Re: OFF-TOPIC: HTML to send data out a certain port
On Mon, 03 Oct 2011 10:56:36 -1000
Joel Roth <joelz@pobox.com> wrote:
> On Mon, Oct 03, 2011 at 02:32:15PM -0500, Kent West wrote:
> > Yes, off-topic, but you folks are the brightest group with which I'm
> > affiliated ....
> >
> > We're thinking of building a Debian-based web-server that offers up
> > a "remote control" interface for a smart classroom in a university.
> > We want a web interface so it'll be universal (particularly working
> > with mobile devices such as smartphones, iPads, etc.). This web
> > interface would allow the the teacher to control the various
> > multimedia devices in the room (projector, volume on the sound
> > system, doc-cam, DVD player, etc) just by bringing up the web site
> > on his Android phone, etc, and clicking hyperlink-type buttons. In
> > this way he can power up the projector, tell the projector to show
> > the signal from the laptop port in the podium or to switch to the
> > image from the document camera, crank up the sound system volume,
> > dim the room lights, etc.
> >
> > In order to do this, we have to convert the web clicks into infrared
> > signals going to the various IR-enabled devices, essentially
> > replacing the remote controls that came with the devices.
> >
> > Global Cache (http://www.globalcache.com/products/itach/models2/)
> > has devices that, as I understand it, will send out the various IR
> > signals to the various devices, based on ASCII commands sent to it
> > via a wireless connection.
> >
> > My problem is how to convert a click on a web page into the proper
> > code to be sent over the wireless network to the Global Cache
> > device. I don't have the Global Cache yet to play with, but I'm
> > trying to get a feel for how to do things before we start spending
> > money. The API documentation from their web site indicates it's a
> > matter of just sending the correct ASCII sequence out the web
> > server's TCP socket on Port 4998.
> >
> > Here's a snippet from their documentation that might help set some
> > background:
> >
> > >Commands are initiated by short ASCII string representing the
> > >command type. Typically, physical address and data information
> > >will follow. The structures of iTach commands are described in the
> > >following sections. Text enclosed in brackets (<text>) must be
> > >substituted by its ASCII definition. Multiple ASCII choices are
> > >divided by separator ( | ) characters.
> > >
> > >Note: Commands are case sensitive.
> > >
> > >Example: The network settings are queried with the get_NET command:
> > >
> > >get_NET,<connectoraddress>↵
> > >
> > >where;
> > ><connectoraddress> is 0:1 (network module address)
> > >
> > >The command ASCII string sent to the iTach is:
> > >
> > >get_NET,0:1↵
> > >
> > >Note: get_NET command is documented fully in section 5.1 below.
> >
> > Can anyone provide me a snippet of HTML (and/or related, such as
> > php, etc) code for sending an ASCII string (such as the above
> > "net_NET,0:1 <CR>") to TCP socket Port 4998?
> >
> > Better yet, can anyone also provide me a means of testing if I'm
> > sending to that port without yet having the hardware in-hand? Like,
> > if I manage to send data to port 4998, how do I know I sent it and
> > what it looks like on the other side?
Change the device to which you are connecting to localhost and 'netcat
-l -p PORT' is the appropriate incantation I believe.
> > And is this called "raw socket programming", or what? If I knew what
> > terms to google for, I might not need to bother y'all any more.
> >
> > Thanks!
>
> I think what you need is a web framework that lets you
> process HTTP requests generated by a user clicking on links
> submitting forms, activating buttons, etc.
>
> Any modern scripting language will have suitable web
> frameworks and socket communication
> libraries to accomplish what you want.
If I were doing it, I would use python to detect which button was
pressed on the last page and send a command out a socket, then
regenerate the page again. Python's socket libraries are very, very
easy - see http://docs.python.org/howto/sockets.html for a quick
rundown. Server side would make this nicer (IMHO), but it might be
*easier* to do it client side (the only real difficulty being the
client must be able/know how to connect directly to the controller).
The only real difficulty would be making it easily extensible.
Reply to: