Objective Development Forums

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.

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.

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?

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.