I have installed a set of Linux packages from a directory of .deb files. I then wanted to uninstall them, but trying to guess the package names was hard – even harder was wading through the sheer amount of files to remove them! Linux has this weird thing where you can installed from anyrandomname.deb file, but you have to remove by package name.

A bit of Googling and some short script work got me this:

#!/bin/bash

for f in *.deb;
do
 pak="$(dpkg-deb -f "$f" Package)";
# echo $pak $pak
 sudo apt-get remove $pak ;
done

Every deb file is listed, examined and the packages listed then uninstalled by package name. While there may be more elegant ways, this seems to work!

Back in the day telephone numbers represented a house. People in organisations or from domestic dwellings would call houses and then ask for the person to whom they wanted to speak. Today we call another’s mobile and almost disregard what number we are calling, or use any number of mobile apps which ignore the whole idea of telephone numbers such as WhatsApp.

But he main purpose of fixed line numbers today seems to have become finding out who called you, and ignoring them. This can be done from a mobile of course, but think about this:

1. We used to have printed telephone directories when you wanted to call someone else’s house.
2. Commercial organisations would list their names in a colourful printed directory, sometimes call the Yellow Pages (or blue or pink in other countries).
3. We would find people through directories and contact them via their fixed line telephone number.

So the important points are that:

• People/organisations would be discovered through a directory
• Numbers represented the route to contact that person or organisation

Present day

Today, the main use for fixed lines numbers seems to be typing them into Google and trying to work out ‘who called me’ – the plethora of web sites which provide such services seems to indicate that it is a growth business!

Following the theory that the best new businesses are those which remove part of an established process (think Uber – remove the payment, think AirBnB – remove the property) then we have moved to the place that telephone numbers have all but disappeared, and which specific telephone number we have is almost irrelevant, since no-one dicovers us, nor contacts us anymore through the use of a string of digits.

Many times when I have led Design Thinking classes one observation I have made is that those workshops don’t work well if there are ‘observers’. Whatever reason they may have, people who are not engaged with the participants – either talking amongst themselves, or absorbed in reading their email on laptop or phone, destroy the energy and engagement in the room.

Sometimes it is hard to deflect them – one occasion was that a senior manager from my organisation wanted to “see the effects” of a design workshop and joined us, only to sit doing their email on a laptop in the middle of the classroom. Other times it is because some urgent business reason has arisen and a student needs to communicate with other colleagues in the business – which is a perfectly valid reason and should take priority.

I no longer allow them, and gently suggest that they should either participate or leave the room. If events arise I believe that a professional person should either (a) step outside the room and deal with the matter, or (b) excuse themselves from the duration of the class. I’m happy with both: we are adults and you don’t need my permission, but to get the best outcomes for both yourself and the rest of the class I need you to:

Be Here Now!

My current project is a clock using electronic paper which will run on batteries, access the internet to set the local time using the ntp protocol, and use a real-time clock to maintain accuracy.

Alternatives

I considered a number of ways of coding and controlling this display. Fundamentally I’d have to drive one of these e-paper displays, and secondly run from battery for long periods. Ideally I’d like to connect to it via wifi to update code and change things, and the clock would be a real-time clock driven by an accurate crystal with battery backup. My options seem to be:

1. Single board computer with full Linux operating system
   • Odroid C1+
   • Raspberry Pi Zero
   • … your favourite SBC
2. Embedded controller (of which the Arduino is a well-known type)
   • Arduino
   • Adafruit Feather platform
   • Particle Proton
   • Micropython PyBoard

List of components

1. Arduino Uno, for initial prototyping
2. Embedded Artists EM027BS013 from Cool Components
3. Adafruit Feather HUZZAH using the ESP8266 wifi chip
4. Adafruit PowerBoost 500
5. Adafruit Precision RTC featherwing daughter board

The HUZZAH board forms the main part of the clock with it’s ESP8266 ability to create a wifi access point, or join a existing wifi network. It can also be programmed using the Arduino IDE which is an advantage for those familiar with that environment. The PowerBoost may not be necessary as the HUZZAH provides a JST battery connector and can charge a LiPo/LiIon battery already, while the RTC daughter board will keep the time stable over extended periods.

The story thus far

On considering the single-board computers such as the Raspberry Pi I realised the power requirements of keeping a full OS and file system up meant that my clock would only run for about 9 hours maximum before needing a charge. There are plenty of comparisons around showing the differences between embedded controllers such as the Arduino versus the SBCs, but suffice to say that I thought achieving low power was easier with the controllers. The ease of programming the SBCs keeps me looking at something like a RaspPi Zero to see if it can be switched to low power, but I’m leery of starting down that route before exploring the other options.

Getting the Arduino controlling the display was easy.

As the Embedded Artists display is using the RePaper / Pervasive Displays reference model and their code is up on GitHub made it easier to get help and understand what was driving where. I also found that Google was my friend, although getting the Arduino driving the display was simpler than moving that code onto the Adafruit.

Starting with the Arduino Uno was easy as Embedded Artists have the code up on Github for that and a couple of example programs. Very quickly I realised that there were two different versions of the display (revisions A,B,C) and I had the second one, revision D. This used a different pinout arrangement and the display started to look muddy and with multiple ghosted images. Once using the correct Git repo things quickly turned right and the demo programs could be run.

Feather HUZZAH

The Adafruit Feather HUZZAH is an excellent platform in a small form factor, and with lots of support and documentation. I was impressed and also purchased the ‘Featherwing RTC’ as a precision real-time clock.

However the lack of GPIO pins on that particular Feather board meant that I could not have controlled the display – perhaps other e-ink displays have less control lines but mine needed around 10 GPIO pins free.

Micropython

I’ve been a fan  of Damien George’s micropython since the early Kickstarter days, and twice supported it – for the initial board and the implementation onto the ESP8266. I love the language, but have never found a place to use it as the SBCs kept me busy with their Linux OSes and things such as Node-RED and Ethereum. But these Python boards are excellent and low-powered, and I get to program in a language I like. An unexpected gift was Peter Hinch’s full library for the Embedded Artists display – this demonstrates to me what a professional micro-controller programmer can do, even if he is retired!

So I may go down the micropython board route and ignore the wifi requirement for the moment. My version 1.0 board does not have pads for a JST battery connection although the v1.1 boards do, plus it already has a RTC that can be backed with a coin battery.

1. Open tab in browser
   1. go to video game site
   2. download it
   3. played it
   4. noticed save game button
2. Thought of ways to hold save games between computers, such as Linux or Windows.  After all, this was a cross-platform game!
   1. Box/Dropbox or similar?
   2. Owncloud (I used to run this on an older server)
   3. I have a SBC which is not in heavy use
   4. I have a 1TB USB drive which could hold Owncloud server …
3. Installed Owncloud
   1. proxy rules on my nginx front-end server
   2. php installed on backend
   3. mariadb rather than MySQL
      1. there isn’t a executable for ARMhf
         1. download
         2. compile
   4. Went with MySQL because at least this works on ARMhf and there are executables in the repo
4. … and so on.  I didn’t play that game again so all the above was lost, however I DO now have a great mechanism for sharing between computers.

This tale of distraction isn’t unique I know – XKCD wrote about it and we’re all afflicted in some degree, but it is interesting to me how much of my day is based around following-the-white-rabbit down the rabbit hole.  All good stuff!

My new home treadmill arrived several days ago, and having fought off a bout of flu I have started using it.  It is positioned under my Ikea standing desk which is much MUCH cheaper than the ‘official’ ones – it is a Frederik desk like here, and they really do work well.

The treadmill is a domestic one sold by a UK reseller, although most likely sourced from China somewhere.  The important point is that it is quiet, low, and slow.  I won’t be running a marathon on this thing and it isn’t meant to go fast like a gym one.  Instead, continual slow sessions of walking will accumulate into a workout will still meaning I can take conference calls and work at the desk.

This piece has been written while using it and I have to say it is a really, really easy thing to get used to.  I was impressed by Stephen Wolfram (of Mathematica fame) who used one, and also Neal Stephenson and his diatribe Arsebestos wherein he explains just how much sitting down is killing us.  Now, I don’t take that as evidence nor my own annecdotal experience but I do observe that when I used a standing desk I never had any back pains, and when I gave up for some time and re-used an office chair I ended up with a sacro-illiac joint problem which extended painfully for some months.  So back to the standing desk, and now the treadmill, and onwards to Skeletor!^*

^* (A character in Stephenson’s Reamde who is a lore writer).