We’re using these (https://www.amazon.ca/HC-SR04-Ultrasonic-Distance-Arduino-MEGA2560/dp/B01COSN7O6/ref=mp_s_a_1_4?keywords=ultrasonic+sensor&qid=1582048623&sr=8-4) sensors and they work great. You can just connect them to the DIO ports and they work great, you just use the Ultrasonic class in WPILib for the code. See this post (HC-SR04 Ultrasonic Distance Sensor wiring and programming) for how to wire them.