Made by Mikal – Page 20

Introducing GangScan

Post author:mikal
Post published:April 5, 2019
Post category:Gang Scan

As some of you might know, I am a Scout Leader. One of the things I do for Scouts is I assist in a minor role with the running of Canberra Gang Show, a theatre production for young people. One of the things Gang Show cares about is that they need to be able to do rapid roll calls and reporting on who is present at any given time -- this is used for working out who is absent before a performance (and therefore needs an understudy), as well as ensuring we know where everyone is in an environment that sometimes has its fire suppression systems isolated. Before I came along, Canberra Gang Show was doing this with a Windows based attendance tracking application, and 125kHz RFID tags. This system worked just fine, except that the software was clunky and there was only one badge reader -- we struggled explaining to youth that they need to press the "out" button when logging out, and we wanted to be able to have attendance trackers at other locations in the theatre instead of forcing everyone to flow through a single door. So, I got thinking. How hard can it be to build…

Brilliant Smart Wifi plug with Tasmota

Post author:mikal
Post published:March 26, 2019
Post category:HomeAssistant

A couple of weeks ago I was playing with Tuya derived smart light globes (Mirabella Genio from K-Mart Australia in my case, but there are a variety of other options as well). Now Bunnings has the Brillant Smart Wifi Plug on special for $20 and I decided to give that a go as well, given it is also Tuya derived. The basic procedure for OTA flashing was the same as flashing the globes, except that you hold down the button on the device for five seconds to put it into flash mode. That all worked brilliantly, until I appear to have fat fingered my wifi details in Tasmota -- when I rebooted the device it never appeared on my network. That would be much more annoying on the globes, but it turns out these smart plugs are really easy to open and that Tuya has documented the pin out of the controlling microprocessor. So, I ended up temporarily soldering some cables to the microprocessor to debug what had gone wrong. It should be noted that as a soldering person I make a great software engineer: Once you've connected with a serial console, its pretty obvious who can't be trusted to…

I, Robot

Post author:mikal
Post published:March 16, 2019
Post category:Book

Not the book of the movie, but the collection of short stories by Isaac Asimov. I've read this book several times before and enjoyed it, although this time I found it to be more dated than I remembered, both in its characterisations of technology as well as it's handling of gender. Still enjoyable, but not the best book I've read recently.

Mirabella Genio smart lights with Tasmota and Home Assistant

Post author:mikal
Post published:March 8, 2019
Post category:HomeAssistant

One of the things I like about Home Assistant is that it allows you to take hardware from a bunch of various vendors and stitch it together into a single consistent interface. So for example I now have five home automation vendor apps on my phone, but don't use any of them because Home Assistant manages everything. A concrete example -- we have Philips Hue lights, but they're not perfect. They're expensive, require a hub, and need to talk to a Philips data centre to function (i.e. the internet needs to work at my house, which isn't always true thanks to the failings of the Liberal Party). I'd been meaning to look at the cheapo smart lights from Kmart for a while, and finally got around to it this week. For $15 you can pickup a dimmable white globe, and for $29 you can have a RGB one. That's heaps cheaper than the Hue options. Even better, the globes are flashable to run the open source Tasmota stack, which means no web services required! So here are some instructions on flashing these globes to be useful: Buy the globes. I bought this warm while dimmable and this RBG option. Flash to…

What If?

Post author:mikal
Post published:March 4, 2019
Post category:Book

More correctly titled "you die horribly and it probably involves plasma", this light hearted and fun read explores serious answers to silly scientific questions. The footnotes are definitely the best bit. A really enjoyable read.

Abaddon’s Gate

Post author:mikal
Post published:February 18, 2019
Post category:Book

This is the third book in the Leviathan Wakes series by James SA Corey. Just as good as the first two, this is a story about how much a daughter loves her father, perhaps beyond reason, moral choices, and politics — just as much as it is the continuation of the story arc around the alien visitor. Another excellent book, with a bit more emphasis on space battles than previously and an overall enjoyable plot line. Worth a read, to be honest I think the series is getting better.

The Gentle Art of Swedish Death Cleaning

Post author:mikal
Post published:January 31, 2019
Post category:Book

We've owned this book for a while, but ironically Catherine lost it for a bit. It seems very topical at the moment because of the Marie Kondo craze, but its been floating around our house for probably a year. The book is written by an 80+ year old and explains the Swedish tradition of sorting your stuff out before you keel over, which seems like a totally reasonable thing to do when the other option is leaving your grieving kids to work out what on earth to do. The book isn't as applicable to people not at the end of the lives -- it for example recommends starting with large things like furniture and younger people are unlikely to have heaps of unneeded furniture. That said, there is definitely advice in here that is applicable to other life stages. The book is composed of a series of generally short chapters. They read a bit like small letters, notes, or blog posts. This makes the book feel very approachable and its a quite fast read. I enjoyed the book and I think I got some interesting things out of it.

Best Foot Forward

Post author:mikal
Post published:January 27, 2019
Post category:Book

Catherine and I have been huge fans of Adam Hills for ages, so it wasn't a surprise to me that I'd like a book by him. As an aside, we've never seen him live -- we had tickets for his show in Canberra in 2013, but some of us ended up in labor in hospital instead, so we had to give those tickets away. One day we'll manage to see him live though, he just needs to get back to touring Australia more! Anyways, I enjoyed this book which as mentioned above wasn't a surprise. What was a surprise is that he said something interesting which I have been pondering for the last few days... Basically, its nice to get on stage and say things, either entertaining the audience or in my case perhaps educating them a little (I give technical conference talks). However, that's not the most important thing. You need to work out why you're on that stage before you go out there. What is the overall thing you're trying to convey? Once you know that, everything else falls into place. I think this is especially true for keynote speeches, which need to appeal to a more general audience than…

Support for Raspberry Pi and Orange Pi GPIOs in Home Assistant

Post author:mikal
Post published:January 15, 2019
Post category:Conference HomeAssistant Python

So, I've been off in the GPIO library salt mines for a while, but am now ready to circle back and document how to get GPIO inputs and outputs working in Home Assistant. This now works on both Raspberry Pi and OrangePi, assuming that my patch gets merged. First off, let's talk about GPIO outputs. This is something which has been working for a while on both platforms (a while being a week or so, assuming you've patched Home Assistant with my pull request, but you're all doing that right?). To configure an output in Home Assistant, you would add the following to configuration.yaml: rpi_gpio: board_family: orange_pi switch: - platform: rpi_gpio ports: PA7: LED Where board_family can be either "raspberry_pi" or "orange_pi". Note that for Raspberry Pis, the pin numbers are always numbers whereas for OrangePi we are using "SUNXI" numbering, which is of the form "PA7". The circuit for this LED is really simple: Now we have a switch we can control in Home Assistant: GPIO inputs are similar. The configuration looks like this: rpi_gpio: board_family: orange_pi binary_sensor: - platform: rpi_gpio invert_logic: true ports: PA7: PUSHYBUTTON With a circuit like this: invert_logic set to true is required because our…

Updated examples for OrangePi GPIOs

Post author:mikal
Post published:January 14, 2019
Post category:Conference Python

As part of working through adding OrangePi support to Home Assistant, Alastair and I decided to change to a different GPIO library for OrangePi to avoid the requirement for Home Assistant to have access to /dev/mem. I just realised that I hadn't posted updated examples of how to do GPIO output with the new library. So here's a quick post about that. Assuming that we have an LED on GPIO PA7, which is pin 29, then the code to blink the LED would look like this with the new library: import OPi.GPIO as GPIO import time # Note that we use SUNXI mappings here because its way less confusing than # board mappsings. For example, these are all the same pin: # sunxi: PA7 (the label on the board) # board: 29 # gpio: 7 GPIO.setmode(GPIO.SUNXI) GPIO.setwarnings(False) GPIO.setup('PA7', GPIO.OUT) while True: GPIO.output('PA7', GPIO.HIGH) time.sleep(1) GPIO.output('PA7', GPIO.LOW) time.sleep(1) The most important thing there is the note about SUNXI pin mappings. I find the whole mapping scheme hugely confusing, unless you use SUNXI and then its all fine. So learn from my fail people! What about input? Well, that's not too bad either. Let's assume that you have a button in a…