Alastair D'Silva

At Linux Conf 2019, I'll be running a home automation workshop, based on Home Assistant and my 1Wire home automation devices.

I recently had a MyRepublic NBN connection installed, and was provided with a Technicolor TG789vac V2 VDSL2 modem. It arrived quite locked down, in routed mode it could not deal with the complexity of my network (multiple VLANs), and in bridge mode it bridged the VDSL2 interface to the Wifi connection, but not Ethernet!

This is a 3d printed fan shroud that I designed and 3d printed myself. It is made from durable ABS plastic, and allows you to connect a 125mm flexible duct to your miner's exhaust, allowing you to vent the hot air directly outside (or in winter, into your air conditioning ducts).

The mount features a negative taper, such that pulling on the duct increases the clamping force.

You will need 4 50mm M4 machine screws, and a 125mm diameter screw clamp to fasten the ducting on.

One of my 3D printers has been acting up recently - the right extruder heater is stuck on, rendering the machine unusable.

Our airconditioner gives a "C5" Error when in heating mode, which is annoying as Canberra gets quite cold in winter.

Looking at the list of error codes, it shows that C5 is a thermistor failure on the indoor gas pipe. Opening the indoor unit and measuring the resistance of the thermistor shows it in the ~2.8MOhm range, well outside what it should be.

I'm currently working on a 1wire library for mbed, so that 1wire devices can be implemented on mbed compatible microcontrollers (really, just STM32 for now).

One of the things that would be really useful is to be able to update the firmware of these devices over the 1wire bus, so that they don't need to be decomissioned for updates.

It took me a while to figure this one out, the docs online were pretty thin, so I'm putting this here to help the next person who gets stuck.

There are 2 tricks here.

1. It's not clear how to get the workspace in GroovyAxis. It has to be accessed through the 'context' object, but is null when the script is run when the job is saved. It is populated when the job is built.
2. The workspace exists on the slave node, but the Groovy script is run on the master. You must use the FilePath object to correctly access the files on the slave

I also needed a ubuntu image. Creating this was for less painful than the Fedora image:

• curl -o debootstrap.sh     https://raw.githubusercontent.com/docker/docker/master/contrib/mkimage/d...
• chmod 755 debootstrap.sh
• sudo ./debootstrap.sh ubuntu --components=main,universe trusty
• sudo tar -C ubuntu -c . | docker import - ubuntu:14.04.4
• docker tag ubuntu:14.04.4-new ubuntu:14.04

Docker is a great way to fully describe and implement an installed Linux environment, and we make use of it at work as part of our continuous integration system to provide a clean environment for the jobs that we run.Unfortunately, the main public repo (docker.io) currently only contains images for x64, so if you want a different architecture, you may need to build it yourself.

In this situation, I required a Fedora 23 image on Power PC. I started with a working Fedora 23 in PowerKVM.

The problems I had to address:

A while ago I got hold of a couple of DLink DIR-865L AC1750 802.11ac routers as there was a generous cashback offer.

I was originally using it as a glorified access point, but since updating my main router to carve off a variety of ethernet segments for home automation, guest networks, etc, I wanted to expose these as different wifi networks, using the DIR-865L units to extend the wifi network, with ethernet backhaul to the main router.

To get OpenWRT onto the router (where the router's IP is 10.0.1.200 and the tftp server is 10.0.1.16):