Real‐Time BeagleBone Interfacing
Derek Molloy · 2014
This chapter deals with real-time interfacing with the BeagleBone. The BBB has two programmable real-time units (PRUs) that can be used for certain real-time operations, and these are the focus of the chapter, which describes input and output examples that help explain the operation of the PRUs and their encompassing industrial communication subsystem (PRU-Industrial Communication Subsystem (ICSS)). The real-time capabilities of the BBB are demonstrated using two applications: the first generates a custom waveform on a GPIO, and the second uses a low-cost ultrasonic distance sensor that requires precise timing in order to communicate the distance to an obstacle. Two additional tools can aid with development for the PRU-ICSS. The first is a PRU debugger and the second is a TI C compiler that can be used to write PRU programs, in place of writing assembly code.