We're two partners, he's technical and I'm the business guy. A couple of months ago, I made sure those lines stayed pretty well delineated. Product was his issue; marketing, sales, and fundraising were mine.
The problem was, with no product in the field yet, my job was a lot easier, and I found myself with less and less to do. As unforeseen problems arose on the product side, I made the leap, and added a new hat to the pile - engineer (well, pretending to be one).
It was the right call. Not only is product development moving faster, but my understanding of the process and, more importantly, our product has increased tenfold.
The job of the CEO in an early hardware startup is not to raise money and present the business case; it's to do whatever it takes. If you have a team of engineers, that can mean just focusing on more traditional "CEO hats." Yet, if you're lean and bootstrapping, like we are, there is no role outside of your job description.