The Beer'o'Meter project Daniel Silverstone

As some of you may know, I have been working on a small hardware project called the Beer'o'Meter whose purpose is to allow us to extend Ye Olde Vic's beer board to indicate the approximate fullness of each cask. For some time now, we've been operating an electronic beer board at the Vic which you may see tweeted out from time to time. The pumpotron has become very popular with the visitors to the pub, especially that it can be viewed online in a basic textual form.

Of course, as many of you who visit pubs know only too well. That a beer is "on" is no indication of whether or not you need to get there sharpish to have a pint, or if you can take your time and have a curry first. As a result, some of us have noticed a particular beer on, come to the pub after dinner, and then been very sad that if only we'd come 30 minutes previously, we'd have had a chance at the very beer we were excited about.

Combine this kind of sadness with a two week break at Christmas, and I started to develop a Beer'o'Meter to extend the pumpotron with an indication of how much of a given beer had already been served. Recently my boards came back from Elecrow along with various bits and bobs, and I have spent some time today building one up for test purposes.

As always, it's important to start with some prep work to collect all the necessary components. I like to use cake cases as you may have noticed on the posting yesterday about the oscilloscope I built.

Component prep for the Beer'o'Meter

Naturally, after prep comes the various stages of assembly. You start with the lowest-height components, so here's the board after I fitted the ceramic capacitors:

Step 1, ceramic capacitors

And here's after I fitted the lying-down electrolytic decoupling capacitor for the 3.3 volt line:

Step 2, capacitors which lie down

Next I should have fitted the six transitors from the middle cake case, but I discovered that I'd used the wrong pinout for them. Even after weeks of verification by myself and others, I'd made a mistake. My good friend Vincent Sanders recently posted about how creativity is allowing yourself to make mistakes and here I had made a doozy I hadn't spotted until I tried to assemble the board. Fortunately TO-92 transistors have nice long legs and I have a pair of tweezers and some electrical tape. As such I soon had six transistors doing the river dance:

Transistors doing the river-dance

With that done, I noticed that the transistors now stood taller than the pins (previously I had been intending to fit the transistors before the pins) so I had to shuffle things around and fit all my 0.1" pins and sockets next:

Step 3, pins and sockets

Then I could fit my dancing transistors:

Step 4, transistors

We're almost finished now, just one more capacitor to provide some input decoupling on the 9v power supply:

Finished -- decoupling fitted

Of course, it wouldn't be complete without the ESP8266Huzzah I acquired from AdaFruit though I have to say that I'm unlikely to use these again, but rather I might design in the surface-mount version of the module instead.

Fitted with the module

And since this is the very first Beer'o'Meter to be made, I had to go and put a 1 on the serial-number space on the back of the board. I then tried to sign my name in the box, made a hash of it, so scribbled in the gap :-)

The back of the finished module

Finally I got to fit all six of my flow meters ready for some testing. I may post again about testing the unit, but for now, here's a big spider of a flow meter for beer:

The Beer'o'Meter spider

This has been quite a learning experience for me, and I hope in the future to be able to share more of my hardware projects, perhaps from an earlier stage.

I have plans for a DAC board, and perhaps some other things.

Building an Oscilloscope Daniel Silverstone

I recently ordered some PCBs from Elecrow for the Vic's beer-measurement system I've been designing with Rob. While on the site, I noticed that they have a single-channel digital oscilloscope kit based on an STM32. This is a JYE Tech DSO138 which arrives as a PCB whose surface-mount stuff has been fitted, along with a whole bunch of pin-through components for you to solder up the scope yourself. There's a non-trivial number of kinds of components, so first you should prep by splitting them all up and double-checking them all.

Preparing the components

Once you've done that, the instructions start you off fitting a whole bunch of resistors...

Step 1, fitting resistors

Then some diodes, RF chokes, and the 8MHz crystal for the STM32.

Step 2, fitting diodes, a crystal, and chokes

The single most-difficult bit for me to solder was the USB socket. Fine pitch leads, coupled with high-thermal-density socket.

Step 3, the USB socket

There is a veritable mountain of ceramic capacitors to fit...

Step 4, all the ceramic capacitors

And then buttons, inductors, trimming capacitors and much more...

Step 5, buttons, inductors, trimming capacitors, etc

THe switches were the next hardest things to solder, after the USB socket...

Step 6, Switches, connectors, etc

Finally you have to solder a test loop and close some jumpers before you power-test the board.

Step 7, Test loop and jumper soldering

The last bit of soldering is to solder pins to the LCD panel board...

Step 8, LCD panel

Before you finally have a working oscilloscope

Working oscilloscope!

I followed the included instructions to trim the scope using the test point and the trimming capacitors, before having a break to write this up for you all. I'd say that it was a fun day because I enjoyed getting a lot of soldering practice (before I have to solder up the beer'o'meter for the pub) and at the end of it I got a working oscilloscope. For 40 USD, I'd recommend this to anyone who fancies a go.

A haiku about Haiku Daniel Silverstone

I know I don't mention a season, and I'm a few hours late for hallowe'en, but here's a haiku about Haiku:

A death, once again,
The master sighs, and fixes,
It rises up, undead.

Orchestration, a cry for help Daniel Silverstone

Over the past few years, a plethora of orchestration frameworks have been exploding onto the scene. Many have been around for quite a while but not all have the same sort of community behind them. For example there's a very interesting option in Joey Hess' Propellor but that is hurt by needing to be able to build Propellor on all the hosts you manage. On the other hand, Ansible is able to operate without installing extra software on your target hosts, but instead it ends up very latency-bound which can cause problems when your managed hosts are "far away".

I have considered CFEngine, Chef, Puppet and Salt in addition to the above mentioned options, but none of them feel quite right to me. I am looking for a way to manage a small number of hosts, at least one of which is not always online (my laptop) and all of which are essentially snowflakes whose sparkleybits I want some reasonable control over.

I have a few basic requirements which I worry would be hard to meet -- I want to be able to make changes to my hosts by editing a file and committing/pushing it to a git server. I want to be able to manage a host entirely over SSH from one or more systems, ideally without having to install the orchestration software on the target host, but where if the software is present it will get used to accelerate matters. I don't want to have to install Ruby or PHP on any system in order to have orchestration, and some of the systems I wish to manage simply can't compile Haskell stuff sanely. I'm not desperately interested in learning yet more DSLs, but I appreciate that it will be necessary, but I really don't want to have to learn more than one DSL simply to run one frameworks.

I don't want to have to learn strange and confusing combinations of file formats. For example, Ansible quite sensibly uses YAML for its structured data except for its host/group lists. It uses Jinja2 for its templating and looping, except for some things which it generates its own looping constructs inside its YAML. I also personally find Ansible's sportsball oriented terminology to be confusing, but that might just be me.

So what I'm hoping is that someone will be able to point me at a project which combines all the wonderful features of the above, with a need to learn only one DSL and which doesn't require to be installed on the managed host but which can benefit from being so installed, is driven from git, and won't hurt my already overly burdened brain.

Dear Lazyweb, pls. kthxbye.

Be careful what you ask for Daniel Silverstone
Date: Wed, 01 Jul 2015 06:13:16 -0000
From: 123-reg <noreply@123-reg.co.uk>
To: dsilvers@digital-scurf.org
Subject: Tell us what you think for your chance to win
X-Mailer: MIME::Lite 3.027 (F2.74; T1.28; A2.04; B3.13; Q3.13)

Tell us what you think of 123-reg!

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.style1 {color: #1996d8}

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Well 123-reg mostly I think you don't know how to do email.

In defence of curl | sudo bash - Daniel Silverstone

Long ago, in days of yore, we assumed that any software worth having would be packaged by the operating system we used. Debian with its enormous pile of software (over 20,000 sources last time I looked) looked to basically contain every piece of free software ever. However as more and more people have come to Linux-based and BSD-based systems, and the proliferation of *NIX-based systems has become even more diverse, it has become harder and harder to ensure that everyone has access to all of the software they might choose to use.

Couple that with the rapid development of new projects, who clearly want to get users involved well before the next release cycle of a Linux-based distribution such as Debian, and you end up with this recommendation to bypass the operating system's packaging system and simply curl | sudo bash -.

We, the OS-development literati, have come out in droves to say "eww, nasty, don't do that please" and yet we have brought this upon ourselves. Our tendency to invent, and reinvent, at the very basic levels of distributions has resulted in so many operating systems and so many ways to package software (if not in underlying package format then in policy and process) that third party application authors simply cannot keep up. Couple that with the desire of the consumers to not have their chosen platform discounted, and if you provide Debian packages, you end up needing to provide for Fedora, RHEL, SuSE, SLES, CentOS, Mint, Gentoo, Arch, etc.etc; let alone supporting all the various BSDs. This leads to the simple expedience of curl | sudo bash -.

Nobody, not even those who are most vehemently against this mechanism of installing software, can claim that it is not quick, simple for users, easy to copy/paste out of a web-page, and leaves all the icky complexity of sorting things out up to a script which the computer can run, rather than the nascent user of the software in question. As a result, many varieties of software have ended up using this as a simple installation mechanism, from games to orchestration frameworks - everyone can acknowledge how easy it is to use.

Now, some providers are wising up a little and ensuring that the url you are curling is at least an https:// one. Some even omit the sudo from the copy/paste space and have it in the script, allowing them to display some basic information and prompting the user that this will occur as root before going ahead and elevating. All of these myriad little tweaks to the fundamental idea improve matters but are ultimately just putting lipstick on a fairly sad looking pig.

So, what can be done? Well we (again the OS-development literati) got ourselves into this horrendous mess, so it's up to us to get ourselves back out. We're all too entrenched in our chosen packaging methodologies, processes, and policies, to back out of those; yet we're clearly not properly servicing a non-trivial segment of our userbase. We need to do better. Not everyone who currently honours a curl | sudo bash - is capable of understanding why it's such a bad idea to do so. Some education may reduce that number but it will never eliminate it.

For a long time I advocated a switch to wget && review && sudo ./script approach instead, but the above comment, about people who don't understand why it might be a bad idea, really applies to show how few of those users would even be capable of starting to review a script they downloaded, let alone able to usefully judge for themselves if it is really safe to run. Instead we need something better, something collaborative, something capable of solving the accessibility issues which led to the curl | sudo bash - revolt in the first place.


I don't pretend to know what that solution might be, and I don't pretend to think I might be the one to come up with it, but I can hilight a few things I think we'll need to solve to get there:

  1. Any solution to this problem must be as easy as curl | sudo bash - or easier. This might mean a particular URI format which can have os-specific ways to handle standardised inputs, or it might mean a pervasive tool which does something like that.
  2. Any solution must do its best to securely acquire the content the user actually wanted. This means things like validating SSL certificates, presenting information to the user which a layman stands a chance of evaluating to decide if the content is likely to be what they wanted, and then acting smoothly and cleanly to get that content onto the user's system.
  3. Any solution should not introduce complex file formats or reliance on any particular implementation of a tool. Ideally it would be as easy to implement the solution on FreeBSD in shell, or on Ubuntu as whizzy 3D GUIs written in Haskell. (modulo the pain of working in shell of course)
  4. The solution must be arrived at in a multi-partisan way. For such a mechanism to be as usefully pervasive as curl | sudo bash - as many platforms as possible need to get involved. This means not only Debian, Ubuntu, Fedora and SuSE; but also Arch, FreeBSD, NetBSD, CentOS etc. Maybe even the OpenSolaris/Illumos people need to get involved.

Given the above, no solution can be "just get all the apps developers to learn how to package software for all the OS distributions they want their app to run on" since that way madness lies.

I'm sure there are other minor, and major, requirements on any useful solution but the simple fact of the matter is that until and unless we have something which at least meets the above, we will never be rid of curl | sudo bash - :- just like we can never seem to be rid of that one odd person at the party, noone knows who invited them, and noone wants to tell them to leave because they do fill a needed role, but noone really seems to like.

Until then, let's suck it up and while we might not like it, let's just let people keep on curl | sudo bash -ing until someone gets hurt.


P.S. I hate curl | sudo bash - for the record.

Sometimes recruiters really miss the point... Daniel Silverstone

I get quite a bit of recruitment spam, especially via my LinkedIn profile, but today's Twitter-madness (recruiter scraped my twitter and then contacted me) really took the biscuit. I include my response (stripped of identifying marks) for your amusement:

On Tue, Jun 09, 2015 at 10:30:35 +0000, Silly Recruiter wrote:
> I have come across your profile on various social media platforms today and
> after looking through them I feel you are a good fit for a permanent Java
> Developer Role I have available.

Given that you followed me on Twitter I'm assuming you found a tweet or two in
which I mention how much I hate Java?

> I can see you are currently working at Codethink and was wondering if you
> were considering a change of role?

I am not.

> The role on offer is working as a Java Developer for a company based in
> Manchester. You will be maintaining and enhancing the company's core websites
> whilst using the technologies Java, JavaScript, JSP, Struts, Hibernate XML
> and Grails.

This sounds like one of my worst nightmares.

> Are you interested in hearing more about the role? Please feel free to call
> or email me to discuss it further.

Thanks, but no.

> If not, do you know someone that is interested? We offer a £500 referral fee
> for any candidate that is successful.

I wouldn't inflict that kind of Lovecraftian nightmare of a software stack on
anyone I cared about, sorry.

D.

I then decided to take a look back over my Twitter and see if I could find what might have tripped this. There's some discussion of Minecraft modding but nothing which would suggest JavaScript, JSP, Struts, Hibernate XML or Grails.

Indeed my most recent tweet regarding Java could hardly be construed as positive towards it.

Sigh.

Kimchi Trial 1 - Part 3 - Kimchiguk Daniel Silverstone

Earlier this week I allowed some of my colleagues at work to try the Kimchi and one of them (James) liked it enough to ask for a tub of it just for himself. Being a lovely person I obliged.

My darling Rob decided that what he really wanted was Kimchiguk or Kimchijijae. Being both wonderful and lacking in ingredients, I set to do achieving something.

I read a few recipes, worked out that I lacked critical ingredients and so set about simulating Kimchiguk. I grabbed two and a bit cupfuls of kimchi from the box in the fridge, chopped it up more finely, popped it into a pot along with about a pound of cubed pork belly, two teaspoons of hot pepper flakes, two teaspoons of sugar, and two teaspoons of cornflour. I then topped that off with five cups of water, mixed it up, brought it to the boil and simmered it for 30 minutes. Then I cubed some tofu, popped that in and simmered it for another 10 minutes while some rice cooked. Served in a bowl over rice, my approximation of Kimchiguk turned out pretty well. (Note it fed both of us and there was a serving left over.)

Kimchiguk - Kimchi soup

With a do-over, I'd try harder to get pork shoulder (belly is quite fatty) and given the option I'd wait until I had hot pepper paste because the malty fermented sweetness of hot pepper paste is pretty much impossible to emulate otherwise.

Kimchi Trial 1 - Part 2 Daniel Silverstone

Last night we tried the small amount of 'fresh kimchi' from my epic kimchi making trial.

I marinaded some beef strips in a blended paste of onion, garlic, ginger, and sesame oil for a few hours before frying that up, and serving on rice with stir-fried carrots, leek and spring onion. A little fresh kimchi on the side for flavour.

Delicious dinner

I think the Kimchi was a success. Dearest Rob said that it tasted of Kimchi. The flavours were not very well combined and quite clearly underdeveloped, and the pepper flakes were still a little hard. I expect this to resolve over the next few days as it begins to ferment.

All in all, experiment going well, expect part 3 when I know how it tastes after fermentation begins.

Kimchi Trial 1 - Part 1 Daniel Silverstone

I have spent today making my first ever batch of Kimchi. I have been documenting it in photos as I go, but thought I'd write up what I did so that if anyone else fancies having a go too, we can compare results.

For a start, this recipe is nowhere near "traditional" because I don't have access to certain ingredients such as glutinous rice flour. I'm sure if I searched in many of the asian supermarkets around the city centre I could find it, but I'm lazy so I didn't even try.

I am not writing this up as a traditional recipe because I'm kinda making it up as I go along, with hints from various sources including the great and wonderful Maangchi whose YouTube channel I follow. Observant readers or followers of Maangchi will recognise the recipe as being close to her Easy Kimchi recipe, however since I'm useless, it won't be exact. If this batch turns out okay then I'll write it up as a proper recipe for you to follow.

I started off with three Chinese Leaf cabbages which seemed to be about 1.5kg or so once I'd stripped the less nice outer leaves, cored and chopped them.

Chopped up cabbage

I then soaked and drained the cabbage in cold water...

Soaking cabbage

...before sprinkling a total of one third of a cup of salt over the cabbage and mixing it to distribute the salt.

Salted Cabbage

Then I returned to the cabbage every 30 minutes to re-mix it a total of three times. After the cabbage had been salted for perhaps 1h45m or so, I rinsed it out. Maangchi recommends washing the cabbage three times so that's what I did before setting it out to drain in a colander.

Drained salted cabbage 1h45m later

Maangchi then calls for the creation of a porridge made from sweet rice flour which it turns out is very glutinous. Since I lack the ability to get that flour easily I substituted cornflour which I hope will be okay and then continued as before. One cup of water, one third of a cup of cornflour was heated until it started to bubble and then one sixth of a cup of sugar was added. Stirred throughout, once it went translucent I turned the heat off and proceeded.

Porridge thingy

One half of a red onion, a good thumb (once peeled) of ginger, half a bulb of garlic and one third of a cup of fish sauce went into a mini-zizzer. I then diagonal-chopped about five spring onions, and one leek, before cutting a fair sized carrot into inch long pieces before halving and then thinly slicing it. Maangchi calls for julienned carrots but I am not that patient.

Veggybits

Into the cooled porridge I put two thirds of a cup of korean hot pepper flakes (I have the coarse, but a mix of coarse and fine would possibly be better), the zizzed onion/garlic/ginger/fish mix and the vegetables...

All in the pan

...before mixing that thoroughly with a spatula.

Mixed vegetables

Next came the messy bit (I put latex gloves on, and thoroughly washed my gloved hands for this). Into my largest mixing bowl I put a handful of the drained cabbage into the bowl and a handful of the pepper mix. Thoroughly mixing this before adding another handful of cabbage and pepper mix I repeated until all the cabbage and hot pepper mixed vegetables are well combined. I really got your arms into it, squishing it around, separating the leek somewhat, etc.

Bowl of kimchi

As a final task, I scooped the kimchi into a clicklok type box, pressing it down firmly to try and remove all the air bubbles, before sealing it in for a jolly good fermenting effort. I will have to remove a little tonight for our dinner (beef strips marinated in onion, ginger and garlic, with kimchi on rice) but the rest will then sit to ferment for a bit. Expect a part-2 with the report from tonight's dinner and a part-3 with the results after fermentation.

Box of kimchi


As an aside, I got my hot pepper flakes from Sous Chef who, it turns out, also stock glutinous rice flour -- I may have to get some more from them in the future. (#notsponsored)

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