Hi, I'm trying to communicate with a SD card on MCI bus. I've implemented the structure of software released by NXP site (LPC23xx_24xxSampleSoftware.r5) to build my commands. When I send a comand to the card I've controlled the signals with my oscilloscope and I find them correct but the card doesn't answer. Have you got any suggestion to me? Have you got any simple piece of software that configure the card and send a command correctly? The amazing aspect for me is that the electrical signals are correct, so I don't know what to do to solve this problem...
Thanks and bye
Demis
Sure! I've configured the peripherals at 320 kHz (< 400 kHz as stated in SD card specifications for identification card mode) and I've controlled each bit with the oscilloscope. All seems right but the card doesn't answer!!! Specifically, first I send CMD0 (GO_IDLE_STATE) for which no response is required (therefore from a theorical point of view I don't know if it is received and interpreted correctly by the card...). Then I send CMD55 before sending ACMD41 but the card dosen't answer to CMD55 command (as required by specification) and I don't know why because there is no way to know the status of the card if it doesn't send any response! The fun aspect of the problem is that when I began to test my software the card answered correctly to the whole identification sequence for some times! Then it stopped answering till now and I don't know why...