Re: Speech output from a microcontroller



Pertti Kellomäki wrote:
I am looking into generating speech output from
a small datalogger (approximately match box size).
Any advice on how to go about it? There will be a
memory card and the words come from a small fixed set,
so storage is not a problem.

Way back there was a speech synthesizer for the RCA1802
that only used a single digital output pin, but the
sound quality was really not very good. What I'm looking
for is something similar, but with a bit higher quality.

I'm planning to use one of ATMega devices, though that
probably does not make much difference.

The ATMega PWM output at 32kHz sample rate will produce the speech of the reasonably good quality. Especially if you will employ the preemphasis and the noise shaping. The waveforms can be stored in the external flash as is; there is not much sense in using an audio compression.

Vladimir Vassilevsky
DSP and Mixed Signal Design Consultant
http://www.abvolt.com

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