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AVR-doper

Posted: Fri Jun 27, 2008 8:55 am
by sidra
I bhuilt AVR-Doper(Robotron) PCB but my PC can't recognize them.Simply
I have a massage thet unregonizable hardware is present and this hardware work's not properly. What can be the problem?

Posted: Fri Jul 18, 2008 6:54 pm
by zacharius
have the same

Posted: Sat Jul 26, 2008 9:47 pm
by Guest
This means that USB hub and OS recognized the pull-up resistor but OS did not succeed in obtaining device's device descriptor. You can verify that by removing the CPU or by keeping it in reset and then pluging it in.

Posted: Tue Jul 29, 2008 5:40 pm
by christian
The most likely cause for this is a voltage level problem on D+ or D-. Please check the idle voltage on D- and ensure it's above 3 V and below 3.6 V.

Other things to try: Different host, insert USB 2.0 hub, swap USB cables etc. If one of these helps, a voltage level problem is very likely.

Re: AVR-doper

Posted: Mon Mar 12, 2012 5:29 am
by brotherhood
I have build the doper pcb,after pluging in it wasn´t recognized
After change the usb cable it was,and xp tells a new Hardware was found and can be used.but after a few seconds a pop up tells unrecognized Harware
same thing on other PC what can Happen about it?