Maybe ne AD/DA chip, memory, and a signal processor?
But the signal processor need external components too...
WOW: Texas Instruments sell development boards with all this in a ready to
run PCB including Assembler, debugger and documents for only $99 !
Lust to add more memory (FLASH?) and the line interface, I think.

Only the programming left...

I think this is the right oppotunity if you want to learn signal processors!
(Myself have not had the time to play with them yet)
/Morgan

At 23:22 1998-02-01 +0100, you wrote:
>Hello all.
>
>My boss told me to build a circuit to be connected to the telephone line;
>I'm doing some preliminary research and I'd like some tips or suggestions.
>The circuit should be able to dial a phone number (DTMF or pulses), wait
>for an answer from a human operator (i.e. distinguish a voice from a busy
>line or other tones) and then recognize DTMF tones and reply with short
>pre-recorded messages (something like: "Press 1 on your telephone to do
>this, or 2 to do that").
>
>I've already built something using a Mitel 8870 to recognize DTMF tones,
>and I used an ISD1020 in another project to make my PIC talk over a phone
>line, but these were low-cost projects;
>this time my boss allowed me to spend as much as I want (oh well...)
>
>My question is: is there something ready-to-wear to perform the four
>functions that I need, or do I have to toy with half a dozen of different
>circuits (one to dial, one for the DTMF tones and so on?)
>The total length of the recorded messages is about 5 minutes; quality is
>not a must, so long as you can understand the messages.
>
>Thanks a lot for any reply, tip or hint.
>
>By the way, if you need help with the 8870 or the ISD1020 I'm here to help.
>
>Bye,
>
>Flavio Rizzardi
>design engineer
>
>
Morgan Olsson, MORGANS REGLERTEKNIK, Sweden, ph: +46 (0)414 70741; fax 70331
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