Default value for maximum measurement distance is 4m, since HC-SR04 sensor can't measure reliably beyond that. However, if you are using another sensor or if you you don't care about distances larger ...
Get an online offer in 2 minutes using our Sell My Car tool.
The repository includes a variety of sensor-specific libraries, firmware, and example code that can be used to build and connect sensors to a wide range of platforms, including Arduino, Raspberry Pi, ...