Ultrasonic is an ultrasonic distance measuring sensor unit, with the capability of simultaneous reception and transmission. The ultrasonic probe has a sound frequency of 40KHz, a direction angle of ±20 ° and an accuracy of 1mm. The internal part is calculated by an RCWL-9600 ultrasonic distance measuring chip, and the measurement results can be directly obtained through I2C interface (0x57). The effective distance is 30 - 150cm.