1 Jan
2010
1 Jan
'10
8:51 p.m.
On Jan 1, 2010, at 3:04 PM, Tom Uban wrote:
--
Dave McGuire
Port Charlotte, FL
While this doesn't have any classic content, it
may be interesting
to some.
I'm working on modifying a Heath/Zenith wireless doorbell to play
a sound effect other than the really bad "ding dong" or
"Westminster"
version of the same. The new sound effect will be the Cloister bell
from the Doctor Who series.
Patching into the doorbell circuitry to detect when it is playing
its builtin sample is relatively easy. Coming up with a simple method
of outputting my new sample is a bit trickier. As I recall, there were
some specialized ICs out a few years back which would do just this
sort of thing. I've also considered connecting a basic mp3 player.
Other suggestions?
The ISD series of chips from Winbond will do the trick nicely.
They store sound in what amount to analog EEPROM cells. I've
designed with them; they are easy to deal with and work very well.
Versions are available with pushbutton-compatible control signals,
I2C, and others. Some have "address" pins so you can have multiple
addressable messages.
They are more or less self-contained; they require very little
support circuitry. You can have a basic record/playback circuit up
and running in an hour or two.
Look at the ISD2560, for example.
-Dave