I always seemed to get a clash between the device select signal (SS) on my SD/microSD card reader and some other Arduino hardware I was trying to run with it. To get around this I decided to make a dedicated SD card shield with a jumper selectable SS signal.
SS signal clashes are now a thing of the past!
- +5V and GND. The device has an on board voltage level shifter to the 3.3V it needs to the SD card.
- MISO, SCK and MOSI. SPI pins that are connected to pins 12, 11 and 13 on my Arduino Uno.
- SS. The device selection signal, which I have connected to a jumper strip that allows connection to any of pins 2 to 10. The selected SS pin is passed to the SD library begin() method.
The resulting shield (shown below), is still thin enough to have another shield stacked on top, and the SD card can be removed from the side without unplugging the shield.