Aside from the Uno and the ultrasonic sensor, you also need a PHPoC Shield to connect the board to the internet and a power supply to power up your Arduino.

The Arduino UNO R4 boasts a 3x performance increase over the UNO R3 and , in addition, SRAM has been upgraded from 2kB to 32kB, and flash memory from 32kB to 256kB to support more complex projects.

Two new variants of the Arduino Uno development board, the lightweight Uno R4 Minima and the full-fledged Uno R4 WiFi, are each powered by a 32-bit microcontroller. These next-generation Uno boards ...

Arduino has launched its next generation of UNO boards, introducing a 32-bit Renesas microcontroller and Espressif ESP32-S3 module, one-click cloud connectivity and plenty of I/O plus a 12×8 red LED ...