Reply To: Portable Data storage memory cards

[deleted]

I’m not 100% clear on what you want your box to do, but I’ll try answering as much as I can along with posting some of my own views. 😉

For display options, currently I do not know of any.
However, it might be possible at a later point in time, because displays could be connected via Mini-PCIe or USB2.0 or USB3.0:
* Under the FAQ, GlobalScale writes: “There are USB touch-screens with Linux drivers, if anyone manages to operate it please share with us”.
* Mini-PCIe: This interface can be “broken out” to a single PCIe 2.0 x1 lane. It would be enough to drive a display for basic non-demanding graphics.
* Mini-PCIe: There are Mini-PCIe-to-HDMI interfaces available.
The above “possibilities” are currently not available to my knowledge – the hardware exists, the driver software is required in order to use the hardware.

Regarding SPI displays: Those SPI displays I know of, operate on 3.3V.
That’s way too much for the EspressoBIN; which could be damaged if you don’t know what you’re doing.
It’s likely better to see if you can find a touch-display that can be connected via USB2.0 (since you’re going to use USB3 for data transfers).

Regarding the ‘portable backup for CF and SD cards’, I am not completely sure what you mean.
Do you want to make a box, where you insert a SD-card or CF-card into a card reader and then copy the contents onto the harddisk ?
-If so, then yes Linux can do that already; it will require that you have a driver for the card-reader you want to use – unless it’s identifying itself as a mas-storage device just like a “SD/MMC-to-USB adapter” does.

Will you be possible to make your own “program” that makes it easy to copy cards to/from the SATA drive ?
-Yes. You can use the ‘cp’ command for this; so you can write a shell-script – it’s not even necessary to know the C programming language, bash/perl/python will do fine.

Now, if you do know how to design PCBs yourself, you could find a cheap SPI display on eBay, and design a PCB to hold a TFT touch-display, which communicate with the EspressoBIN through a voltage level converter. If you’re experienced, this will be a quick job, but if these are the first steps regarding electronics, it’s better to ask a company (such as … say … GlobalScale) to design a SPI-display board, but it might cost you some money. 😉

If you do not need a stand-alone box, you can connect a computer to the device via …
1: The microUSB-port (this will act like a serial port on the computer)
2: Via one of the GbE ports using SSH.

The quickest way for you to test if something like this would be possible, is to …
1: Get the EspressoBIN board if you don’t have it already.
2: Install Linux (for instance Armbian) on a micro-SD card.
3: Connect a computer to the micro-USB port and open a serial terminal.
4: Log in, issue an apt-get update followed by apt-get upgrade, then apt-get install nano ssh-server
5: issue a ‘lsblk >~/unplugged’ command
6: connect your card-reader to the USB3 port and insert a card.
7: wait a couple of seconds, then issue a ‘lsblk >~/plugged’ command
8: issue diff -U0 ~/unplugged ~/plugged

If there is a change (eg. the card is recognized), then the card-reader is already supported.
Try steps 5 .. 8 with both the CF card and the SD card.

If you don’t see any output at step 8, I believe you’d need a driver for that particular card reader.

Now as for power, batteries will do fine.
I recommend that you do not use a 3.5″ harddisk, but instead I recommend that you use a 2.5″ harddisk.
The reason is that the 2.5″ harddisk uses less power (Personally I like WD-RED, which uses only 0.2W in idle state and max 1.4W when reading or writing – note: that’s very little! WD Blue and WD Black also use little power).

If you use a 2.5″ harddisk, then you can use batteries easily. Just make sure your output from your batteries stays between 5.2V and 12.0V (not below 5.2V and not above 12.0V)

Let’s say you use a bunch of “1.5V AA” batteries; these are actually 1.2V, so you’d need at least 5 batteries to reach a voltage above 5.2V.
5 of those batteries in series will give you 6V.
-But they will be drained of power quickly.
To fix this, you can make several “strings” of batteries that you connect in parallel with the first one.
-Or simply purchase a stronger battery. 😉

What you do not want to experience, is that you’re writing to the harddisk, SD-card or CF-card while the battery is about to run out of power.
That can easily damage all your data on the drive or card you’re writing to.

If you want to use a SSD instead of a harddisk, then I think it’d use less power, since there’s no motor that has to spin up and no mechanical arm that needs to be moved, but SSD is expensive and you don’t get much space per buck. Another drawback regarding some SSDs are that they wear out quickly if you write to the same place many times. Newer SSDs might be a little more intelligent (but there’s no guarantee here unless the manufacturer says otherwise).

EspressoBIN is a real good choice if you want an affordable device that fully supports a true 6G SATA interface.