November 29th, 2015

Yes, this place:


People who follow my car blog will know that’s where I am presently, and will be, for the next 5 months or so. I’ve been here about a month now. I am working at this place:


Weta Workshop.

The story basically goes like this (it’s quite long but this is a big thing!):

I’d just been made redundant from my last job. They ran out of money. Actually, worse than that, they had money pulled out by investors who obviously decided it wasn’t worth the risk. I don’t blame them. The company didn’t know who their potential customers were. That didn’t seem to matter though as they had no sales team to sell it anyway. And the marketing people didn’t seem to do any actual marketing (although once they did ask in company chat if anyone had any idea for cool social networking campaigns).

The product didn’t actually work that well either, being mainly a data store, but with no search functionality. I actually raised that once and was poo-poohed by the CEO, who said in the 5 years they’d been developing it no one had asked for a search function before, and the head of support, who said they didn’t need one since a user could simply go into the module they thought had the entry in it, order all the records by the time entered, then search through page by page (a page displayed 10 or so entries at a time) until you found the one you were looking for. This for a product that is meant to contain a lifetime (and that word is in the name of the company even) worth of data.

I knew the writing was on the wall when they decided to throw everything into making an iOS  app and hired a new team to do it at short notice. But apparently no one had read the Apple Developer guidelines (VERY important if you’re doing an iOS app). Any app sold through the Apple app store is either free or Apple gets a cut. And that cut is 30%.  You also can’t use a free app to lead people to a web app the users can pay for (which seemed to be their plan).

The app also used the Apple watch and made use of voice recognition. It never worked that well and they were trying to get something into the app store when the end came for most of us. Oh, they also made a nice video showing the product in use (faked!) but obviously hadn’t read the Apple guidelines for that either. Hint – if you’re showing Apple Watch functionality you shouldn’t be showing it on non Apple devices like Microsoft Surfaces!

Anyway, the upshot of all this was a bunch of us were given the chance of staying (for less money) or leaving. We had to decide, tell them what we wanted in one on one meetings, then management would decide who would stay and who would go. I’ve been through that before and it’s never a good situation. In my meeting I said I was definitely out, I didn’t even have to think about it.  In the end most of the development team was gone and 2/3rds of the test team leaving only the most junior to carry on. Apparently they would get the others, like support, to help with testing. I’ve seen that before and it always shows what management think of their testers when they say ‘anyone can help with testing’. And all the companies that say that end up failing.

Anyway, I was out and starting to think about a new job. I started putting a few feelers out. Now I.T. pays very well (I am thankful for that) but most of what you do in it is pretty pointless! Products that go no where, companies that fail, it all seems a bit unnecessary really. Makes job hunting hard since you of course have to go along to interviews and pretend you really believe in whatever niche thing the company is selling that they think will change the world (but in reality is just there to make someone money).  I have learnt over the years the most important thing is working somewhere with people and a team you like (and I did like the team at the last place) and actually liking the work you do. It can be hard knowing what either of those are going to be until after you start working there. I actually started interviewing and one place looked interesting, the team seemed good and I had heard good things about them but then this chance came up.

Thankfully since from the above rant it should be obvious I was feeling a bit jaded about the whole I.T. and software testing industry!

I’d just finished my Turing Welchman Bombe project and ended up sending a link of it to Richard Taylor at Weta. He’d previously seen my John Steed Puppet project and I knew he was interesting in things that people make. The CEO at a previous start-up I was at had forwarded him the link to Steed. Funnily enough I left that place to start at the last place and had left shortly before the entire dev/test team were let go from there. I didn’t know that was going to happen and hope no one there thinks I had any prior knowledge! It really was just luck I left when I did.

Anyway, Richard and I started chatting a bit and I mentioned, half jokingly, I was fed up with I.T. and had always thought one day I should apply to him for a job making stuff. I’d actually been on the Weta Cave tour last year and had talked to the guide about how did people get jobs there. They have a lot of people apply I imagine! Anyway making stuff is one of the things I like to do (see projects on the right there) and that’s obviously something they like to see. Richard said I should come to Wellington to see them, as soon as possible, they might have an opening for me.

I was down there in a shot! A slow shot since I took the train (much prefer the train to flying) but it was still all within a few days of our chat. I took Steed with me and had a sort of interview with Richard (you don’t get to take puppets to I.T. interviews although if I go back into it maybe I should try it!) then spent the afternoon looking around the workshop with the animatronics team lead. The next day they offered me a job doing animatronics working on a film project they are doing. I can’t say what it is, what they do is confidential of course, but there should be 5 or 6 months work. The film industry is fickle though and there are no guarantees, this was all explained to me, but for me the risk is minimal. And how could you say no! And I always have I.T. to fall back on.

I was in Wellington for the rest of the week so I started trying to find a place to live. The plan being to lock up my house and garages in Auckland and move here to Wellington for 6 months to see how things go. Everything came together beautifully. I got to see a fully furnished flat on The Terrace (in the middle of Wellington city) on the Saturday and went back to Auckland on Sunday to sort out how I was going to do every thing.  I was due to start at Weta the day after Labour Day, that gave me about a week! I got the flat so worked out what I would need to bring with me and sorted out sending that down. Very few people work for Weta Workshop as permanent employees. Due to the nature of the industry everyone works as an independent contractor. The work can come and go. I needed to provide my own tools (luckily I had nearly everything I needed). Animatronics is a mix of electronics and mechanics and increasingly I  guess, software, so I have everything I need already since those are all things I do for fun. My house I simply shut up, my parents being literally around the corner are looking after it for me. The plan is to try it for 6 months and see what happens!

I flew down, had a few days to settle in and started work! I’ll get to what that’s like in a bit.

First, my little flat. I own my own house in Auckland. It’s not big but it has all my toys, my TARDIS, my dust collection and all manner of other things as well as my two garages where I work on my cars. My new flat is tiny. I call it my Bacgelirvpaf. This is what my phone came up with when I tried texting ‘bachelor pad’ (badly) to my friend Penny and now the word has stuck. Interestingly, if you search for that in Google it doesn’t exist (errr, until the robots find this entry) but the Google auto correct does translate it back to Bachelor Pad. I think I just invented a new word!


My new little bacgelirvpaf is even smaller than my house. It is nice though. It’s in an older building full of small flats. Mine is on the second floor at the back of the building and I have outside access. It’s just three rooms and a small hallway. Kitchen, bathroom and living/bed room. Despite there being parking spaces there is no parking for this flat. So I have no car!


The main room is nice. I have doors so can shut off the kitchen and bathroom. I much prefer that to these modern ‘studio’ apartments where everything is one room really. The windows face west and overlook a small park built on top of the terrace motorway tunnel. It’s surprisingly quiet, I hear the odd noisy car on the motorway, but it’s actually quieter here than my house in Auckland. It’s gets all the afternoon sun and sitting on the bed all I see is the green of the park. It’s very restful!

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It was fully furnished although I had to buy the little table by the window (fold up plastic thing cheap from Bunnings). I bought my signed Steed picture (since Steed got me the job!) and my Brooklands memento I made after last years trip. The kitchen is full of comedy appliances. There is no oven, just a tiny toaster oven and a double hotplate. The fridge is decent thank goodness but the dishwasher and microwave are tiny. I don’t use the dishwasher much. It just doesn’t work well. It’s so small you can barely fit everything then when you do get it in there  it comes out dirty! I don’t have one in Auckland and don’t really like them (dish washing powder is nasty stuff) so I just use the sink! Takes a hell of a lot less time too!

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I bought the worlds tiniest crock-pot (12 dollars from the Warehouse – I got a bargain!)  and can actually make surprisingly good (but small) meals in it in that tiny oven.

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I should point out it doesn’t magically convert beef to chicken and that I only photograph my food in the privacy of my own home, I am not one of those freaks who do it in public! I also discovered you can get tiny gluten free pizza bases so I can make comedy sized pizza too (that was a boring one to see if it would work)!


I am actually eating far less which is probably a good thing. I also get more exercise as I am catching the bus to Miramar and back each day which is where the workshop is. The bus stops are only 5 minutes walk away either end but at the home end I am at nearly the highest part of the terrace which is on a ridge running above the city. There is a walkway down right over the road from the flat which is handy. But there are about 180 steps to travel!


It’s ok going down but coming up after a long day carrying my heavy laptop and shopping is a killer. I call it the Eiger, after The Eiger Sanction, as it will probably kill me. I am enjoying catching the bus again though, mainly because I get to read on it. I joined the library which is less than a 10 minute walk away. It’s one thing I missed when I was working from home, time to read. Public transport is perfect for that.

There was some interesting graffiti on that stairway but it’s gone now.


Wellington itself is a nice city. Very compact in the centre, you can walk everywhere. There is a New World Metro just down the road. Handy but expensive and it can get horrendously busy. There are other New Worlds either end, the one near Te Papa is very good and if needed I can get off the bus near there and walk home. There is also a VERY good fruit and veggie market near there on Sunday mornings.  There is a similar, smaller one, even closer to home.  Excellent quality fruit and veggies at very cheap prices. I get a whole weeks worth of vege and salad stuff for about $10. It does help that a decent stew in my little crock pot consists of only half a potato, half a carrot, half an onion, one small mushroom and what ever meat I want. I make salads for lunches and Weta provide free fruit which is nice.

The weather is odd in Wellington. I am pretty sure the Met service just make up the forecasts randomly.  It’s know for the wind and it can get very windy. If it happens to be raining too it can be a bit unpleasant. Sideways rain! And Wellington is not a place for umbrellas. But when it is a nice, calm day it is actually very nice! It can get chilly but I actually like that. I like hats and scarves and long coats so it actually suits me. I am known for wearing wool vests all though summer.

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The city itself is more relaxed than Auckland. And people make use of it. You see people relaxing all over the place. There are cool streets, good shops, places to sit and a very pleasant waterfront. I’ve lived in Auckland for most of 40 years and just never liked it much. Less so over the years. A few things are improving now. But it’s one of the things I have noticed. It’s a try hard type place. The sort of place where they go on a lot about being one of the world most desirable to live in cities (even those those sort of surveys are all bollocks). They’ll make a lot of noise and song and dance about it. Wellington strikes me as the kind of place that just quietly gets on with things.

It’s not all perfect though. Shops in the city close early and open late in the weekends. A bugger if you work long hours and need to get to some thing like a bank or post office. And I gave up on recycling. Apparently you need special bags from the council to put it out in. I haven’t worked out how to get them. I think what happens is they send them to house holds once a year. But I am in a flat and the previous tenants didn’t leave any or even have any. According to the council web site you can get more from the public libraries. So I asked at the city public library. They don’t have them because they are next door to the council service offices and you can get them there. I asked if they are open in the weekends. Nope, only during the week. And they shut at 5! So I gave up. This building seems to have it’s own collection and everyone else seems to put it in there so I do too. I doubt it’s being recycled though!

I have found people are friendlier here though. In shops especially, people are quite chatty. There are also tons of restaurants and bars and cafes. I am not much of a cafe person really. I don’t see the attraction of going somewhere that’s mad busy to be rushed and jostled and have to shout to talk. Same with pubs. I prefer quieter places these days. Rather just sit in the corner of a quiet pub with a beer and book to be honest! I actually miss The Crap House where I could go have a quiet beer and a moan about I.T. work with Dave and Ralph! I don’t have any drinking buddies here. I avoid Courtney Place (where the young people and tourists go – young girls pretending to be wearing skirts!) and am instead finding all the out of the way places. There are a few of them around.

Wellington does have a lot of small craft breweries. Although it is hard to tell a lot of the beers apart I find. And it is hard to find a good hand pulled pint sometimes. I have found a nice place just down the road that’s hidden a bit that good though. They have a couple of beers on the hand pumps. And I found I can get some Galbraiths bottled beer that the supermarket just down the road!


I haven’t seen too many old cars yet. The oldest is a 1953 Morris Minor that parks on The Terrace sometimes. I did see an MGB on a trip out to Petone once though. Nothing vintage though.


I am slowly settling in. Internet was a mission to get connected. That’s because I am unfortunately with Vodafone and they excel at incompetence. I arranged to have my connection from Ak moved. They said I would have to be home in the flat (why I wondered?) so I arranged for them to come round the same day I was home to take delivery of the things I had sent down. I had to take a day off work for that. I was looking out the window and actually saw the van turn up. The guy never came to the door though. I know that for certain as I was waiting for both him and the delivery men. I figured he’d done something in the building and that was all that he needed.

Next day, no Internet. Interacting with Vodafone support is a nightmare. They are one of these companies who think it is a good idea to offshore their support. I think it’s in the Philippines somewhere. If you are lucky you’ll get connected to someone speaking understandable English. Chances are you won’t. Either way when you do get though you have to go through the whole story with yet another new person every time. And chances are they’ll transfer you to someone else and you have to go through it all again! Eventually I was left the following voice mail.

You can read the rest of the saga in the YouTube description. Eventually it was sorted and luckily it wasn’t cut off. This time I rang back the NZ woman who had helped me sort it out directly and she checked and said it was all fine. Seems to be working now.

I have slowly been sorting out my hobbies. I had to choose what to bring with me. In the end I bought my film cameras (well, only 2 of them) and film developing gear, my microscope and my model making stuff. I had a mission trying to get my film negative scanner working on my laptop. The laptop is running Windows 10 and you just can’t get the scanner to work on it. The manufacturers know this and their suggestion is to just buy their latest scanner which will work even though the hardware is no better. Planned obsolescence, I hate that! In the end I did get it going by using it as a simple web camera with appropriate software (which in reality is all it is).

I have been doing model making. Plastic models and lately a little rubber band powered balsa and tissue one. I made a couple of those as a kid and find it quite relaxing now. I  sit at the window at my little table in the sun and do a little at a time. They are repainting and replacing the carpet in my flat in a month or so and will have to get a big drop cloth I think so there is no danger of dropping things onto new carpet!


I can take the model to the park behind the flat to see if it flies! I haven’t missed the garages too much yet although I would like to be building the Austin engine and starting on the Brooklands. Most of the time I have just been reading and listening to music and relaxing. I have an unlimited broadband connection so I just stream music all the time. Lots of classical stuff.  And watch a lot of films and old documentaries on YouTube. I am actually enjoying the lazy weekends! I miss my big computer a bit. Can’t really play FPS games on my laptop and I used to like a bit of Nazi killing. I have been playing some older adventure games from GOG though which are fun.

Electronics I am doing at work. That’s probably what most people want to know about. What am I doing at Weta and what is it like? I can only actually say so much! What we work on is confidential and you can’t take any photos in the workshop itself (they don’t even allow them on the tour). But I can give some general comments I guess.

In another post!

If you think it must be an amazing place to work, you’d be right!

Turing-Welchman Bombe completed.

October 4th, 2015

Well, it’s finally complete!


Probably what most people want to see is the Bombe in action so here we go.

For those who haven’t been following the whole project basically I reverse engineered then build my own desktop version of the Bletchley Park Bombe, the machine the British used to help solve the Enigma code during WW2.

Thanks again to John Harper, who lead the BP Bombe rebuild team and who answered some questions for me, James Grime, mathematician and Enigma Expert, Magnus Ekhall who was one of people behind the online Bombe simulator, Frank Carter, who wrote the BP Report 4 booklet, and Bletchley Park themselves who managed to find and send me a copy of the aforementioned report that is out of stock! Also the late Tony Sale who made available on his web site the US 6812th Division 1944 Bombe Report.

I started by making my own Enigma machine wristwatch because to understand the Bombe works you have to fully understand how Enigma works and how it was used operationally.


You can read about that here.

My Turing-Welchman Bombe machine makes use of some software I wrote in C++ running on a Raspberry Pi 2. I figured out for myself how the Bombe worked then wrote my own software version, initially in BASIC of all things to run on my homemade 6502 computer Orwell. With the general algorithm worked out I ported it to C++.

The Raspberry Pi 2 connects to an Arduino which then drives three stepper motors, via driver boards, to turn the three indicator drums on the front of the machine. These drums mimic the three indicators on the real Bombe. The Arduino reports back the position of the drums to the Pi as a series of pulses then the Pi can tell the drums when to stop. An LCD screen on the side of the machine mimics the original Bombe mechanical indicator unit as well as providing a basic user interface. Start and Stop button are provided on the front of the machine as on the real Bombe.

The machine runs in real time (although the next stop is pre-calculated) so a Bombe run should take the same amount of time as a real Bombe run at Bletchley Park.

The casing is steel tube brazed together and the panels are 0.8mm sheet steel finished in wrinkle black paint. All the wiring is cable laced together into bundles. The drums are 3/4 scale replicas I made at home from old sweet tins! All the parts for the hubs and drums are hand made with a small lathe and simple hand tools. The drum faces use dry transfer lettering (which is getting hard to find these days – mine came from a model railway shop)! The machine is totally self contained with it’s own power supply (a 12 volt SLA battery) so is portable, although it does weight 10kg.

Menus are loaded onto a USB thumb drive inserted into the back of the machine. I mainly run the same menu as used at BP but it does run other menus such as the test menus in the US Army report. I haven’t been able to get all of them to run though but then I can’t get them all to run on the online simulator either.

All the details of the build, software and so on are in previous posts but are some pictures of the finished thing.

General views:

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Internal details:

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Indicator unit:

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More details:

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I will make the code available to anyone who wants it but it’s not really much use to anyone without the actual unit. If you want to see it to see how my Bombe algorithm works though it’s not too hard to pick out the core functionality. You have to have a VERY good understanding of the Bombe and what it is doing to really understand how it works although the code itself isn’t hard to follow. If you want to see it just ask me. If there is enough interest I can package up the C++ code and the Arduino code (for driving the steppers) and post them here.

Below is an example of how my menu files look:

* This menu is used to demonstrate the recreated Bombe at Bletchley Park.
* This will generate two stops:
* DKX:Q (correct stop)
Rotors: 2, 5, 3
Reflector: B
Test register: G
Input voltage: A
U: 1i
E: 1o, 2i, 7o, 8in
G: 2o, 3i, 11o, 12i
R: 3o, 4i, 10o, 11i 
A: 4o, 5i
S: 5o, 6i, 13o
V: 6o, 7i
N: 8o
H: 9i 
Z: 9o, 10i 
L: 12o
W: 13i

Painting VHT wrinkle finish paint.

September 27th, 2015

This is a follow on from my Turing-Welchman Bombe project and shows how I painted the case panels in wrinkle finish paint. But this paint used in many other places, such as old car instrument panels, so I thought a film of how I do it would be useful.

I am tempted to turn off comments on that as I just know someone will say I am doing it all wrong (with no proof of their better way of course) but that is what works for me.

I am using VHT wrinkle finish paint as that’s the sort I can easily get here in NZ (Repco sells it). I get all the gas from the can then decant the paint out. It is very thin so can be sprayed as it from the gun, no thinning required.


The biggest problem I find is getting an even enough coat of paint. You need about 3 or 4 coats to get a nice, heavy build up but the real trick is getting it even. That is why I put the paint into a proper spray gun since I find it much easier to get a good coating using the gun rather than using the spray cans themselves. In the film I was having a little trouble with the gun (not enough paint in the pot) but even then I managed to get a good coverage. And yes, I nearly dropped it at one point!

You must avoid paint runs! Any runs in the paint will show up as a different, thicker wrinkle in the finished part. You can control the amount of wrinkle by how thick the coat is to some degree. I prefer a lesser wrinkle myself but that’s personal preference. Too thick and I find it look a bit overdone.

To make the paint wrinkle I use a hot air gun. I have a cheap 2000W one from Bunnings (I think I said NZ$30 but it looks like it is $40). I set it on the hottest setting. You just need to keep it moving to avoid burning the paint. Something that also works well is heating the back of a steel panel with wrinkle paint on the front. The other option is to put the piece out in the hot sun. That will work but I find it only works well if the whole piece is evenly illuminated. I get much better control with the air gun.

The paint then needs to be cured. If the piece is small enough I put it in my normal oven. There are some fumes released but I don’t find it too bad. I usually put them in with the oven set to 100C on Bake for an hour. On the can they say 93C for 1 hour but I know my oven temperature control is no where near that accurate the exact setting isn’t too important. Around 100C works.  Then I turn it off and let it cool slowly. If you are doing car engine parts, such as rocker covers, the heat of the engine should be enough to cure the paint. I would still bake those in the oven though as until the paint is baked it will be soft and if you attach the part with the paint uncured your fasteners are likely to ruin the finish.

If I can’t bake it because it is too big to fit in the oven, say a car instrument panel, then I leave them in the sun or a hot place (my metal garage works well in summer) for a week or so to let the paint cure.

I do find even with practice this is a hard thing to get absolutely perfect every time.


Here are a few other projects I have used this paint on:


Enigma Machine Watch


Orwell 6502 Computer


Austin 7 instrument panel.

Turing-Welchman Bombe physical build – part 10.

September 26th, 2015

I really need to start working on projects that don’t need so many bloody posts!

Where was I up to? A lot has been happening but the Bombe is getting close to being done. I finished making the panels for it. On the rear panel I soldered on some brass hinges.


The steel weights stopped the thin metal warping from the soldering heat. To hold the door closed I am going to use a magnet. It works as both the handle and the catch. Nice and simple. I also tried folding up the front panels. The first fold was done on Ian’s pan brake. I had to do the rest at home as there was no way to do the second fold in the brake too.


This worked but I wasn’t happy with how it looked with the side panels wrapping right around the front. In the end I scrapped that idea and instead made new side pieces and separate front pieces. The idea being that then the casing is more symmetrical. Each side has panels only on it’s face and the corners would show up as a feature since the panels are done in wrinkle finish paint but the main case would be smooth. This actually worked really well in the end.

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I then started painting things. The frame is painted in zinc rich primer then finished in a subframe black enamel. I got the paints from the local auto parts shop (guess which one)!

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The black is a hard, satin finish. It goes on rather thick and glossy but it self levels and then dulls down rather nicely.


The panels were painted in wrinkle finish black then baked. I ran out of paint half way through and only just finished the remaining side panel today. Since people seem interested in how to do this wrinkle finish (we use it on vintage cars too) I actually made a film of how I do it. I will do a post on that after this.

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I also made small brackets to hold the volt meter and the battery into the case. They are held in place with the same screws that hold the wheels in place.


Most panels I only painted wrinkle finish on the outside. The insides are painted with the same subframe black as the frame. The bottom panel I wrinkle finished both sides so it would match the wrinkle finish brackets that bolt to it. The coating on the bottom wasn’t very even but as this is the underside of the machine it won’t be seen (unless it falls over)! I then started assembling things.

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I did need to make a small modification to one panel. I made a cutout for the wire to pass through the side panel to the LCD module but I also needed a second one to provide clearance for the connector itself attached to the module.


The new style front panels look great and you can see how they wrap around to the inside of the frame and also how the brown panels help close off any holes.


Most panels are in place now as is the electronics board and the drums. Since I only just painted the remaining side panel today so can’t fit it or the rear panel until the paint is dry and hardened. Even then I can’t fit them as I ran out of 6mm screws and had to order more! That is a worry since there were 100 in the last packet. I have used far more screws than necessary from a mechanical point of view, but just enough from an aesthetic one!

I don’t want to give too much away until I am complete but if you watch my painting film you can see more of the partially finished Bombe there.

I still need to redo the script that starts the Bombe code automatically when the machine powers on. After assembling it I turned it on (making damn sure this time everything was connected correctly!) and was shocked when nothing happened. I had forgotten that it isn’t running automatically yet. I connected to it and SSHed in and ran it manually and everything still works which was a great relief.

Turing-Welchman Bombe physical build – part 9.

September 2nd, 2015

Right, latest progress. The poor Pi was dead so I ordered another (NZ$48 from Farnell as RS didn’t have any). It turns out I had also killed the LCD so I had to order another of those off eBay. That only arrived today. When the new Pi arrived (after only a few days) I had a look at updating my code to the new scheme. I have modified the code (and hardware a little) so that the Pi only tells the Arduino to run or stop. When running the Arduino sends pulses to the Pi for each letter it passes and the Pi then tells it to stop at the right place. It knows where this is because I can cheat a little. Since it only takes 12 seconds or so to do a full run on the Pi I have it calculate ahead before the drums even start turning. It calculates to the first stop then waits. As it waits it counts pulses from the Arduino. When the Arduino has passed the right number of letters  the Pi says stop! It then starts calculating to the next stop so when the user starts the machine running again it already knows where it must stop next time. This all works very well and the movement of the drums is now nice and smooth.

I got all this working but another problem appeared. On startup, for some reason over 3 amps was being drawn and my power supply voltage  would drop (it’s only a 30V 3A) supply and the machine wouldn’t start. In the end I worked out the issue was the little boost converter I was using which couldn’t handle the initial start up current peak. I decided to replace the power supply section with a new one using an LM1085 LDO regulator ordered from RS. I remember, back in the day when I was still at school, getting copies of the massive RS catalogue and drooling over all the parts (all pre Internet of course). They were hugely expensive back then. Now they are brilliant. Lots of parts, reasonable prices and free shipping! Even for two measly LDOs (I only used one in the Bombe). Anyway, I made a new power supply board and that solved the issue. Current drawn now is much lower and nowhere near 3 amps. When running it’s more around 1.5A.


I then decided to tidy up my code, especially my button handling. This is where I made another stupid mistake. I messed up in my button handling code. The program would start running then mistakenly detect a button press causing it to exit with a shut down code. Normally this wouldn’t be a problem. Unfortunately I still had the Pi running the code automatically on startup from a script that would shut down the Pi on seeing the program exit with the shut down code. This meant I got stuck in a boot up, run then immediately shut down loop! The thing would shut down well before I could even connect to the Pi to try to break the cycle.

I tried all kinds of things to figure out a way around this. If I was a Linux guy I probably could have figured it out somehow. I did play a bit with live Linux boots and so on to see if I could get onto the SD card from the Pi and into the file system itself but to no avail. The img on the card is special somehow and I could never seem to mount it or get into it successfully.  In the end I gave up and had to reinstall the Pi from scratch.

That’s not too big a deal except I got caught out once again by the bug in the Wiring Pi library that means if you have an LCD with more than 20 columns it simply exits the code with no errors. Took me a while to remember that one. A quick code change in the Wiring Pi library and a recompile fixes that.

I still need to make the code auto run but I have learnt my lesson and won’t do that until I know for certain it all works! I still want to do more testing on it but it is all running very well now I think. The running is smooth and the stepping is very accurate. I did slow my Bombe down ever so slightly and that helps. So it is a little slower than the Bletchley Park Bombe but that runs a little fast compared to the original Bombe. Either way a run takes around 20 minutes so a few seconds difference doesn’t matter.

I’ve also done the metal work for the indicator unit. Since the LCD was dead I was able to take it to the shed to use when bashing steel about for sizing and so on without worrying about it. The steel housing is made in two pieces soldered together. I made a cardboard template to start with to make sure it was going to work then it was simple metalwork to make the cover.

IMG_4329_1 IMG_4330_1

IMG_4331_1 IMG_4333_1

Metalwork is sometimes a lot like being a Womble. You have to make good use of the things that you find. Bits of steel, tools, wood, bench edges, clamps, vices and so on. All useful for shaping metal.

IMG_4334_1 IMG_4335_1

IMG_4338_1 IMG_4339_1

I soldered threaded standoffs into the housing to attach the LCD to. And of course painted it all crackle black.

IMG_4341_1 IMG_4344_1

Today I received (as well as the new LCD) some more steel. 24 pieces of 0.8mm Zintec offcuts off TradeMe. So I started making the side panels and actually remade the top also. I have marked out and cut out the sheets and just need to fold them, drill them and make the various openings and panels in them.

IMG_4350_1 IMG_4351_1

Tomorrow I am off to see a man who makes vintage Alfa Romeos and hopefully popping in to Ian’s on the way. I think he has a large pan brake (a sheet metal folder) so hopefully I can borrow that quickly to make the first folds. The rest I will do on the frame itself so everything fits well.

Am getting closer to completion!

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