Re: Need good quality Audio output through LPC21xx controller

On Sep 30, 6:56 pm, Vladimir Vassilevsky <antispam_bo...@xxxxxxxxxxx>
wrote:
angadd...@xxxxxxxxx wrote:
We are working on a project based on Vehicle tracking system.In one of
our module we are using audio(voice)  for Public transport  system.As
if for now we are using  filters and a power amplifer We are not able
to get good quality audio output with this setup.

Item used:
Lpc2132 with MMC card interface ,High pass filter+ Low pass filter+
Audio Amplifier+ Speaker

Requirement:

Good Voice quality annoucement system for Public transport System

With PWM at 32kHz carrier and 8bit quantization, you can get a
"telephone line" quality speech. It would be even better if you apply
the preemphasis and the noise shaping to the recorded signal. You can
gain somewhat more quality if you combine several PWM channels. However
if you need the "music" quality audio, you should use an external DAC.

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

What about DAC codec ??
It needs I2S interface which is not available with LPC21XX.
If anyone know how to convert SSP from microcontroller controller to
I2S format in software.
.