Special USB On-The-Go Copier?

[[email protected]]

Hi everyone,

I have been trying to find a USB OTG copier that will fit my needs.

I'm looking for a USB standalone device (no PC, hence the OTG) that
plugs in between a datalogger and a USB flash drive, but in a way that
the bridging device is invisible to the datalogger. That is, the
datalogger should only see the one USB drive.

However, I'm wanting to be able to make a copy of the USB drive to a
secondary USB drive - which would allow me to sneak a peek at the data
before the datalogging process is complete. (My application will run
up to 100+ hours but I might want to look at it every 12 hours to see
if its done if I can.) This should be done without interfering with
any data written to the main drive.

I suspect such a device could be made, but was wondering if anyone had
come across such a device?

Jim.

 

[Iwo Mergler]

Hi everyone,

I have been trying to find a USB OTG copier that will fit my needs.

I'm looking for a USB standalone device (no PC, hence the OTG) that
plugs in between a datalogger and a USB flash drive, but in a way that
the bridging device is invisible to the datalogger. That is, the
datalogger should only see the one USB drive.

However, I'm wanting to be able to make a copy of the USB drive to a
secondary USB drive - which would allow me to sneak a peek at the data
before the datalogging process is complete. (My application will run
up to 100+ hours but I might want to look at it every 12 hours to see
if its done if I can.) This should be done without interfering with
any data written to the main drive.

I suspect such a device could be made, but was wondering if anyone had
come across such a device?

Jim.

Hi Jim,

OTG is not what you're looking for. OTG refers to a single USB port
to switch between host or device mode.

There are two ways to achieve what you want. One, as you already
suspected, is a computer with a host and a device port each. You
could attach the flash drive and then export the file system via
the USB device port as mass storage - Linux can do this easily.

This is not necessarily a PC. USB device controllers for PCs are
exceedingly rare. There are microcontrollers around which can do
this. If you find a device with separate host and device ports
(or one of them and an OTG port) you can do it.

This system, for instance:

http://www.linuxdevices.com/news/NS7539700316.html

With a little Linux shell scripting, you could set it up to be a mass
storage device with as many mirrored flash drives you like. Conceptually,
it's a RAID array.

The other options is to tap into the communication between the logger
and the flash drive directly. This is called a USB sniffer - quite
expensive to build or buy.

Kind regards,

Iwo

 

[linnix]

I have been trying to find a USB OTG copier that will fit my needs.

...
OTG is not what you're looking for. OTG refers to a single USB port
to switch between host or device mode.
...
There are microcontrollers around which can do this.

For example, AT90USB1287 (one OTG port).

If you find a device with separate host and device ports
(or one of them and an OTG port) you can do it.

You can use a pair of them: AT90USB82 (USB device) and AT90USB1287
(USB host). They can communicate with serial or spi, etc.

 

[Jasen Betts]

Hi everyone,

I have been trying to find a USB OTG copier that will fit my needs.

I'm looking for a USB standalone device (no PC, hence the OTG) that
plugs in between a datalogger and a USB flash drive, but in a way that
the bridging device is invisible to the datalogger. That is, the
datalogger should only see the one USB drive.

such exist and unless you want to design one (and probably even then)
you're asking in the wrong newsgroup... try a general computing group.

Bye.
Jasen