way you have it structured in that post looks as if one could read that out of a SD card instead of putting it into program memory, or ram. Maybe even an I2C eprom, although I think eproms are slow, I may be wrong on that though.

I was thinking that realtime updating could be done with java script. Not real sure on that either, I have heard of AJAX and even read about it a little but I did not really understand.

I think I may tag along on that project or at least try it. I probably will not do the AMICUS18.

Shawn

[HenrikOlsson]

Hi Shawn,
Yes, I'm still working on it but not so frequent. The AMICUS18/Ethernet shield served well as an initial development platform but I've since designed my own board so I have the intention of continuing the project. The basic idea was, like the title says, some kind of collaboration but the interest seemed pretty low, it would be cool if you jumped in!

As you know the Ethernet shield contains a SD-card holder but on my own board I opted for a serial FLASH memory (SPI) instead. The problem/issue/hurdle is to handle the "filesystem", I mean it's probabaly not going to take much to get the current example going with external memory but you want to be able to download more advanced pages with multiple files etc, from the PC to the memory. I haven't given it enough thought yet.

Like I said, if you're interested please do jump in!

/Henrik.

[Ioannis]

I have no experience in such designs but I jump in to help if I can and learn too...

Can you squeze the graphics more and have less memory requirements, so that a Tibbo or other similar device be used?

Ioannis

[shawn]

Ok, I'm just about onboard with the PIC/W5100 setup. I'm still kicking around the thought of using the ENC28J60 chip. To me right now I'm thinking the only main difference is that the ENC28J60 doesn't do stack and the pic will have to handle it. That is a disadvantage because I don't really want to deal with the stack. And the W5100 will handle all stack and handshaking. I'm wondering what the disadvantage of using the W5100 is? Maybe the through put is not as good when using the ENC28J60. Both are spi devices so they should both work as fast as you can dump data to them.

Yes I am going to order some W5100 Monday.

I am going to jump on the band wagon. However I may trip and fall off.

Shawn

[HenrikOlsson]

Hi Shawn,
Yes, the W5100 handles the TCP/IP stack while on the ENC28J60 you'd have to code the stack (too) in PBP. For me, being an ethernet rookie, it was a given especially conciddering the small difference in price. One drawback is its bloody tiny.... 0.2mm legs on 0.4mm pitch.....

There's now a W5200 which is also an SPI device (unlike the W5300) but with 32k buffer and 8 simultaneous sockets. I've only looked at the datasheet brifely but it looks very simmilar to the W5100 commandwise.

Looking forward to hear about your adventures!

/Henrik.