This page is a placeholder about ultrasonic sensors, which we hope to flesh out as time permits.
I've been using a driver board from PiBorg called the UltraBorg that has both support for four servos and four HC-SR04 ultrasonic sensors, with a support library in Python.
These are sorta a step up from the SR04 in terms of quality, an intermediate-level ultrasonic sensor, certainly pricier than the SR04 but less cost and complexity than the more advanced SensComp (see below).
The HRLV-ShortRange-EZ1T is our most recommended HRLV-ShortRange-EZ Sensor for people detection, autonomous navigation and well balanced detection.
Product page: https://www.maxbotix.com/ultrasonic_sensors/mb1614.htm
A more advanced sensor is available from SensComp, which uses a transducer similar to those found in the Polaroid SX-70 Sonar camera, circa 1978. These sensors are have a longer range and are more sensitive than their cheaper brethren. I contacted SensComp and received more information about their sensors. See the documents attached to this page.
According to SensComp there is currently no known Python port of the Arduino C code, but the Ping_SMRT.ino file looks to be relatively straightforward if the included Wire.h and LiquidCrystal_I2C.h library are themselves either ported or portable. But this is certainly a non-trivial effort.