c4di Hardware Group Monster Meetup


Actually we didn't have any monsters turn up. But we did have a lot of people. Hayden was running a soldering masterclass. I was talking about Hull Pixelbots to a whole bunch of students who turned up to find out what we're about. Brian showed off a work in progress which simulates Hull Pixelbot movements in a nifty Python program. And we did some work with one of our youngest attendees, who's trying to make a remote controlled missile launcher (but only a small one).

We were playing with these super-cheap wireless devices. Connect a transmitter to an output pin on an Arduino, wiggle the pin up and down, and the receiver will wiggle an output up and down at the same time. So you can send messages wirelessly from one Arduino to another.

In the past I've not had much success with these, but we tried the RadioHead library and it seems to work rather well, We're going to look into adding a carefully crafted antenna to try and improve the range. And have a look at other wireless options too. 

It was great fun. If you fancy coming along,  the next one is on the 1st of March starting at 6:00 in c4di. 

"The Culture" is really good

You've got to be pretty sure of yourself to allow someone to write a farce about what you're doing. Or brave. Or something. But the Hull City of Culture team did it. "The Culture" is a behind the scenes look at just what goes on in the offices behind those fancy slogans and artistic happenings. There are some lovely nods to the buzzwords and whatnot that come with organising something like Hull City of Culture, but all credit to the team for letting it all happen. And hats off to Martin Green, the head honcho of City of Culture, who actually turned up to take part in the performance that we saw. 

 "The Culture" is a proper farce. Double meanings, mistaken identity, hiding in cupboards, bawdy bits, the lot. It also has a genuine, beating heart at the centre. The cast do a great job of bringing the play to life. Their energy never flagged from start to end. And it wasn't until right at the end, when I wondered where some of the actors had got to for the curtain call, that I worked out just how many roles each cast member played. 

I'm not sure if you'll be able to get tickets to see it before it finishes its run, but if you can, I think you'll have a really good time.

Dear Visual Studio People....


...when I try to edit a program that is running (something which I do rather a lot these days - I think it's because I'm getting old) I get this "helpful" message.

It would be even more helpful if the dialog contained another button I could press to stop the application and return me to the code that I'm trying to edit. 


It turns out that this has already been requested on UserVoice. If you go here you can upvote it. Please do. I'd love to see the feature.

Kickstart Hull's Smart City - free event Wed. 21st Feb

On 21st of February we'll be Kickstarting Hull's Smart City at the c4di. You're invited. You're especially invited if you're a developer wanting to get into city wide networking, a student looking for a new field to get your teeth into or someone who wants to do some good with technology. 

We'll be describing our plans for building a community to work with the latest low powered networking technology and use it to build solutions for local people. It's going to be great fun. 

The event is free, we'll have lots of expertise and maybe even biscuits. You can sign up here

An expert in PLINQ for a day


One of the nice things about writing a book is that you become an expert on a subject (albeit in my case, just for a very short time). At the moment I know exactly how to make different parts of a Parallel Language Integrated Query (PLINQ) expression sequential so that the order of the output set is the one that you want. 

Not many people can say this.  (Oh, and PLINQ is a very neat technology by the way). 

Arduino Retro Computer

Derek put me onto this. It's a retro computer made from two Arduino devices, one of which generates VGA output. Many years ago I discovered that people were using PIC devices to produce video output, this does something similar with an Arduino to generate VGA video. It uses a tiny interpreted basic that is not a million miles away from my HullOS software, although the Basic implementation uses a lot more gotos....

Using the StopWatch class properly

Most people don't really care about the speed that their programs run at. Unless they run too slow of course. 

However, if really do want to know timings, C# provides a rather useful StopWatch class in the System.Diagnostics namespace that you can use to measure the time it takes your program to do something. You use it like this:

Stopwatch stopwatch = new Stopwatch();
// Do something that takes a while
Console.Error.WriteLine("It took: " + stopwatch.ElapsedMilliseconds);

It is especially useful if you're trying to re-write a program so that it uses parallel processing, and you want to find out how long things take to complete. Parallel programming is where your code makes use of all the processors in your computer, not just one of them. It should be faster. 

I'm writing some stuff about parallel features in C# at the moment. For a book that I might have mentioned. So I wrote two versions of the code and then discovered, to my dismay, that the one I'd carefully optimised actually seemed to run slower than the original. I know that for small data sets a parallel solution might not be worth the effort of setting up all the parallel gubbins, and I also know that if there are any shared variables that the parallel code ends up fighting over, this can impact on speed, but whatever I did, the parallel version always took at least as long as the original. Wah. Took me a little while to find the mistake. Here's my code:

Stopwatch stopwatch = new Stopwatch();
// Do single threaded version
Console.Error.WriteLine("It took: " + stopwatch.ElapsedMilliseconds);
// Do parallel version
Console.Error.WriteLine("It took: " + stopwatch.ElapsedMilliseconds);

The parallel version always, always takes longer than the serial version. Have you found the mistake yet?

Turns out that stopping and starting a stopwatch doesn't reset it. So the time for the parallel version is added onto the time for the original. And I'm an idiot. The method: 


- resets the stopwatch and starts it, so that my second operation is timed correctly. I'm now getting sensible speedups, which is nice...

I'm writing a new book

Last year I wrote a book about Python. This year I'm doing another about C#. It's an exam text for the 70-483 Programming in C# Microsoft Certified Professional exam. 

The Amazon site says, rather optimistically, that the book will be in the shops at the end of April this year. I'm fairly sure that it will be a little bit later than that.

But it will be well worth waiting for. 

Super Duper Hardware Meetup

Hullpixelbot Connections.png

We had a really good hardware meetup today at c4di. A whole bunch of new members turned up. along with a bunch of "regulars".

I did a talk about the latest developments on the Hull Pixelbot front. The system that controls the Hull Pixelbot has been renamed "HullOS" for marketing reasons, and is now available on GitHub. There's also a manual for the new scripting language supported by HullOS and an editor program you can use to create HullOS scripts and load them into the robot. 

Finally, I've added the DXF files for laser cutting Hull Pixelbot chassis components, along with STL files for the 3D printed parts that you need as well.

I'll be adding more Hull Pixelbot stuff in blog posts over the next few weeks. 

There were lots of really interesting conversations going on all round the room, which was great. We've still got room for more though, the next meetup is on the 15th of February. You can sign up here

Bank with Monzo


I'm not sure if Monzo is the "bank of the future". But I am sure that it provides a bunch of features that people are going to want in their future banks. Once you've used it for a while you start to think "Why can all banks be like this?".

Banks and their mobile phone apps have been getting steadily better over the years. We can now send money instantly and check our balances. But the balances always tend to lag between "real life" as payments and credits take their time to meander through the banking system. Monzo isn't like that. Within seconds of paying for something with my Monzo card my watch goes buzz and tells me how much I've spent.

The app keeps track of how much I've spent each day, and it knows the retailers I use, their location and the kinds of things they sell. So I can see how much I spend on coffee, petrol and groceries and do (or at least attempt to do) sensible budget type things. 

The customer support is excellent and registering for an account was a snap (quite literally - as you have to record a 5 second video of yourself asking for an account as part of the process).

To add a bit of icing to the already nice cake, it turns out that you can use your Monzo card abroad without paying any of those nasty commissions that other card companies like add on top. It's actually based on Master Card technology, which means that it should work most everywhere.

At the moment you could't really call Monzo a "proper bank account". It's missing a few features that make it a bit hard to use as the only place you put your money. I'm using it by transferring lumps of cash from my main account into Monzo, and then using the Monzo card to spend it. This works very well though, the transactions go through very quickly, so tracking how much cash you left is very easy. 

Monzo have big ambitions to challenge the high street banks, and they are adding features on a regular basis. What they're offering is a big step forward on what is currently offered by everyone else, I just hope they can find a business model that allows them to fund what they are delivering on a long term basis. Speaking personally, I'd be happy to pay a subscription to them just for the improved budgeting tools. I'm sure that all the other banks are looking very carefully at what Monzo are doing, and taking notes.  Banking just got interesting.

You can sign up for a Monzo card here, although there is a bit of a waiting list. Existing account holders are occasionally sent "Golden Tickets" which they can pass on to their chums to get them on the system, so if you fancy having a go, just find someone with a bright pink card, and ask them for an invite. 

Hull Pixelbots at Global Gamejam

The them of the Global Gamejam was "transmission". Over in the university we had a bunch of teams exploring different aspects of this in lots of creative ways. 

I had a bunch of Hull Pixelbots and a newly minted web editor that mostly worked. 

Above you can see a nearly working display of Hull Pixelbots propagating a transmission from one to the other. Each robot is programmed via a web site using a scripting language that runs inside the robot. 

The idea is that each robot "wakes up" the next one by moving close to it. The first attempt fails because the Mr White doesn't wake up Crystal Maisie,, and the second attempt shows my bad planning, in that it leaves Crystal Maisie in the way of the final move from The See Through Kid. Oh well. 

Hopefully players of the completed game will be better at it than I was.  I think it would be interesting for a large team, with each team member controlling a robot and a prize for the fastest transition from one end to the other, using all the robots at their assigned starting positions. I took some pictures during the judging, you can find all of the shots here


Thanks to Simon and David from the university for organising such a great event. 

Hull Raspberry Pi Jam and Hull Pixelbots


Sorry the image above is a bit blurry. My lovely Fuji camera takes fantastic pictures, but only if you're patient enough to let it finish focusing before you take the shot.

Anyhoo, We had great fun at the Raspberry Pi Jam in the Central Library in Hull today. I've written before about how any carefully designed user interface never survives contact with the user. Same happened to day when I turned some kids lose writing little programs to control robots. 

The good news is that making robots do what you tell them was sufficiently intriguing for folks to ride over issues with the interface, and everyone had great fun in the end. I left the event determined to get enough robots together to allow people to do some proper co-operative (or competitive) action.  And set up something rather interesting. 

Then it was on to the Global Gamejam event at the university. The theme of the competition is "Transmission". I've got a plan for that. Involving robots.