Re: Busy flag and Dial tone

From: Ken Taylor (ken_at_home.nz)
Date: 12/26/04 

Date: Sun, 26 Dec 2004 17:26:41 +1300

"derek" <dereklai2k@yahoo.com.hk> wrote in message
news:1103992000.345346.48920@z14g2000cwz.googlegroups.com...
> Hi,
>
> Do anyone know how to detect busy flag and dial tone of a 2 wires
> telephone line by MCU and telephone related IC?
>
> Thanks!
>
A call progress detector would do the trick, such as an MX663:
http://www.cmlmicro.com/Products/WTelecom/FX663.htm
or a modem chip would suffice, such as a CMX867 -
http://www.cmlmicro.com/Products/WTelecom/CMX867.htm

I just grabbed these examples in a quick search, you want to see what is
available once you know the key terms to search for. A modem chip may be
more easily obtainable than a call progress detector, though the latter
would, at first thought anyway, be easier to program. In a pinch you could
get a PIC with a modem built-in and use that.

Ken

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