As the Uno Rev3 only has 14 digital I/O pins and six analog input pins, it's best suited for projects not requiring too many components. Most of the built-in examples in the Arduino IDE software ...

The Arduino team gives a few examples of what you can build using the MKR IoT Carrier Rev2 board : – Environment monitoring stations.

That’s right, these parking sensors are powered by an Arduino board, and the only extra components that were used in the project are a HC SR04 ultrasonic sensor, an active buzzer, and jumper wires.