Single interview with two engineers running through a list of behavioral interview questions. Do not walk in unprepared for a STAR technique behavioral interview, they are bad enough even if you are prepared. No contact after the interview until 3-4 weeks later when an offer was extended. Not sure if they worked though a list of other candidates that declined or if they just work at the pace of a large corporation.
I brought a collection of hardware projects and schematics to my interviews. They provided excellent aid in answering the STAR questions. They also asked minor technical questions about the parts/layout I used to make sure I had some idea of what I was doing. Things like baud rates of the various data lines I used (SPI, I2C, UART), how much I trust datasheets, why I chose particular parts, and why I didn't use some alternate technology (resistive touch sense instead of capacitive touch sense).
I think the overarching goal of the interview was to get a sense of my problem solving methodology and whether or not I understood the basic trade-offs one deals with in engineering.