SD card¶

The SD card (Secure Digital Card) is a widely used portable storage medium, featuring small size, large capacity, low power consumption, and ease of use. It is commonly used in mobile phones, cameras, embedded devices, and single-board computers to store system files, applications, and data. It is one of the most mainstream storage solutions in modern mobile and embedded devices.

Hardware Interface¶

The Quectel Pi M1/L1 smart controller board is equipped with a micro SD + Nano SIM combo card slot, supporting the SD 3.0 protocol.
Note: The upper slot is the micro SD slot, and the lower slot is the Nano SIM slot.

../../_images/image_NKbhbscINoGUjExRSWEcajH2n4b.webp

Function Usage¶

System Detection¶

After inserting the SD card, use the following command to check whether the system has detected the device:

fdisk -l

By comparing the output before and after inserting the SD card, you can see that the system has successfully detected the SD card:

../../_images/image_K9UTbYi2lodWmXxIKO2c3i22nOf.webp

Mount and Unmount¶

Check the mount path:

df -h

As shown below, the device is automatically mounted to /mnt/sdcard:

../../_images/image_AeDNbuApyowYDpx8WvFc6y55nvb.webp

List files in the mount directory:

ls /mnt/sdcard

Mount to another directory:

sudo mkdir -p /media/sdcard
sudo mount /dev/mmcblk1p1 /media/sdcard

Check the mount result:

ls /media/sdcard

Unmount when done:

sudo umount /media/sdcard

Tip: Unmount the SD card before removing it to prevent data corruption.

File Operations and Permissions¶

When a normal user accesses the SD card, permission issues may occur. Change the ownership of the mount point with the following commands:

sudo chown <username> /mnt/sdcard
sudo chmod 755 /mnt/sdcard

Replace <username> with your current login username. After that, you can read and write files normally in /mnt/sdcard.