For my next "top secret" robot project I need 2 ultrasonic sensors. Playing around with the Maxbotix MaxSonar EZ1, which perfectly matches in size for this task, I stumbled across the following problem.
Running only one sensor works like expected. But running two at the same time, don't work. Lucky for me, Maxbotix has a solution for this problem, called daisy chaining. After testing all possible options the Constantly Looping Mode was the best choice for me. After all, it works like a charm.
Here is the schematic so far. Later on a Duo-LED and a LDR sensor for ambient light will be added to each sensor.