I’d really like to get around the port forwarding
… but, reading your posts, I don’t think you’re really talking about “port forwarding” (or not!)
I’m not trying to be pedantic… but your Google searching will be more productive.
So… Arduino to fetch a webpage (that’s the hard part)
… look at what’s in it
… do something, depending on what it finds
If the contents of the web page are predictably formatted, that should be fairly “so-able”.
It isn’t for the Arduino, per se, but a lot of the things you have to solve are incorporated in my FarWatchWatcher, which uses a PC at location “A” to look at a web page, and then put a message on its screen. Specifically, it looks at temperatures being posted on a web page generated by a FarWatch installation, which is on a differnt PC at location “B”, and then FarWatchWatcher produces a big panel flashing red/yellow/red/yellow… if the temperature at the remotely monitored premises is nearing freezing.
The programming behind FarWatchWatcher is discussed at…
That is written in Delphi terms, but, as I said, the general principles behind what the program is doing get covered as well.
What you want to do is also being done by Pachube users. I find trees in the forest at the Pachube site… and the “solutions” there might vary somewhat from your EXACT proposed way of doing things, but I’m pretty sure the information is in there somewhere. There are certainly many Arduino people there, although there doesn’t seem to be much overlap between those Arduinonauts and the good people here at the Arduino forum.
Much of the content at the following will seem irrelevant to your quest, but have a skim through it to orient yourself, and then have a look at the Pachube site.
Intro to Pachube:
Going back to…
“Arduino to fetch a webpage (that’s the hard part)”
Especially if you control the page it is going to fetch, and can phrase the question as follows, it might pay you to launch a new, more focused thread, as follows. (Even if you can’t control the page it fetches, getting the following sorted out will start you on your way to where you’re going…)
"Arduino read webpage?
"I want an unattended Arduino to periodically fetch a page from a web-server out there on the net. There’s some fixed-format text near the top of the page…
Temperatures from Timbucktoo
<!--FWDF:aa recreated 2009-08-->Hello Gentle Reader. File updated at....
Recent temperatures... oldest reading first. And, for registered users, OnOff1
72.5 F 32.0 F --at-- 21-Jan-2011, 06:45:54 1568692
73.4 F 32.0 F --at-- 21-Jan-2011, 06:50:56 1568725
73.4 F 32.9 F --at-- 21-Jan-2011, 06:55:56 1568751
"I want to pick up the “72.5 F”, and have it available in my Arduino in a string-type variable, from which I will do other tnings with it. The 72.5 will always be on the 13th line of the fetched web page.
"I want the Arduino to do this “all by itself”… I don’t want to set up a PC near the Arduino to fetch the page, and then pass bits of it on to the Arduino.
"(If you need a page to check answers to this post, feel free to use either…
“(At least one of them is usually available.)”
That question covers at least two things you need… how to ACCESS a page out there on the web, AND how to extract a small string from the fetched page.
I hope you WILL post that question, or a derivative… I wouldn’t mind knowing the answers myself! (And concentrating on one part of a bigger project often gets you more useful responses here in the forum.)