Halloween Fun – A Spooky Ghoul-in-a-Box!

So it’s that time of year again. The UK seems to have become more upbeat about Halloween in the last few years, certainly a difference from my youth when trick or treating was distinctly frowned upon! We always get lots of little horrors dropping by so we have a big bowl of treats waiting – along with a little surprise.

You may have seen the ‘Pumpkin Pi’ I made last year, this was a complete hoot and worked very successfully.

This year I thought I’d try something different – and a little more animated! I like the ultrasonic sensor that the Pumpkin Pi uses, it’s really easy to set up and there are loads of resources online – Python is my favourite flavour and it’s really easy to set up simple distance measuring with the sensor which can lead to all sorts of Hocus Pocus.

The initial thought was, I want something hidden that can jump out of a box with a ghastly scream. Achieving that took a fun afternoon of hackery and a lot of bits and pieces I had lying around.

So, to build a motion-sensing-ghoul-in-a-box I used the following recipe:

1 garden fence trellis

1 bicycle inner tube

Lots of scrap wood

Lots of glue, staples, tape and wishful thinking.

1 Raspberry Pi

1 Ultrasonic Sensor

1 mask (35p from Tesco!)

1 box

Making the base…

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I saw the trellis in the back of the shed and knew that it would be perfect. Getting enough spring for it to ‘jump’ quickly and effectively was going to be tricky. I looked at elastic bands and the few springs I have lying around and none was going to have enough oomph. I’d seen some really powerful catapults made using tyre inner tubes so I found an old one with a puncture and re-purposed this.

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I stapled the sliced up tube to the trellis and then attached them to the frame like this..

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Then added a small screw as a latch to hold it down under tension (you can’t see the screw in this picture – but you can see it holds it nicely!

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Then it was time to go inside and put together the electronics. This was quite straightforward, I set up the sensor and the Python code to measure the distance. I then took a relay board I designed for sHazBot, my PiWars robot and used this to turn a motor backwards and forwards rapidly to act as a ‘trigger’ Releasing something held under load can be tricky but this method works very well.

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I 3D printed a little cam to push against the trellis and release the spring…

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Time to put it all in the box – added a speaker to play some horrible screams, and a battery so it can all run headless (how appropriate) and it all fitted in nicely.

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Finally I added a *really scary* (?!) mask that cost the grand sum of 35p! I also added LEDs to the eyes for extra effect.

Spooky Ghoul-in-a-box – primed and ready!

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I think the end result works really well, think I’ll be leaving this out on our front drive on Monday to welcome any callers who may happen to pass by!

The video is a bit dark and best viewed in a dark room. But hey, it’s a horror movie! It’s also a LOT louder when you’re standing next to it (I turned it up to 11)

(No ghouls were harmed in the making of this video.)

Have a terrifyingly happy Halloween everyone!

Until next time..

DP.

 

 

 

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Jack of all trades, Master of Computer Science – and now a PhD. student!

moi

This is Jester Coder, my little mascot, standing on the little computer that could. And the one that’s made this journey possible. As many of you who follow me on Twitter already know I was a fairly lousy student in a fairly lousy school. I always used to joke that double ‘not-getting-stabbed’ on a Wednesday afternoon (also known as German) was by far my favourite lesson. There was, however, one dedicated teacher (thanks Mr Glazier) who instilled in me a passion for coding and computing that never left me. Sadly circumstance meant going to University was not an option at the time so I left with almost no qualifications and no idea what I was going to do.

I’ve always worked for companies doing generally techy things, but always in sales or management. Fast forward 20yrs and several life-times and in 2012 and I was one of the first in the queue for this new little wunderkind called a Raspberry Pi. If I’m honest, I actually did very little with it. I’d never touched Linux or Python and really had little idea what I was doing. I did a little experimenting but it wasn’t until a visit to Bletchley Park and The National Museum of Computing a few months later where I saw adverts for something called a Pi Jam (or Raspberry Jam) which piqued my interest no end.

I returned less than a week later to the next Jam where I met Mike Horne, the now esteemed PiWars organiser, PiPod Podcaster, and Cambridge Jam Organiser. I also met Peter Onions, another famous Pi-Face. Some of the projects on display blew me away and I couldn’t help but think I’d missed a trick with this little device. So, I worked through ‘Invent with Python’ by Al Sweigart – highly recommended, via ‘Learn Python the Hard Way’ – also excellent, and eventually worked my way up to doing a MOOC with Rice University (An introduction to interactive programming in Python.)

3 years and many projects later I was lucky enough, based on the work I had done with the Pi and my self taught experience, to be accepted to read for a Masters in Computer Science at the University of Hertfordshire. I am thrilled to report that I received the final grade for my dissertation today and I got a distinction for this, which happily guarantees me a distinction for the MSc. overall.

With that in the bag I can now reveal that I have been awarded a fully funded PhD. studentship with The Knowledge Media Institute. This is a part of the Open University and is based, rather perfectly just down the road from Bletchley Park where this journey really began. I will be studying full time for three years – and they even pay me to do it which is unbelievable. I would never have thought four years ago that this would ever be in the realms of possibility.

I cannot give enough thanks to my wife, to Raspberry Pi, and to the Pi community and all those who encouraged me to pursue that which I have always wanted to.

I was a part of the 8-bit generation, and I still missed out. The Raspberry Pi is a phenomenal success and I believe is vitally important in the growth of interest in CS and STEM subjects for the next generation of coders, hackers and engineers. Long may it continue. I for one would be in a very different place without it.

Until next time.

DP.

 

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