The module described here makes it possible to retreive the distance detected by the proximity detector PmodSONAR.
This module constantly outputs the distance measured by the SONAR Pmod. The output value (data_out) roughly changes each 49ms and is always valid. It represents the distance beween the SONAR Pmod and the closest obstacle expressed in inches (2.54cm). data_out is 8 bits unsigned, so the maximal measurable distance is 255in.
If the obstacle is closer than 6in, the Pmod output is unstable and meaningless (generally equal to 5 or 6)