Hey everyone,

This might be a very simple question but I'm pretty stuck. Googling around has confused me more. So I'll explain how I plan on connecting this and maybe get a bit of insight from everyone here.

Here's the relevant links:

Molex 5031821853:

1) Datasheet

2) Drawing

So on the drawing it shows the 8 pins and two additional pins, namely the switch and detect term.

So I'd connect(operating in 4 pin SDIO):

Data2 & DAT1 & DAT3 & DAT 0: to GPIO pins for data transfer

CMD: to GPIO pin configured for CMD

CLK: to GPIO pin configured for CLK

Now comes the weird parts: On page 2 of the drawing, It has a detect term, With in brackets (Ground) so I plainly assume this means connect it to ground, it has another switch term, which I assume tells the system when an SD card is in the connector?

Finally Vss I'm assuming is ground and Vdd is 3.3V as it only states the maximum on the datasheet(i.e. 10V AC (RMS)/DC)

Also do I connect these directly to my MCU, I've seen people operate these with pullup resistors as such. Is this necessary?

Thanks in advance for any help or any links to nudge me into the right direction I've done research just found a lot of ambiguity.

 

Also do I connect these directly to my MCU .... Is this necessary?

What is the part number of your MCU ?

 

What is the part number of your MCU ?

Nucleo F722ZE

 

This is board's name.
So did you check what the datasheet of the MCU says about mmc serial interfeace, if any ?

 

The SD specs don't require pullup resistors. Most engineers add them to unused inputs only, I do too.

 

This is board's name.
So did you check what the datasheet of the MCU says about mmc serial interfeace, if any ?

The datasheet only mentions that it has one(stm32f722ze) and the dev board specifies specific pins that can be used for each of the 8 pin connections coming from the device(except the switch and detect terms). It has has a GPIO for detecting if a SD card has been inserted(which I think is the switch term), although on coupling the SD card or how the SD card pins should be mounted nothing much is said on either the Molex or STM site

 

The SD specs don't require pullup resistors. Most engineers add them to unused inputs only, I do too.

Great,thank you. I'll connect them directly to the mcu then

 

Here you can find the board schematics also and refer to ST's design.
Try to check yourself the MMC specifications & ST32F7 TRM.

 

Here you can find the board schematics also and refer to ST's design.
Try to check yourself the MMC specifications & ST32F7 TRM.

I've read through the reference manual, etc. I've been working with this board for a while, I also know which pins to couple to the board. It's more on the memory card side, I have no idea how the switch and detect should be handled..