"@ Ying Hong 
I left ERAU before the team integrated the wii sensor so I don't know how well it works. You should take a look at the WiiDAR project. They show how to make a lidar using a wii controller.
As you know its all about the weight. More…"

"In simple terms. The magnetometer gives you a reference location as you rotate ( ei where north is). Using that reference, you can calculate your rotational speed, which tells you how long it takes to complete a full revolution. Knowing this, you…"

"Great work! I'm currently working on implementing a PID to do altitude hold and wall avoidance. I built the first powered monocopter at ERAU back in 2008 and I've loved then ever since. I would love to help with this project.  "