Jon's Project Pages

Tested on MacOs Sierra 10.12.6 and Virtualbox 5.2.18 (Oct 2018) Firstly, ignore advice about having to disable System Protection Integrity, it’s erroneous. csrutil status System Integrity Protection status: enabled. Ok, here are the steps: Insert an sdcard into the slot - MAKE VERY SURE YOU HAVEN’T FLICKED THE WRITE PROTECT SWITCH ON THE CARD - it’s very easy to accidentally move it on insertion if it’s loose. Carefully use a pin to push it back to READ/WRITE mode.

For a gentle introduction to cross compiling for the pi with Docker try here First we need a Docker image with the cross compilation tools installed, so we’ll grab the one from above: docker pull mitchallen/pi-cross-compile Create the build directory & cd into it git clone git://git.drogon.net/wiringPi Create a lib structure mkdir -p usr/local/bin usr/local/lib usr/local/include usr/lib Even though we use the pitools version of ldconfig it still looks in /etc/ld.

PRU’s on the Beaglebone - ( Using UIO with the TI Kernel ) The Sitart AM335X chip used on the Beaglebone series of microcontrollers, as well as having the main ARM core also contains 2 independent 32bit 200MHz controllers known as Programmable Realtime Units (PRU’s). They don’t use an interrupt system, making them completely deterministic & therefore great for doing time critical tasks such as waveform generation. Most instructions take a single clock cycle (5ns) to execute so things like sending an infra red remote signal or controlling RF433 based equipment is easily within it’s capabilites.

This article describes how to use the Beaglebone black to communicate with cheap remote control sockets using RF433. There’s plenty of other posts out there describing how to communicate using the Arduino or ESP8266 platform, using their respective rc-switch & rf-switch libraries. However I wanted to take advantage of the Beaglebone’s built in PRU’s. They’re perfect for doing time timing critical tasks such as this. The Mercury RC-5 Sockets I used are readily available in the UK.