24 Mar
2007
24 Mar
'07
11:53 p.m.
my application anyway. What is the typical maximum
speed of such a device, be it antiquated (I actually
I think the ones we had (have?) over here were either 300 baud
full-duplex devices or the 1200/75 baud 'prestel' standard.
I think somebody tried to get an accoustic coupler working with a 2400
baud modelm ,but it was darn unreliable.
In fact, that's an acoustic modem. What I'd like to
implement is a "bridge" if you will between a modem
and a cellular device that would allow connection to
the internet. Ingenious, no? ;)
If your idea is to transmit and receive modem tones using a cellphone,
why don't you start witha handsfree kit for said cellphone. At least
you'll have audio I/O on the wires to the microphone and earpiece that
you can presumably make use of. It would cut out the accoustic coupling
part, with its attendant problems.
I'm not sure how the bendwith, etc, of cellphone audio compares to a
landline. You may still have baud rate limitations.
I think I did read of a module that was essentially a cellphonemodem. You
stuck a SIM card in it, it haf a serial port that took Hayes commands,
and you could dial up any other modem (cellular or landline) using the
cellphone network. I have no idea if it's still available or how much.
-tony