Hey guys,
I'm intergrating a SD-card module on my own PCB to connect to my Arduino GIGA R1. Does the schematic look good to you guys?
Normally speaking pin 2 is used as CS, and pin 9 is left unconnected.
I have additional 10K pulkups on pins 1, 2, 3, 5 & 7
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Okay, but why the pullup resistors, to keep the signal high or low?
The datasheet describes this for the pinout:
Okay man, your right about the pinout, does the CS-pin need any resistors? or can I just connect it right up to it?
You can connect it right to it, but i use a pullup to make sure that it doesn't go LOW during Boot.
Basically to keep them HIGH. I just copied whatever circuit i found on a SD-card unit, got that to work, just kept what was there.
Remember that in theory these SPI lines can be fed to multiple devices. When selected by its CS, a device pulls the lines low to use them, but never tries to drive them high. The pullup resistors are what takes them high when they are idle.
I believe pin 2 (CS) already has a pullup resistor inside the SD card, so you probably don't need one there. But the other three should have pullups somewhere. 4.7K to 10K are typical values.
Better test everything before you send of the gerbers for production.
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