Copy of std Ultrasonic range, but returns Max distance on failure so we can assume nothing close to us. My sensor seems to go low on ping capture, not success, so I changed timeout to max round trip to get full range.
Egg Incubator controls..21 or 28 days, rotate right/left, over/under temp alarm, candle reminder, mist reminder or trigger and move to brooder reminder, humidity control
http://osoyoo.com/2017/07/24/arduino-lesson-obstacle-avoidance-sensor/
This object inverts the return to show True when the sensor detects an obstacle.
The Enable Pin is onlused on the 4 Pin version of this sensor and is used to turn the pin on and off.