The Makeblock mBot is one of the best kits I have seen for learning the basic of robotics. The kit is relatively inexpensive ($70 USD), making it ideal for STEM programs that wish to explore the field of robotics. The mBot mCore board is based on the Arduino Uno (Atmel 328P) and comes with the following sensors:
- Infrared Receiver
- Light Sensor
- Line Follower Sensor
- Momentary Contact Button
- Ultrasonic Sensor
It also comes with the following components:
- Onboard Buzzer
- 2 RGB LEDs
- Infrared Transmitter
- 2 Motors
Earlier versions of the mBot could be orderd with a WiFi module that enabled a computer to send commands to the mBot as well as the Bluetooth module that accompanies the current version that provides the same capabilities. You can get full list of everything that comes with the basic kit here.
Makeblock also provides a Scratch 3.0-based visual programming environment that can be downloaded here which allows middle and high school students to leverage an environment that is likely familiar to them. This environment also supports programming in Python, one of the most popular programming languages today.
Additionally you can write programs in C/C++ with the Arduino development environment, an approach that allows the students to get close to the bare metal. So all things considered, I can heartily recommend the kit for those wishing to learn or teach robotics and its attendant disciplines.
I should also mention that I wrote an ebook, A Gentle Introduction to Robotics, (link) that is based on the older version of the Makeblock environment (Scratch 2.0-based) a few years ago that contains several sample applications ranging from turning the onboard LEDs on and off to a maze solving application. The concepts are still relevant and I will update the book at some point in the future to use the current Makeblock environment.