Re: Need good quality Audio output through LPC21xx controller [ LPC214x ? ]

angaddhot@xxxxxxxxx wrote:
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.

Hi!

Use LPC2141-LPC2148 instead (have USB, RTC...), possibly cheaper than LPC2132, and is much faster (interleaved flash...):

LPC2141, LPC2142, LPC2144, LPC2146, and LPC2148 device highlight:
http://www.standardics.nxp.com/products/lpc2000/lpc214x/~LPC2148/

LPC2148:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=568-1765-ND

LPC2141:
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=568-1761-ND

Example:
MP3/AAC player decoded in the ARM processor:
http://www.mikrocontroller.net/articles/ARM_MP3/AAC_Player

ARM7 LPC2148 mini board:
http://www.scienceprog.com/arm7-lpc2148-mini-board/
ARM7-Base development board for LPC2148:
http://www.scienceprog.com/arm7-base-development-board-for-lpc2148/
First LPC2148 ARM7 microcontroller test–led blink:
http://www.scienceprog.com/first-lpc2148-arm7-microcontroller-test-led-blink/
RTC example on ARM7 LPC2148 using WinARM:
http://www.scienceprog.com/rtc-example-on-arm7-lpc2148-using-winarm/

/Glenn
.

Relevant Pages

  • Re: Need good quality Audio output through LPC21xx controller
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  • Re: Need good quality Audio output through LPC21xx controller
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