SD/MMC card

[ombrastein]

Hello all

Im working on a SD/mmc card reader for a MP3 player.
Im using a 18F452 and CCS PCH compiler

I have tried many difrent code interfaces, the last one beeing the mmcsd.c driver suplied with the latest PCH compiler.

It seems i am doing somthing hopelessly wrong.
My 18F452 is running on 3.3V (regulated by a LD1117)

i have 10k pullups on the DI and DO lines. Im using the standard pins on the hw module, and B5 for the CS signal.

I keep getting the same problem. The initsialisation rutines fail.

the mmcsd.c returns 0x80 wich means the CMD0 comand gives no response...


What could i possibly be doing wrong? THis seems straight forward...

Thx for any help provided. Im lost ...

[ombrastein]

Forgot to mention that i have conected Vcc, GND, DI, DO CLK and CS pins.

THe rest is left open and floating. Could that be my problem?

COM, WP, CD, PS and IRQ is left open

[Guest]

seems i had made a very silly mistake.

obiusly DI on the micro goes to DO on the MMC, and the DO on micro to DI on MMC, not DI <-> DI and DO <-> DO



Anyways... next step is to try and read a file of the MMC using the fat.c lib suplied with the CCS compiler...


Anyone tried to use this pice of code? Any experince to share would be most welcome...