dding a USB thumb drive reader to electronics (rather than SD card)

Gang!

I'm running RAMPS 1.4 with an SD reader. I would like to be able to run g-code off a USB thumb drive rather than an SD CARD. Can the regular USB port on the Mega be used to read via the USB drive?

I saw a module called:

CH375B Module USB SPI interface Communication U-DISK Read Write For MCU DSP MPU

[www.ebay.com]

Do I even need this?

Any Thoughts

Thanks

Max

The simple answer is no. To read a USB drive, you need a Host port, and the AVR has only a Device port.

OK, in theory you could build an external USB host to SPI bridge or similar, and I think there may even be shields to do things like that, but it is pretty unwieldy.

A lot of bigger micros have a combined device/host port (OTG) which could read a USB flash drive, with the right firmware. The Due has an OTG port for example.

Hopefully as we move towards ARM chips then it will be easier to support USB devices.

I was looking at hacking on a VDrive1-PCB (now superseded with vdrive2)

Its just a SPI or UART device that take simple serial commands.

To me it looks very doable, but the firmware was beyond me...

Dust Wrote:
-------------------------------------------------------
> I was looking at hacking on a
> [url=http://www.ftdichip.com/Products/Modules/Appl
> icationModules.htm#VDrive2]VDrive1-PCB[/url] (now
> superseded with vdrive2)
>
> Its just a SPI or UART device that take simple
> serial commands.
>
> To me it looks very doable, but the firmware was
> beyond me...

Hey, good find! That is just the type device I was thinking of. I knew FTDI do some good stuff, I didn't realise they did that. I probably should, since I have actually got one of their USB host dev boards I had forgotten about

I will order a Vdrive2, and have a play with it. The VNC2 chip it is based is only a few pounds, I think I can put that onto to a small board and have it plug into a suitable connector.

There are very affordable adapters to make a USB thumb drive with an micro or non-micro SD card. Search for "USB card reader". This would solve the problem on the PC side, no software, firmware or electronics modifications required. Just one example of many:

[dx.com]

---

Generation 7 Electronics	Teacup Firmware	RepRap DIY