USB Host mode: Memory Card Readers
 

I'm having trouble with a USB device when using USB Host mode (via usb_control).

I'm using the standard N810 USB lead with a gender-changer. I put the N810 into host mode and plug in a San Disk Cruzer Micro USB stick. A message pops up saying 'usb device not supported'. Despite this message, a few seconds later, the File Manager pops up and I can browse the contents of the device.

Now I try the same using a Multi-card reader (no name job), with a single San Disk 1G SD card plugged in. Again, I get 'usb device not supported', but this time, a few seconds later, I get a pop-up saying 'Unable to connect, no file system available'.

Checking on a PC, both devices work fine and are formatted with FAT.

I have also tried both devices with a powered Belkin USB hub and this time the memory reader was detected properly and reported itself as a USB2 Memory Reader.

Has anyone else had similar experiences with USB2 memory readers. Maybe my device is just too greedy?

Re: USB Host mode: Memory Card Readers
 

It needs more than 100mA, a powered hub is the only way to can use it.

Re: USB Host mode: Memory Card Readers
 

Virtually all memory card readers are in this category of requiring more power than the N800/N810 will put out, thus the powered hub approach. There have been reports of one or two "single" card readers that do seem to just squeeze by, but apparently they vary from manufacturer, type of reader, and just plain old luck. Do some searching around the forums here if you're looking for specific makes/models that others have confirmed to work.

Thanks!
-Rob