Back in dicks-raspberry-pi.blogspot.com, post 68, I described my frustrations with rangefinders. I've moved on from my urge to create an electronic "white cane" for the visually impaired, but just maybe an adequate device is now available. It's described at
www.maxbotix.com/Ultrasonic_Sensors/MB7051.htm. Pricy though, over $150.
A secondary problem I mentioned in the old post was that an Arduino Nano wasn't fast enough to keep up with both the rangefinder and the 3-axis accelerometer. Well, if you replace the Nano with an equally small but faster Particle Photon that issue (probably) goes away.