X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com Message-ID: <20120506172304.3670.qmail@stuge.se> Date: Sun, 6 May 2012 19:23:04 +0200 From: Peter Stuge To: geda-user AT delorie DOT com Subject: Re: [geda-user] 16 bit signed PCM .wav file into an EEPROM Mail-Followup-To: geda-user AT delorie DOT com References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Reply-To: geda-user AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-user AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk Rob Butts wrote: > Microchip 8 bit microcontroller with six IO pins .. > My dilemma: > 1. What is the best/easiest file type to convert the quack to. > 2. How to get the .wav file (or other file type) from my hard drive > into the eeprom. > 3. What type of cheap DAC chip to use (not familiar with them at all). Need much more information about requirements to give good advice. How cost and power sensitive is the final solution? What volume will you manufacture and how? Are you hand soldering or not? Are you comfortable with very small surface mount pitches? 16-bit .wav is probably much too high quality for the target system, and the file may also be in stereo so if you have just one speaker you could possibly reduce the .wav file size by 75%. 64kbyte EEPROMs are not so hard to find. Then, you have to produce the output. I assume that all six IO pins are not available for audio output. How many are available? Does the micro have a USART which is available, or will you have to bitbang everything? This may matter since especially some smaller PICs don't go too high up on the MIPS scale. For mp3 you could look at some of the numerous PIC+STA013 projects documented on the internet. They also include various DACs. For a more all-in-one solution you could replace the PIC completely and go for a fully open compressed format such as Ogg Vorbis or FLAC, using VS8053: http://www.vlsi.fi/en/products/vs8053.html Note that it is possible to add user code into the VS8053, and it includes the DAC, so it is truly a single chip solution. It's of course more expensive and power hungry than a PIC though. //Peter