as someone that has taught at university, i have the following advice. Uni isnt about teaching you a subject, uni is about giving you the tools to learn a subject. if all you know is what has been taught, then you will know little.
uni has always meant to be about learning how to learn. this over the years has been lost. most uni's have etc classes etc and guest speakers who do lectures not in the schedule, go to these, read what you can, go to your lecturers and ask questions. Look at there personal pages, just about all will list there area of research etc on the uni website. if any are doing research that appeals to you, go talk to them, most will allow you to take part or watch. be proactive.
dont expect the knowledge to be placed inside your head, go put it there.
most uni's allow the use of labs at lunchtime etc if you ask nice.
stand up in a lecture at least twice and ask a sensible well thought out question, the reason is, in order to do that first you have to read about whatever the lecture is about first
i.e do your homework before each lecture so you know something about the topic first
my area isbiology but i cant see electronics being different in this respect