I've got some business cards!

I've been to several events of various natures now (like the Hardware Meetup), and at each one I've found that a 'business card' or two would be really handy to give to people so that they can remember the address of this website.

After fiddling with the design over about a week I (and Mythdael!) came up with the design you see above. Personally, I'm really pleased with them, so I decided to post here to show them off :-)

I'm finding that it's a rather good idea to promote and build your brand at these kind of events by showing people the cool things that you've created and learnt, and business cards seem to be just the thing that helps you do it.

My robot works!

I went to the hardware meetup again today. For the last 2 times I've either managed to forget or I've been on holiday (probably both...), but I remembered this time around and I decided to go. I'm glad I did, because, with Rob's help I fixed my robot! It is now trundling around on the floor quite happily :D

The problem was that I assumed that the digital pin numbers on the wemos D1 R2 were the same as the GPIO pin numbers, which isn't the case apparently. Here's a table:

Digital	GPIO
D0	GPIO 16
D1	GPIO 5
D2	GPIO 4
D3	GPIO 0
D4	GPIO 2
D5	GPIO 14
D6	GPIO 12
D7	GPIO 13
D8	GPIO 15

(Table from wemos.cc)

Very odd numbering. It's rather frustrating actually! Anyway, there seemed to be quite a lot more people there this time as compared to last time - it looks like the idea is taking off, which I'm very glad about :-)

If you're in the Hull area and interested in hardware, you should seriously consider coming along. There's a page on meetup.com that contains the details of the next meetup, but the general rule of thumb is that it happens at C4DI every first and third Thursday of every month at 6pm - 8pm.

Before I forget, I'm going to end this post off by posting the modified version of Rob's hull pixelbot dance code that works on the Wemos:

(Git Repo, Raw)

I built a robot!

The day before yesterday we had another hardware meetup at C4DI, and I built a robot! Now I just have to figure out how to program it...

It's one of Rob Miles' Hull Pixel Bots, with a Wemos D1 R2 on the top and two stepper motors and their driver boards mounted in the middle, and a battery box on the bottom.

The wheels are a little wonky, but we'll sort that out next time :) For now, I'm going to have some fun making it run around on the floor :D

The Hull Pixelbot Meetup

(Above: Rob's WiFi-enabled Pixelbot.)

Today Rob Miles was kind enough to give me a lift to the monthly hardware (or hull pixel bot) meetup. It was different to what I'm used to, but it was rather fun actually!

Rob Miles has built a kit that gives you the parts to build your very own Arduino-powered robot that trundles around on the floor. He's also managed to add a WiFi chip to it too - so you can (provided you write the code) connect to your pixel bot and control it remotely!

You can build your own by going to hullpixelbot.com.

I'll certainly be playing around with it and attending the next meetup (meetups are on the first Thursday of every month at 6:00pm at C4DI).

Portfolios are important

Attending the Game Development conference for students at Hull University gave me a little bit more of an idea as to what companies are looking for in perspective graduates (and more importantly interns in my case) that they are thinking of hiring. The thing that came across to me as the most important is the idea of an up to date portfolio. If you haven't come across one of these before, a portfolio is basically a showcase of everything that you've done, presented in a manner that is pleasing to the eye.

In my case my portfolio is my website, so I've just been spending half an hour or so updating it to reflect my current projects and accounts (I've opened an account on Codepen). You should do this too, and if you haven't got a portfolio set up, you can create one for free with Github Pages. If you're feeling particularly adventurous, you could also create a blog using Jekyll - Github pages supports this too, and it lets you create blog posts as markdown documents (like I do for this blog, although I wrote my blog engine myself), and it automatically transforms them into a blog post on your website for you. You can even use the Github web interface to do everything here!

If you comment below or get in touch with me in some other manner, I might feature a selection here on this blog.

Learning Prolog: Lab Session #6 - More Looping

Before I get into today's post, I wanted to include a picture of some firework that I managed to photograph a few days ago on my phone. A heard them outside and when I took a look out of the window, this is what I saw!

Anyway, Today's Prolog lab session was about more loops. These loops are different to the failure driven loops that we did last time though in that they are recursive instead. Here's an example:

loopa :-
    write('Enter \'end.\' to exit.'), nl,
    read(Input), (Input = end ; loopa).

The above is a simple rule that keeps asking for user input until the user enters 'end'.

?- loopa.
Enter 'end.' to exit.
|: hello.
Enter 'end.' to exit.
|: cheese.
Enter 'end.' to exit.
|: end.
true.

This is done through the semi colon, which acts as an or operator. Although this works, it isn't very readable. Let's try something else.

% Stopping condition
loopb(end).
% Main loop
loopb(Input) :-
    write('Enter \'end.\' to exit.'),
    read(Input2),
    loopb(Input2).

% Starter rule
go :-
    loopb(something).

Much better. The above is divided up into the stopping condition (i.e. when the user types end), the main loop, and a rule that kicks the rest of the program off. When go is called, we call loopb with something as a parameter immediately. Since this doesn't match the fact loob(end), Prolog looks at the rule we defined, loopb(Input). Then it asks the user for input, and starts the process over again until the user inputs end.

Here's an example of the above in action:

?- go.
Enter 'end.' to exit.gdsfgdrt.
Enter 'end.' to exit.sdfgsdgf.
Enter 'end.' to exit.sdfgsdfgertr.
Enter 'end.' to exit.cheese.
Enter 'end.' to exit.end.
true.

Having learnt this, one of the challenges was to write a rule in Prolog. A factorial is where you multiply an integer by all the integers greater than 0 but less than the integer. For example, 4! (4 factorial) is 4x3x2x1, which is 24). Here's what I came up with:

factorial(1, 1).
factorial(N, Factorial) :-
    N2 is N - 1,
    factorial(N2, Ans),
    Factorial is N * Ans.

And here's an example of the above in action:

?- factorial(6, Answer).
Answer = 720 .

That concludes this post on the 6th Prolog lab session. If you don't understand something (or I've made a mistake!) please post a comment below and I'll do my best to help you. Also, if you have any, post your firework pictures below. I'd be interested to see them!