HID-Data problem with one host (works with others)

[1.21Gigawatts]

I'm using the hid-data sample on a Mega644 (16MHz), and I've run into a problem. I've tested this with at least ten different computers, ranging from a netbook to an i7-980X. Everything works OK, except for computer, a 3.2GHz i5 running XP.

On the problem machine, my board enumerates OK and I can see it with USBDeview, but writing to it fails. I have set up the host software to retry writes, up to 100 times with a 100 mS delay between attempts, and this one machine just fails every time.

Any suggestions on how to troubleshoot this are welcome.

Thanks.

[Daid]

If it's just one machine it's most likely an electrical problem. Some machines are way more picky on the USB communication lines then others. Try a different USB cable, re-solder all your connections (I had one bad connection once, caused problems on only a single machine). Make sure you have a 100nF on the across the power/ground of the AVR.

[1.21Gigawatts]

OK, This is getting weirder and weirder.

I added the HID bootloader to my device, and now, even though the main program still fails on this one PC only, the bootloader works fine. That, I would think, pretty much eliminates any hardware problems.

So now what?

[Mike J.]

Hello 1.21Gigawatts,

connect your V-USB-Device to a USB-Hub (USB 1.1 or 2.0) this can solve a many problems with some crazy South-Bridges.