68HC1 | 812A4 | 9S12DP256 | Bootloader | CodeWarrior | D60A | Debugger | DP256 | ECT | EEPROM | EVB | Flash | HC1 | HCS12 | I2C | IAR | ICC1 | Interrupts | LCD | M68KIT912DP256 | MC9S12DP256 | MC9S12DP256B | Metrowerks | Motor | MSCAN | Multilink | PLL | Quadrature | SDI | SPI | Transceiver | XFC

Hi everyone,

i=B4m just starting develop a datalogger that store the data in a SD card.
I=B4ve read that the all SD card pins must be link to a external pullups ev=
en
the unused data pins. I would like to know why it should be like that?

If someone have any documentation or examples that could help me in this
project would be great.

Thanks a lot in advance,

regards

--=20
Leonardo Rosa Lopes
Engenharia de Controle e Automacao - UFSC
Contato:
+55 47 9989-7129
+55 47 3801-4408
http://lrlopes.googlepages.com/leonardorosalopes
[Non-text portions of this message have been removed]
------------------------------------



(You need to be a member of 68hc12 -- send a blank email to 68hc12-subscribe@yahoogroups.com )

First, you should refer this question to the SD spec which you should
have. It can be downloaded for free.

If you are using the serial interface, you must pull up the data out
pin, because until the card is initialized this will float, and you
could end up clocking in 0s when you were expecting 1s.

Have you checked into dosonchip? Getting a file system debugged is
quite time consuming.

------------------------------------



(You need to be a member of 68hc12 -- send a blank email to 68hc12-subscribe@yahoogroups.com )