I’ve now arrived in Shenzhen, China, which is the electronics capital of the world. I’m busy recording video and taking photos so that I can show everyone what it’s like here in the most high-tech city in the world.
This was the view from my hotel room window when I arrived last night:
Click the image for a larger version. It’s worth it!
The octagonal building you can see to the left that disappears above the top of the photo is SEG Plaza, the heart and soul of the electronics industry here. Every other commercial building you can see in that photo (and going out many blocks in every direction) is directly related to electronics manufacturing. There are entire buildings full of nothing but LED vendors. Buildings for case manufacturers. Buildings for cell phone parts. Buildings for LCD panels, both bare (OEM) and retail ready, and every stage in between.
If you’re interested in electronics and you haven’t heard of Shenzhen or the Huaqiangbei markets before, the next few videos that I upload will be eye-opening.
For many years now my friend Karl von Moller has been interviewing people within the Australian electronics industry to build a picture of the state of the industry, and to report on where it’s going.
The latest chapter is now up on YouTube. It features many local engineers and Makers, including myself, so you can see what I looked like when I briefly had the start of a beard! Karl will be travelling to Shenzhen, China with me at the end of next week, and this episode is a prelude to what will be reported back after that trip. The video thumbnail is actually me watching my DIY pick-and-place machine populating an ESP-8266 based PCB, and much of the background footage (including footage of Angus from Espressif working on that same board) was recorded in my lab.
I’m finally taking the step of adding an online store to the SuperHouse site to make it easier to share parts for my projects. I often have people ask where they can buy boards I’ve designed for the projects in SuperHouse, so now I’ll be able to list them for sale.
My home automation light switches have gone through a series of versions, starting with very complicated switches that all had Ethernet built in. Over time I’ve simplified the system so now the light switches themselves are electrically very simple: they’re just illuminated buttons on a breakout board with an RJ45 connector, and absolutely nothing else in them.
The switches connect to a pair of centralised light switch controllers over Cat-5 cable, so that it can detect when the buttons have been pressed and report events to MQTT.
In this episode I show some of the previous versions of my light switches, and then show how I built an Arduino based light switch controller.
There’s also a general introduction to the I/O breakout schema that I use at I/O Breakout. I’ll probably cover this in detail in a future episode because the same breakout shield will be used in other projects.
The light switches themselves are just illuminated buttons on a breakout board, mounted on a standard wall plate. The 4-button panel uses all 4 available data lines. The 3 and 2 button panels simply use fewer data lines. Click on the schematic for a larger version:
I didn’t spend much time in this episode explaining the current version of my light switches because I’m going to cover it in much more detail in the future. This episode is mostly about the controller.
After years of using cheap lino cutting mats from the $2 shop, I’ve finally put proper ESD mat down on my electronics benches.
I wanted to use a nice blue mat, but Dave Jones (@eevblog) had a bad experience with discoloration so I decided to try plain grey instead. Hopefully this won’t end up going a strange green colour like Dave’s.
I got the mat from Oritech in Sydney. Their full range is listed here:
I’ve been lucky enough to have worked with an electrician to totally rewire my house for home automation, so it works in a very different way to a normal house. This episode traces through how power arrives at my house, is distributed to a pair of sub-switchboards, and from there goes out to loads such as lights. It also covers the important pieces of the system including MQTT and OpenHAB.
General information about MQTT is available at the official MQTT site. The site doesn’t get many updates because the protocol standard itself is fairly stable and well established, but it’s a good reference site with links to many MQTT-related projects. See mqtt.org.
There are many MQTT broker implementations available, written in various programming languages and with different features and levels of performance. I use Mosquitto, which has been around for many years and has never let me down. Note that your MQTT clients won’t care what broker you use or what language it’s written in, provided it supports the features they need. Mosquitto is written in Java, but I typically connect to it from Arduino-based devices. See mosquitto.org.
OpenHAB is currently the main rules engine that I use, which also takes care of state management and provides an app for iOS and Android. I’m still running the v1.x release series, but v2 is out now which is a major rewrite. See openhab.org.
For a general purpose rules engine that communicates using MQTT, check out Node-RED. With a drag-and-drop editor based on Node.js, you can create rules right in your browser. I don’t currently use this, but I’ll probably replace my current home-brew rules engine with Node-RED some time in the future. See nodered.org.
I listen to dozens of podcasts, and I usually have one playing while I’m working on electronics projects in my workshop. The speaker in my iPhone is ok, but I wanted to get some kind of external speaker to give it a bit more volume.
BlitzWolf kindly sent me a BW-F4 Bluetooth speaker to use in my workshop. I’m not really into music (I’d rather spend my time listening to something that teaches me new things) so I can’t give an opinion on its sound fidelity, but so far it’s been great for listening to podcasts.
The BW-F4 charges by USB and can run from battery for most of the day.