Using a MicroSD Card
An SD card is a flash memory device that uses quantum tunneling effects to store information. Sort of like locking a piece of iron a secure glass box, and using a magnet to move it around to store information. The smallest version of the SD card available right now is the MicroSD format.
The Omega2+ comes with a MicroSD card slot, enabling you to greatly expand the storage capacity of the Omega without much added cost. The MicroSD card slot on the Omega2+ can be found at the bottom of the board inbetween the pins.
We’ll cover how to insert the SD card, how storage devices work in Linux, how to work with files on the card, and how to safely remove it without damaging your data.
Note: The Omega2+ supports MicroSD card on firmware builds b143 and higher. Always remember to upgrade to the latest firmware when working with SD cards!
Inserting a MicroSD Card
The MicroSD slot is spring loaded, and it will remain in place once it’s locked in. to properly seat it,
To insert the MicroSD card, you should firmly push the SD card into the slot until you hear and feel a click.
This is what it should look like once seated properly -
After you insert the card, you should make sure it’s mounted in the filesystem and accessible.
Occasionally, the spring mechanism may be already preloaded and your card will pop right back out if you let go. Simply pushed it back in until the click, and you should be all set.
If you’re running the latest firmware, the Omega should have automatically mounted the MicroSD card already.
Storage Devices and Linux
On a Linux device, a storage device needs to be mounted in order to access the data. Mounting a device maps its storage space to a directory on your device so that you may access it.
The Omega2 comes ready with an auto-mounting tool that will take care of that process for you!
The default mount location is
On firmware older than
v0.3.0, the default mount location was
mountdpackage controlled automatic mounting. Firmwares
v0.3.0and up use the
Accessing the MicroSD Card
Under normal circumstances, the SD card and any USB device you plugged in should be the only things that exist in the
/mnt directory. Thus you can check there with
ls /mnt/ to determine the name the Omega assigned the card. Running
ls /mnt gave us
mmcblk0p1 as the name of our MicroSD card.
Once mounted, it acts as a regular directory or folder in all ways, and any file that you stored in the card originally should be there! For us, it looked something like this:
root@Omega-1234:~# cd /mnt root@Omega-1234:/mnt# ls mmcblk0p1
p1in the name means partition number 1 of the MicroSD card, if you have partitioned your MicroSD, they should show up as
mmcblk0p2, and so on.
If you’d like to change where the MicroSD card is mounted on the filesystem, we’ve written a guide covering how to do so for both MicroSD cards and USB drives.
Safely Removing a MicroSD Card
To safely remove your SD card you should always unmount it first. This will eliminiate the possibility of the data being accessed while you physically remove it, which can corrupt the SD card’s data and filesystem.
umount command is used to unmount the storage.
umount <mount point>
From the above example:
unmount! We’ve made this mistake more than once!
Now that the card is no longer being used by the Omega, we can physically remove it without risking corruption.
The MicroSD card can now be safely removed.
Just push until it clicks.
Now you can pull it out of the slot - careful not to lose it!