Hi all, I recently purchased a MicroSD card slot and some 23k256 chips. I need the extra memory as a buffer for files. Anyway, I wrote a small driver for the 23k256 (which has a 180 ohm resistor on the SI and SO lines) which works perfectly on its own. However, when the MicroSD slot module (which is a catalex one) is introduced, the SRAM module fails to read back the correct value, it just reads a flat 0xFF for every address read (the driver does a memory check by writing the current address and reading it back for the first byte of memory).
I have 3 wires coming from the SPI pins on the Arduino UNO (13, 12, and 11) which then get split with one of each going to each module. When ground is disconnected from the SD card, the memory begins to read correctly.
I’m sort of at a loss at to what the problem could be, so any help would be much appreciated (I’m a bit of a wiring noob, software is my strong point )