Category: Making

The finished monster

Crumble Monster

A couple of weeks ago I spent my Saturday morning at Brighton Mini Maker Faire. My 6-year old daughter has shown an interest in technology and digital making so we thought she might be keen to see what was going on and have a go at some of the activities that were on offer. We had a great time doing stuff like exploring conductive paintlearning to solder, and chatting to the very friendly inventors of a new and intriguing computer called Ada, designed for young digital makers.

My daughter and I were also both really pleased to meet the inventor of the Crumble micro controller. I first heard about Crumble when said daughter got to use one at school. Here’s a short video intro…

I took the chance to buy a Crumble Starter Kit directly from the very lovely Mr Crumble himself. You can see what you get in the photo below. There’s a Crumble, two ‘Sparkles’ (more on these below), a set of 10 croc leads, a USB cable and a battery box (batteries not included). This kit cost £19.80 which I think it pretty good value.

Photo of Crumble Starter Kit
Here’s what you get in the Crumble Starter Kit (£19.80)

My plan was to use the Crumble to build on the enthusiasm that my daughter had already shown for electronics and programming and it wasn’t long before we got a chance to open the kit and start planning our first project together. Well… to be honest I’d already opened the kit and I’d tried to think of a simple project that we could work on together using pretty much just the contents of the starter kit.

Flashing monster eyes

The first idea that popped into my head was to create a pair of flashing monster eyes using the two Sparkles from the kit. The Sparkles are special LEDs. As well as being able to turn these on and off you can program them to change colour. My daughter is a big Scooby Doo fan so I was hoping I could find a good picture of a monster from the original series (I’m sure there was at least one with flashing eyes) but in the end I just grabbed a line drawing of what I think is supposed to be that character from Monsters Inc. I had this already printed out for when my daughter got home from school, having promised her a session in the InventingLab (aka my office).

Choose your own monster face
Choose your own monster face

Crumble software

The first thing we did together was to download the software that enables you to write programs that run on the Crumble. If you are familiar with visual programming software like Scratch or Blockly then you won’t have any trouble getting started with the Crumble app – it is really intuitive for users of all ages providing they can read the text labels. There are currently versions for Windows and Mac and there is a Linux/Raspberry Pi app on the way.

Hooking up a Sparkle and writing our first program

Once we’d installed the software (this was a great opportunity for me to explain a bit about installing software) we hooked up the Crumble via the included USB cable and connected a Sparkle to it along with the battery pack (needed to power the connected devices). We then wrote a very simple program together to turn the Sparkle on and off. It’s surprising how much fun a 6-year old can get from something so simple and even her old dad found it quite fun. Once we’d got that working we worked out together how to make the Sparkle change colour as well as flash and added a ‘loop forever’ block to make it… well… you get the idea.

Testing out the sparkles
Testing out the Sparkles

Connecting up the Sparkles and the battery pack using the croc leads is pretty easy although little fingers can find the crocodile clips a bit tricky to manipulate. One great thing about the Crumble is that your programs are sent to the board almost the instant you run them and once the program is running you can disconnect the USB cable and just run the program with power from the battery pack. This means it is easy to take your Crumble projects into places far away from a PC.

Making the monster face

We stuck the monster face printout onto a piece of cardboard from the recycling box to give it a bit more rigidity and made holes in the centre of each eye using an old pen.

Making eye holes
Make holes for your monster eyes

Connecting up the two Sparkles

As we’d already got one of the Sparkles connected to our Crumble we stuck this on the back of the face using sticky tape, carefully lining up the LED so that it would shine directly through one of the eye holes.

Connecting first sparkle
Connect up your first Sparkle and tape it to the back of your monster face

Connecting the second Sparkle proved a little more tricky and we had to carefully consult the excellent Getting Started Guide to help us do this correctly. We didn’t get this right the first time as we hadn’t realised the significance of the little ‘D’ and arrows on the Sparkles which show the direction that the current needs to flow when chaining them together.

Getting Started guide
Use the excellent Getting Started Guide to help you connect your Sparkles correctly

It is possible to chain as many as 32 Sparkles together! If you don’t have enough croc leads to do that (and I shouldn’t think many people do) then you can buy Sparkle batons – strips of 8 connected Sparkles – which will significantly reduce the number of croc leads required to create impressive LED arrays. A really great feature of the Sparkles is that even when they are chained together you can still address each individual Sparkle in your program. This means that you can for instance change the colour of each one independently.

Connecting more crocodile clips
Carefully connect croc leads to make the connection to your second Sparkle

Once we’d got both Sparkles taped in place over the eye holes we then taped the Crumble itself to the cardboard side of our monster face. We decided against attempting to stick the battery pack on as well as its quite heavy but stronger tape or maybe a glue gun would sort that.

Taping Crumble on
Tape your Crumble to the back of your monster face

The last step was to colour in the monster face. We probably should have done that before sticking all the stuff to the back but we managed anyway. We set our flashing eyes program running, disconnected the Crumble from the USB cable and took our monster downstairs to show a very impressed Mummy. Watch the video below to see the finished product :)