>A Ping ultrasonic ranging module can measure distance based on the time it takes for sound to travel to an object and for the echo to return to the module. The user must provide a positive logic pulse to generate the burst of ultrasound (bang). Immediately after the bang, the module output goes HIGH until the echo is detected and it goes back LOW. The time HIGH for the output pulse is proportional to the distance from the object that caused the echo. However, the Ping
module has only a single pin that serves as both input and output. Use tristate buffers and any logic gates necessary to allow a single active-HIGH push button input to pulse the signal pin and immediately after
this pulse is finished to allow the signal pin to drive an output.

The textbook doesn't explain the application of tristate buffers very well. From what I understand, they can be HIGH, LOW, or Z-hi. From my understanding, the same pin (push button?) must drive the input as well as output. So, feed pulse into a pin, sensor is HIGH, echo detected, sensor is LOW, all on the same pin?

I have tried drawing a few schematics but it is obvious I don't know what I'm doing and I'm wasting a lot of time when I should be focusing on the fundamentals.