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SDHC card MISO Remains Low

Question asked by David Wright on Sep 16, 2011
Latest reply on Sep 19, 2011 by David Wright



I'm having an issue communicating with my SDHC card.  I should mention that I have communicated with this card before with the same code on a slightly older version of the circuit. 


The mcf51 is communicating with the card via SPI via potential dividers on CS, MOSI and SCK as the micro is running at 5V to fulfill several other requirements.  The MISO line is put through a hex inverter to buffer the signal up to 5V.


I have not connected any pullup resistors anywhere, but I assumed that it wasn't necessary given that first prototype I made worked without them with this same card.


Essentially I get no response from the card.  The MISO line remains Low all the time.  Can anyone suggest a potential reason for this?


Thanks in advance

Dave Wright