microSD card topics

microSD cards are fragile and fickle. The microSD card is the weak link in the Raspberry Pi computer and you should expect to have to replace it from time-to-time. But do not fret! Replacing the SD cards is simple.

How to get the most out of your microSD card

Since all of the software that makes Raspberry Shakes run lives on the microSD card, it is worth protecting them.

The life of your microSD card will be a short one unless you take some easy steps to protect it including:

  • If you plan to move your Raspberry Shake from one location to another, or shut her down for any reason, always do so from the web front-end. Never just pull the plug on her. Doing so will damage the microSD card and may even render it dead.
  • We recommend pairing your Raspberry Shake with a small UPS backup power supply. UPS’s that have Ethernet protection are the best. Doing this will protect your Raspberry Shake from spikes and other inconsistencies in the power supply (something less important for highly developed countries) but, more importantly, it will help the Raspberry Shake bridge short- to medium-term power outages, dramatically extending the life of the microSD card.

How do I know that my microSD card is corrupt and needs to be replaced?

If either:

  1. The green ACT LED on the Raspberry Pi computer board does not occassionally blink; or
  2. The same LED is permanently lit.

Then your microSD card needs to be replaced.

Details:

If you suspect that your microSD card has died, you can usually tell by checking the LEDs next to the power connector on the Raspberry Pi Computer. There should be a red one labeled PWR. You can ignore this, it only tells you that the unit is powered on. Right next to it is another green LED labelled ACT. This should blink every now and again. This blinks when there is activity on the microSD card which can only happen if the operating system booted successfully. If you never see this green LED blink or it is permanently lit up, then the microSD card likely needs to be replaced.

How to burn the raspishake image to your microSD card

Note

All models of Raspberry Shake, including the RS1D, RS3D, RS4D, RBOOM, RS&BOOM and RJAM use the same software.

You can download the microSD card image here.

Recommended size: 8 Gb (this is also the minimum size)

Follow these steps:

  1. Download the image from the link above

  2. Unzip it. One of our Windows users recommends using 7-Zip (http://www.7-zip.org/) to unzip the file.

  3. Insert an 8 Gb microSD card into your computer (most computers will require an microSD-to-SD card adapter to accomplish this)

    Note

    Linux users can use:

    $ sudo dmesg -T
    

    to look for the last sdX devices that have been recognized (e.g., sdb [but not sdb2, for example]), confirm the correct microSD and see the amount of space available

  4. Burn it to a microSD card (this can take a while …).

    For Linux Users use dd command:

    $ sudo dd if=raspberryshakeSD.img of=/dev/sdX
    

    For example,

    $ sudo dd if=/home/branden/Desktop/raspberryshakeSD.img of=/dev/sdb
    $ 15523840+0 records in
    $ 15523840+0 records out
    $ 7948206080 bytes (7.9 GB) copied, 4072.25 s, 2.0 MB/s
    

    For Windows Users download Wind32Diskimager here.

  5. When the process of burning your microSD card has finished, unplug it from your computer and, if your are on Linux, replug it into your computer. Now proceed to confirm that the partitions are mounted correctly by opening and exploring the file content as if it was a conventional microSD memory card (it will appear as “boot” and as “7,9 GB Volume”). In Windows this is not possible because Windows cannot recognize Linux-formated partitions and that is exactly what this is. If the mount is correct and no errores are seen using “sudo dmesg -T”, then your microSD card is ready to go.

  6. Unplug the microSD card from your computer and plug it into your Raspberry Pi

  7. (re)Assemble your Raspberry Shake and power the unit up

  8. If you are replacing the microSD card on a Raspberry Shake that was previously sharing data with the Raspberry Shake Community server, you will have to open the web config and reconfigure the unit.

  9. (OPTIONAL, RECOMMENDED): The image will have a size of ~4 Gb. We recommend resizing this to fill up the entire space provided on your microSD card. After ssh-ing into your Raspberry Shake (How to access your Raspberry Shake’s computer via ssh), run:

    $ sudo raspi-config
    

after starting raspi-config, navigate to ‘Advanced Options’, then select ‘Expand Filesystem’

Now reboot and you are done:

$ sudo reboot

A special note for users who plan to use the Raspberry Shake as a stand-alone datalogger

We recommend saving the continuous waveform data to an industrial USB. See here for details: How to mount a USB to store the waveform archive

microSD card Facts

More memory and reliability do not always go together when it comes to SD cards.

There are 3 kinds of SD cards, in order of robustness and price:

  1. Consumer grade:
  • highest capacity and lowest cost
  • NAND Type: Triple-level cells (TLC)
  • Geometry: 3 bit/ memory cell (this means that TLC cards can be larger in size than MLC & SLC cards. Anything over 8 Gb is definitely TLC.)
  • Write cycles: 2,000 - 3,000
  • The higher the storage capacity, the lower the life of the SD card because the way they cram more space onto these little microSD cards compromises their ability to recover from corrupt memory footprints
  1. Commercial Grade:
  • NAND Type: Mult-level cells (MLC)
  • Geometry: 2 bit/ memory cell
  • Write cycles: 100,000
  1. Industrial Grade:
  • NAND Type: Single-level cells (SLC)
  • Geometry: 1 bit/ memory cell
  • Write cycles: 2 million

To find out more about microSD card technologies, we recommend: