Has anyone used the Futurlec SD/MMC Mini Board http://www.futurlec.com/Mini_SC.shtml with an Arduino...? Could I ask how you wired the two together and which library you used to read/write to the card?
The pins available are:
Sorry - very basic question - thanks.
Yes, I used it with a 3.3v CortexM3.
For 5v Arduino you need to drop the voltages of the 3 input lines, sclk, datain, cs. DataOut is fine. Wire this device up to the SPI port.
i.e. you need to connect:
Vcc, Gnd, Sclk, MISO, MOSI, CS of the arduino SPI to the card.
Also I don't think you need the pullups enabled either (arduino internals are set).
Heres the pin mapping : http://www.interfacebus.com/Secure_Digital_Card_Pinout.html
Pins8-9 are NC.
Heres a short article on dropping the voltage from 5 to 3.3:
I used SDuFat library to start but its very limited and quite painful(empty file of desired size has to pre-exist on card, etc).
I then found Fat16 library. Its bigger, but easier to use, lets you open files from scratch, etc. More like a normal file lib. However, this lib does not like resistor voltage dividers, theres a note about setting the spi bus speed lower. I backed up and ordered a few 74HC4050N line buffer chips, and these work great. Instructions on using a line buffer are in Fat16 help files.
BTW, the best SD/MMC board I've found for 5V systems is from Gravitech:
On-board 3.3 regulator and a "real" level shifter (74LCx245).
Real easy to use.
Thanks for the replies folks, I will give it a whirl.... much appreciated... I didn't even know about the volatge issue !!