I would like to ask some questions concerning microSD cards:
From the Raspberry Shake manual: “We strongly recommend against using consumer-grade TLC microSD cards with Raspberry Shake. Use commercial-grade (MLC) or industrial-grade (SLC) microSD cards instead.” The problem is that I am not finding any microSD card where the grade is mentioned by the manufacturer. Is there a way to know the grade of a microSD card based on other properties/specs?
Also from the manual: “Recommended size: 8 Gb (this is also the minimum size)”. Are there any disadvantages of using higher sizes on RS3D? Or is it just a recommendation on the minimum size?
Is there a limit on the maximum number of days for which the records are saved in RS3D?
Hello HoussamAlJama, and welcome to our community!
Thank you for contacting us about your queries. I will answer them one by one:
On this, you can find more details on MLC/SLC microSD cards here: https://documents.westerndigital.com/content/dam/doc-library/en_us/assets/public/western-digital/product/embedded-flash/product-brief/product-brief-western-digital-industrial-sd-microsd.pdf
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. We do not recommend going beyond 32GB and instead install an external USB storage (How to mount a USB to store the waveform archive) to save all your data.
No, the limit is configurable from the user interface of the RS3D itself. In the end, it will depend on the maximum storage capacity installed on the instrument, following this calculation (Commonly Asked Questions). As stated above, with a USB external storage, data capacity can be increased quite a lot.
Thank you very much, that was helpful!
Regarding the third item, it is shown in the link you sent that, for a RS3D, 30 days need 6 to 10.5 GB of storage. However, there is another file (“Specifications for: Raspberry Shake 3D”, https://manual.raspberryshake.org/_downloads/SpecificationsforRaspberryShake3D.pdf) where 8 GB are shown to support up to 110 days.
Which one of those should I follow?
You’re more than welcome; no problem at all.
Thank you for pointing this out, we will take care to update our documentation throughout all sites. To obtain the maximum storage capacity (and other useful data) per instrument, per SD card size, a general formula can be applied:
1. TMD = Total Mb / Day / Channel = 15Mb
2. TMI = Total Mb / Day / Instrument = Total Instrument Channels * (TMD)
3. TSD = Total SD Card Mb Available for Data = SD Card Size (from "df -h") - 4Gb (System Files)
4. Max Total Days Data Can be Saved = (TSD) / (TMI)
5. Total Mb Overall Saved to Disk = Total Days Data Saved (configured by user) * (TMI)
So, using the RS3D as example, with an 8GB microSD card installed:
1. TMD = 15Mb
2. TMI = 3 * 15Mb = 45Mb
3. TSD = 7.1Gb (from "df -h") - 4Gb = 3.1Gb
4. Max Days = 3.1Gb / 45Mb = 68 (rounding down)
5. Total Mb Saved = 68 * 45Mb = 3.06Gb
Thank you for your response.
I have another question regarding microSD cards:
After installing my first RS3D, I got a blinking red LED. Additionally, I got many gaps in the data stream (both online and offline). This is why I formatted the microSD card and installed the RS OS. I followed the instructions found here: Undervoltage - #5 by iannesbitt
However, the SD card reformatting tools mentioned in the steps (which I found in the “microSD burning” documentation, Best USB format tools | Pen drive / stick formatters for Windows - free download) did not neither on Windows nor at Ubuntu. I used another tool called “SD card formatter” (Download SD Card Formatter for Windows and Mac (UPDATED)) on Windows to format the card (FAT32). Then, I followed the steps of burning the OS into the card from the manual in Ubuntu. At the end, after a successful burning using Etcher, I got an “unallocated” partition in my card, called “Free space” (size = 4.7GB) (picture attached).
Accordingly, I decided not to put the card into my RS3D before verifying: Did I do anything wrong? Is it normal to get this “Free space” after installing the OS? Can that space be automatically allocated when I put the card in the RS3D?
Thank you again and sorry for the long and many questions!
The unallocated space partition is normal as you have just installed the OS but have not yet booted the Shake up with this new installation.
Once you do it, the Shake OS will automatically resize itself to adapt to the microSD card in use, naturally leaving other free space to store the data the Shake will record.
If the gaps in the stream reappear, or there is anything else that seems not to be working fine, please download the logs (instructions can be found here, if needed: Please read before posting!) and post them here.