v4.0.0 is a BETA release of the TS8000 library that adds functions to perform a very basic ultrasonic time-of-flight (ToF) measurement. The additional functions utilize TC and TCC timer peripherals, which require microcontroller-specific code to configure, so the BETA release targets a specific microcontroller, the SAMD21 (Arduino ZERO).
However, the ToF measurement itself is not particularly difficult to make, so the code should be fairly intuitive to port to another microcontroller architecture, with the hardest part being configuring the timers and interrupts on your specific target micro.
The readme.md and example sketch include a connection diagram for hooking up a simple circuit to transmit and receive an ultrasonic pulse train.
We wanted to get this version out there so developers could start playing with very basic ultrasonic TX / RX capability, but the code, although functional, is immature and still needs cleanup and likely re-architecting.