Re: DTMF dead?

Rich Grise <rich@xxxxxxxxxxx> wrote:

On Tue, 10 Jul 2007 22:56:39 +0000, Nico Coesel wrote:
"Joel Kolstad" <JKolstad71HatesSpam@xxxxxxxxx> wrote:
"Nico Coesel" <nico@xxxxxxxxxxx> wrote in message
news:469287fd.52824567@xxxxxxxxxxxxxxxxx
That is a very valid argument. But there many reasons (wiring,
connectors, transformers, code size, etc ) why ethernet doesn't fit in
this application.

You can still use a PoE controller IC even if you don't have "real" Ethernet
anywhere... they're really just your standard switching converter ICs with a
simple "protocol" thrown on top to let the controller "handshake" with the
power provider system.

But that still seems like an overkill for the project at hand. There
is an ethernet connected device acting as a bus master. Using internet
technology also comes with security issues so SSL or a similar
encrypted tunneling technique is required.
A proprietary bus is not easy to hack or interface (lets say it takes
more than a laptop with ethereal) and thus requires less security
measures. SSL alone takes about 90kB of flash and some processing
power.

Earlier in the thread, you were talking about DTMF. Now you're all the
way to SSL? What are you trying to accomplish?

I'm (co) working on a system that is primarily based on ethernet / IP
protocol. An antire system can consist of several thousand units (all
kinds of devices) in total. Some of the units need to be really cheap
and small to be economically viable.

For a particular type of unit there is a severe space constraint. So
there is a trade-off to take ethernet all the way to the smallest
units or place a master ethernet<->proprietary converter unit at a
convenient location and feed the smaller units with a proprietary
protocol.

Having to use SSL or not is just one of the trade-offs to choose
between standard ethernet or going proprietary.

I was hoping DTMF could provide a cheap and easy to design way to get
some communication going (thats where it comes down to in the end).
But I couldn't find any cheap chips. Worse, surface mounted DTMF chips
are even harder to find. That raised my question: Is DTMF dead? And I
think the answer is yes.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl
.

Relevant Pages

  • Re: DTMF dead?
    ... connectors, transformers, code size, etc) why ethernet doesn't fit in ... You can still use a PoE controller IC even if you don't have "real" Ethernet ... SSL alone takes about 90kB of flash and some processing ... And, if you've got a 2-wire system, I'd use AFSK before I used DTMF. ...
    (sci.electronics.design)
  • Re: DTMF dead?
    ... power provider system. ... is an ethernet connected device acting as a bus master. ... SSL alone takes about 90kB of flash and some processing ... protocol. ...
    (sci.electronics.design)
  • Re: Ethernet breaker
    ... > and disable individual switch ports as needed. ... Years ago I had some external hardware SSL ... Ethernet cable, and do the SSL work whenever traffic appeared on ... hardware in the box *and* to each other through some DPDT relays (i ...
    (comp.dcom.lans.ethernet)
  • Re: DTMF dead?
    ... connectors, transformers, code size, etc) why ethernet doesn't fit in ... You can still use a PoE controller IC even if you don't have "real" Ethernet ... power provider system. ... The less wires, the thicker each wire. ...
    (sci.electronics.design)
  • Re: Help Constructing Fictional Cross-Religious Movement
    ... >For the answer to the hermaphroditic connectors, see Token Ring, but ... What's Token Ring, a networking technology, got to do with serial ... ethernet was just coming into fashion. ...
    (rec.arts.sf.composition)