GrabBot from One-Kit Wonders
This robot is from chapter 9 of the One-Kit Wonders book. If you watch the video, the robot may appear to be very simple. There are however, two things that make GrabBot special.
One of these two is the grabbing hand. Using one motor, it grabs and lifts object, which is a cellphone in this case.
The other is its autonomous behaviour. When I trigger the program to start by saying: "Get my cellphone", it starts searching for the closest object in range. While spinning around, it continously stores a sensor value along with a location in two variables. Then, it returns to the position where it measured the lowest sensor value and grabs the object.
When doing so many redaings from the Ultrasonic Sensor, it functions relatively accurate. It still has a few problems detecting balls, but if they're not too far away, it does find them.
P.S. Book reader Enrique has posted a call to action for One-Kit Wonders readers. Read it here.