====== Yakumo Hypersound Car ======

I bought this car mp3 (MP3-CD/MMC/SD/USB/radio) player during summer of 2005.
It was relatively cheap, and most importantly, it had a SD/MMC card slot.

Yakumo has a German-speaking support forum here:\\
 http://forum.yakumo.de/german/index.php?t=thread&frm_id=123&

This car radio was also sold in a near-identical version by Aldi-Sued in Germany under the name "Tevion ...???" but without a remote control.

It has the ability to record from radio/line in/CD/... and encode to MP3 in real-time. (Nice for recording from radio).

It appears that there's one bug, namely that the CD drive sometimes stops reacting. When this happens, it wont accept/eject/play CDs.
When this happens, pressing the reset button brings it back to life, but of course the radio station memory keys loose their information...

===== Whats Inside? =====

Here are some misc stuff I found out about the unit:
  * The Main Board uses a ST7 microcontroller: ST72F321. 
     * Datasheet here: http://www.st.com/stonline/books/pdf/docs/7599.pdf
     * Forum here: http://mcu.st.com/mcu/modules.php?mop=modload&name=Splatt_Forums&file=viewforum&forum=1
  * The USB/MMC/SD seems to be controlled by a board with
     * SST 39VF800A
       * "Multi Purpose Flash" memory
       * http://www.sst.com/products.xhtml/parallel_flash/39/x16/SST39VF800A
       * http://www.sst.com/downloads/datasheet/S71117.pdf
       * 512K x 16 (8MBit)
     * Samsung K4S161622H
       * http://www.samsung.com/Products/Semiconductor/DRAM/SDRAM/SDRAMcomponent/16Mbit/K4S161622H/K4S161622H.htm
       * Datasheet: http://www.samsung.com/Products/Semiconductor/DRAM/SDRAM/SDRAMcomponent/16Mbit/K4S161622H/ds_k4s161622h_rev15.pdf
       * 512K x 16Bit x 2 Banks SDRAM ==> 1Mx16
     * Telechips TCC720A
       * Appears to be a MP3 decoder chip, based on a ARM940T
       * http://www.telechips.com/product/product_mp3_tcc72x.htm
       * apparently, the datasheet is not publicly available
       * has an on-chip stereo DAC
       * can interface: IDE, USB, IrDA, SRAM, DRAM, Flash, ...
       * has a JTAG interface.
  * The interface board thats piggy-backed onto the board with the Flash/DRAM/TC720 has
       * a SD/MMC card slot
       * the USB connector
       * two voltage regulators:
         * a 7805 LDO voltage regulator
         * a SAC15x0  (x is not readable, but probably a 0)
           * Up&Down Multi Voltage Regulator
           * can deliver up to 1000mA
           * more info here: http://www.cosmodesign.com/english/analog/udmvreg.htm
       * and a WM8725 (WM8725GED) stereo audio DAC
         * http://www.wolfsonmicro.com/products/digital_audio/dacs/WM8725/
         * Datasheet: http://www.wolfsonmicro.com/uploads/documents/WM8725.pdf

  * The CD Drive takes up the most space, but can be removed quite easily with just four screws and one flat cable (24pin). It was made by Komec
      * http://www.komec.com.cn/eabout.htm
      * Seems to be a CDX-100 Series. (Although I can't exactly identify which one). http://www.komec.com.cn/eproduct.asp?classid=&Page=1
      * It uses a Toshiba TC94A14 chipset
        * http://www.semicon.toshiba.co.jp/openb2b/websearch/productDetails.jsp?partKey=TC94A14FA
        * Datasheet: http://www.alldatasheet.com/datasheet-pdf/pdf/TOSHIBA/TC94A14FA.html

===== Pictures =====

While taking it apart, I took lots of pictures: http://projects.varxec.net/images/yakumo/gal/yakumo_car_mp3_galleryidx.html \\
(I also put it back together, and it still works 8-) )

===== Where to Buy =====

Where to buy:

  * http://www.amazon.de/exec/obidos/ASIN/B0009MZ7P2/302-7243173-7480049
  * http://www.reichelt.de  OrderNo: YAK HYPERSOUND C