27/12/2013
There are so many devices available
which can record and playback voice.
Most of the digital devices like mobile
phones can use the SD card to record the
voice
signals
and
playback.
This
project
demonstrates
how to
record voice signals on a micro SD card
and play it back using the GR SAKURA
board. Voice signals are continuous
analog signals and the digital devices like
microcontrollers cannot handle the
continuous analog signals. Most of the
microcontrollers have an ADC module
which can do analog to digital
conversion.
The microcontroller uses sampling
technique to convert the continuous
analog signals to discrete digital
equivalent samples. While recording the
voice, the GR SAKURA board samples the
voice signals and writes the sampled
values to a file at the sampling time
itself. The same file is opened again and
reads the values at the same frequency
at which they are sampled.