Ultrasonic Sensor Walking aid 3DX

My wife has a tough time seeing. When we are out walking you have to tell her when there are steps so that she does not trip or fall down. Because of this I decided to design a handheld device that could tell her when the ground changes either up or down using a ultra sonic sensor and two LED lights. Red for step up, yellow for step down.

The program captures the distance and compares the next captured value and flashes the appropriate lights or none at all.

I designed the handle to inc