We are using four of the Maxbotic EZ-1 Sonar sensors, which turned out to not be so “easy” when using more than one sensor. The sensors send out a sonar which bounces off an object allowing a distance calculation to be returned. There is a good tutorial for getting started with the sensor on Adafruit, but we needed a bit more functionality.
We wired the sensors as shown below communicating between the sensors with RX/TX. The pdf instructions of the image below can be found here.
The hurdle we had to overcome with the sensors is because of the sonar. When the sensors are pointed in the same direction, they create noise and interference if they are triggered at the same time because one sensor picks up the sonar from another. We solved this issue by daisy chaining the sensors together and triggering them at different times. This way, each sensor would get an accurate reading without interfering with the signal from the other sensors.
We embedded the sensors into the legs to make them as discrete as possible. The sensor does not see the box or the table since they are close to the edge. We drilled holes through the bottom of the box and ran the wires up inside so they would be hidden from view.