How about a digital audio shield for FRDM-KL46/K20?

kai_liu — Thu, 31 Oct 2013 08:51:32 GMT

FRDM boards are great. However they follow Arduino layout and IO oriented. Maybe we should have some fun on it.

I found I2S port is available on FRDM-KL26Z and FRDM-K20. So I will like to propose to design an audio shield for them.

Basic feature:

microSD card

I2S output (interface to low cost UDA1330 DAC)

on board amplifier for headphone or small loudspeaker.

FRDM will use SPI to microSD card, use I2S as output

Arduino and Maple will use multiplex SPI as I2S, so microSD card is useless.

Basically it works a playback device only.

Advanced feature:

USB host for MSD

I2S input (interface to UDA1341 codec, a legacy silicon since MiniDisk age)

on board amps for headphone and microphone

I want to know your feedback on this idea. The poll is https://community.freescale.com/polls/1184

With reference documents, It can playback wav file with simple driver, acts as USB sound card.

Codec is much useful in digital audio, with proper firmware, it can work as a guitar mixer box, it requires more DSP processing power although.

However it will take more efforts for a complete MP3 decoding. So community co-operation and open source is important.

References:

http://cache.freescale.com/files/32bit/doc/app_note/AN4800.pdf

http://cache.freescale.com/files/microcontrollers/doc/app_note/AN4520.pdf

Re: How about a digital audio shield for FRDM-KL46/K20?

kai_liu — Fri, 01 Nov 2013 01:45:12 GMT

FRDM-KL46Z/K20D50 have different layout for I2S interface. KL46Z have a dedicated header for I2S, and K20 have not. In order to keep Arduino compatible, the shield has to support emulated I2S port with 2 SPI buses.

And 5V/3V converter is required as well.

Allan K Liu

Kinetis MicrocontrollersのトピックHow about a digital audio shield for FRDM-KL46/K20?

How about a digital audio shield for FRDM-KL46/K20?

Re: How about a digital audio shield for FRDM-KL46/K20?