Lutron Electronics Software Developer Intern interview questions

The interviewer was really nice and guided my through the problem when I got stucked. I didn't feel like I can pass, but I recieved the invitation of HR call. But just several days before the call, they called me and said they have already fill the spots. Soooo sad!

It was a video interview. The interviewer asked the questions and sketch the relevent diagram on a white board. I was instructed to use the white paper in front of me to answer the questions. Multiple brain teasers and electrical questions were asked.