I am having the same issue with my used atmega168. I am working with one of Ocean Controls DC motor PID speed controllers and I would like to customize the application (which they allow but I have yet to get myself up to speed). I am using a usb avrisp on com 3. I’ve made several attempts and it will never enter program mode. The atmega168 was previously used and I am wondering if it is locked(protected) because of the programming that it contains from Ocean Controls. My board is the one created through the SFE tutorials (http://www.sparkfun.com/commerce/tutori … ials_id=93).
Is it possible that the chip is locked? I am very new to this.