Using with Raspberry Pi 4 #
Due to changes in the Raspberry Pi 4, in particular the way SD cards are read, because of this some additional steps need to be taken to get the Dual SD Card Expansion adapter to work correctly. This involves the following changes.
1. Make a backup of /boot/cmdline.txt sudo cp /boot/cmdline.txt /boot/cmdline.txt.bak 2. Edit the cmdline.txt file sudo nano /boot/cmdline.txt #Find the following word: root=PARTUUID=xxxxxxxx-xx #Note: The x's are placeholders, and will actually appear as letters and numbers. #Replace the word we just found (root=PARTUUID=xxxxxxxx-xx) with: root=/dev/mmcblk0p2 #Note: Make sure it is still in a single line, like it was originally. 3. At the end of /boot/cmdline.txt add: sdhci.debug_quirks2=4 #Ensure to keep all on one line. #Note: Adding sdhci.debug_quirks2=4 disables '1.8V' mode for the SD card, allowing UHD SD cards to be used at lower speeds.
Note: as further Raspberry Pi boards are developed, this will likely work on future releases.
Note: Maximum SD Card size is 32GB for use with this adapter.
