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Electronics => Electronics => Topic started by: TaoBaiBai on January 06, 2013, 09:07:26 PM

Title: RS232 corded phone
Post by: TaoBaiBai on January 06, 2013, 09:07:26 PM

Hi

Anyone know how to connect a microcontroller to a telephone through RS232 to dial number? What phone has RS232 port？

Title: Re: RS232 corded phone
Post by: waltr on January 06, 2013, 09:31:20 PM

None.
What you need is a MODEM between the RS232 and the phone line.

Title: Re: RS232 corded phone
Post by: TaoBaiBai on January 06, 2013, 09:39:51 PM

Can you show me some of the modem and how does it work? Does it input the dial signal from microcontroller to the modem and the output end of modem is RJ11 which will go to phone. So the phone must has two RJ-11 port,one is for modem and the other is for dialing out?
 

Title: Re: RS232 corded phone
Post by: billhowl on January 07, 2013, 10:23:25 AM

(http://ecx.images-amazon.com/images/I/216V4YJK3NL._SL500_AA300_.jpg)(https://downloads.avaya.com/elmodocs2/definity/def_r10_new/easy_3/images/Modfrobo.gif)
Modem (http://www.amazon.com/V-92-External-RS232-Serial-Modem/dp/B000A6LEDG)

Title: Re: RS232 corded phone
Post by: jwatte on January 07, 2013, 11:20:09 AM

Quote from: TaoBaiBai on January 06, 2013, 09:39:51 PM

Can you show me some of the modem and how does it work? Does it input the dial signal from microcontroller to the modem and the output end of modem is RJ11 which will go to phone. So the phone must has two RJ-11 port,one is for modem and the other is for dialing out?

It's the modem that has two RJ-11 ports.
Yes, the modem just speaks RS-232.
These modems were used as late as 10 years ago for dial-up internet access. You should be able to find a used one really cheaply in someone's garage sale.