You have asked a quite a vague question and so by necessity the answer will have to be vague as well.
First, I suggest you do something that is well within your abilities to accomplish, but not so easy you don’t learn anything in the process. I believe a project for an engineering degree is usually expected to take two terms, involve some theoretical discussion and design, and then the practical of actually implementing the design, testing the results to prove or disprove the the thesis. This is usually “presented” to peers and examiners, with a Q&A session. Not as rigorous as a graduate thesis, but generally the same process.
Your supervisor will probably give you a list of several suggestions. You might discuss them – the supervisor will know what you can and can’t accomplish – and recommend something appropriate. Typically, they are sub-sections or practical implementations of some research he/she is working on, or pet ideas the supervisor or one of his colleagues has.
Discuss your super’s suggestions with them. Don’t be afraid to say, that’s quite theoretical for me, or too math heavy, or to much physical build, that you want something more practical or more theoretical. It will work out.