Matrix user forums

My project

MCU : 18F4550
Micro SD: Sandisk 512MB FAT16

My sd card design like this , except code protect and WP pins and mcu and sd card supply 3.3v

Init_FAT() return 254 0xFE - No Response Error.

mesurements with digital ossiloscope, logik analyzer seems be ok. My ossiloscope, LA is Owon MSO7102T

What is wrong?

Hello,

Hm, have you had the card working with another system eg E-blocks or are you trying it for the first time.

I would suggest that you maybe try some other cards or try and reduce the SPI clock speed for the FAT component. There are already a few topics on the forum regarding how to do this depending on which version of Flowcode your using.

I am currently working on the FAT component in my spare time to try and improve the functionality and allow the newer uSD and SDHC type cards to work. This may be some time until completion but I will let everyone know once I am done.

Let me know how you get on.

Hi,

Can you verifie if SDO and SDI is not inverted.

DI SDcard -> SPI MOSI
DO SDcard -> SPI MISO

If your UC power is 5V you must used Buffer between UC and SDcard


Source: http://fx.damasgate.com/accessing-flash-memory-cards/


Even with others SDcard hardware there is no problem but you must used SDcard no SDHC and < 2GO.


Nicolas.

Beta SD FAT component for v5 topic has been moved here http://www.matrixmultimedia.com/mmforum ... 46&t=10989