I am trying to understand the pins on the header as I would like to get card detect enabled. I am not using the GHI SD Card board but a 9 pin board with CD. The 8 other pins [ Dat0-3, CMD, VDD, GND, CLK] hook up fine and the basic read write samples work (with a Thread.sleep(1) to enable the unmount without an exception).
What pin if any should I connect CD to?
I am struggling to understand IO4/PWM. The USBizi manual says that On power up, this pin is used to select the communication interface for GHI boot loader and debugging. So what purpose does it have for SD Cards?
Out of interest what is IO46* power enable signal for?
IO4 is the MODE pin. At boot time (before your app starts!) it’s checked to see what debugging to use. It doesn’t have any impact on your app when it’s running, and it doesn’t have any direct impact on the SD card. It can be used in your app as a PWM pin, as ain interrupt input pin, or as a general IO pin.
I’d suggest you use IO4 as your CD pin Unfortunately, you’ve got to implement the code for sensing CD yourself.
Power Enable must be a SD or MMC card specification / requirement, but i have no idea either what it is for or how it’s used.
If you look at the schematic of the Panda2 or the Domino then you will see that the Power Enable pin is used to turn the power to the SD card on and off. This is purely for power saving and isn’t required…
Card detect is just an IO, it is high when no card is inserted and low when it is inserted. IT can be connected to anything. We may have connected it some pin one board A but that doesn’t mean it will be on the same pin on board B. Did I answer your questions?
Unfortunately, you’ve got to implement the code for sensing CD yourself.