Why doesnt AVR-USB gets detected sometimes by the host

lpx · Post by **lpx** » Mon Oct 27, 2008 5:50 pm

Hi,

Sometimes the implementation of AVR-USB does not get recognized. Is there any reason for this?

If i plug it in in a Hub, it is different. It usually works better.

Any tips?

Thanks,

Nuno

Post by **christian** » Tue Nov 04, 2008 12:02 pm

Did you check the voltage level on D-? It should be between 3 and 3.6 V when no data is transferred. You need low power zener diodes on D+ and D- unless you use a 3.3 V voltage regulator for the AVR's supply.