This is a common question, and our standard advice is to go to a university that offers both. Start out as one or the other or as an "undecided" engineering major. Take the intro classes for both and see what interests you. You may even do something like a mechatronics degree if your university offers it. Some people even stick around a little longer to do a double major. What is right for you will depend upon you, but you don't have to have it all figured out up front. The point is to move in a direction that seems right and adjust course as necessary.