Re: DTMF dead?

Vladimir Vassilevsky <antispam_bogus@xxxxxxxxxxx> wrote:



Nico Coesel wrote:

I have an upcoming project in which I might want to use dtmf
transceiver chips as a simple means of communication. However, it
seems that dtmf transceiver chips are quite hard to get these days.
Even Digikey stocks none. Anyone knows a source that keeps making dtmf
transceivers for the years to come?

It is possible to encode and decode the DTMF with pretty much any
microcontroller. For example, you can do this:

http://www.abvolt.com/research/Multitone%20detect-IEEE.pdf

However, if the goal is the communication, I would rather implement a
PSK or FSK modem using a microcontroller. It would be much better and
even simpler then the DTMF.

I was hoping to use the analog front-end which is usually quite good
(reception downto at least -30dB). Its hard to beat that with a
microcontroller implementation (been there done that).

PSK / FSK is also an option. I just need something cheap and reliable
that will communicate over a 2 wire system carrying both communication
and power.

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