[Tutor] Telephone app

[Alan Gauld]

"David Hutto" <smokefloat at gmail.com> wrote

> By flow through, I mean that the phone has one of 2 states(on the
> hook, off the hook), and three sub states(on the hook/off the hook 
> in
> use/off the hook not in use).

Umm, no. Much more than that.

> On the actual phone we pick up the receiver, or press the button on
> the cordless to receive, but the line is always connected, meaning 
> it
> stops at the phone(terminal). I pick up the receiver, and transmit a
> series of specific tones which indicate the area code, trunk number
> and extension(if I remember this correctly, it's been a while since 
> I
> studied the phone itself).

You are describing an anlalog phone but with a greatly oversimplified
model. (no dialtone/busy tone/party-line detection etc)
You need to do a lot more research into how analog phones work and
you will need some hardware to interface to it - weither a dedicated
CTI card or a modem.

> So I think my main question is what modules might be relevant to 
> doing
> this? And should I be thinking of it any differently than a USB port
> which has 4 pins two data(+-), and two dc current(+-)?

USB is a digital serial bus, phones are analog. They are not at all
alike (quite apart from the voltage issues Bob mentioned).

-- 
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/