Unable to read SD card (RAMPS 1.4+Reprapdiscount Full Graphic LCD)
For some reason, the my printer is unable to read files from an SD card. I have tried different cards with different formats, with files in binary and regular g-code. The only change I have made to the firmware in relation to the SD card was inverting the SD detect pin signal. When a card is inserted, it shows that an SD card is inserted with a message, and the menu entry becomes available, but upon selecting it, there is nothing to be found.