Steve Church

MC9s08JM60 and SD card interface

Discussion created by Steve Church on Aug 22, 2009
Latest reply on Aug 25, 2009 by Steve Church

Hi,

I'm trying to put together a voice recorder/playback system using an SD card and a bought in FAT16/FAT32 driver from Embedded.com. I am using the SPI interface. I am finding that different cards behave differently under similar conditions, with most of them failing the initialise phase. I am getting responses from the card indicating illegal commands but I can see data in the correct places. Other times I get a response from the card which has been clocked out at the wrong time (e.g 2 clock pulses late). This all seems to point to clocking problems but I am running at about 1MHz after the initial 400kHz stage. I have turned on/off the slew rate limiting. I have tried using the high drive capability on the SPI pins, and combinations of both. Has anyone had any similar problems. At present I have a hand wired board but with very short ( < 1cm) wires to the SD card. I have a pcb on it's way but am running out of ideasif that doesn't sort it.

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