ardupilot/Tools/Linux_HAL_Essentials/pru/rangefinderpru
..
AM335x_PRU.cmd
HexUtil_PRU.cmd
Makefile
README.md
pru_ctrl.h
rangefinder.c
rangefinderprudata.bin
rangefinderprutext.bin

README.md

PRU firmware for HC-SR04 rangefinder

HC-SR04 driver that can be used with BeagleBone Black

Install PRU C-Compiler

  1. sudo apt-get update
  2. sudo apt-get install ti-pru-cgt-installer

Rebuild rangefinder.c

  1. cd ardupilot/Tools/Linux_HAL_Essentials/rangefinderpru/
  2. make