Author Archive | Helen Roberts

Crafty Crumble Creations: A “police” helmet.

Whenever our 2-year-old finds something with a flashing light on it, he holds it on top of his head and runs around shouting “nee-nah nee-nah”. I decided we would make a flashing helmet, using a variable to set the Sparkle colour and brightness in the Crumble Software.

We used:IMG_9210

  • 1 laptop with Crumble software installed
  • Crumble controller & Sparkle
  • 1 battery box with croc-clip attachments; 3 AA batteries
  • Croc-leads and a micro-USB cable
  • A switch/Switch Crumb
  • Plastic dome; glue; tissue paper; blue paint; cardboard; & sellotape

Connecting the Crumble

Screen Shot 2015-05-18 at 16.49.34This diagram shows one way of wiring up a Crumble, battery box and switch. The switch is connected to Pad “A” on the Crumble and to the +ve terminal of the battery box. By default, the input pads are at zero Volts (“low”). When they are connected to the batteries they receive 5 Volts (“high”).

In this case, when the switch is pressed, input A is connected to the batteries. In the software, therefore, we can use the “Wait until A is Hi” block to tell the Crumble what to do when the switch is pressed.

The croc-leads on the right-hand-side of the Crumble connect to a Sparkle (see previous blog posts)

IMG_9053The photo, left, shows the Crumble and Sparkle connected with a standard push-to-make switch. There are a couple of problems with this set up, though. Firstly, 2 IMG_9056croc-clips have to connect to the top-left “power-in” pad on the Crumble. Also, the tips of the two croc-clips connected to the switch are very close (see right) and can easily short-circuit.

IMG_9061A tidier soloution is to use a Switch Crumb (the one pictured is designed and sold by 4tronix ). This has pass-through power lines, like the Sparkles, meaning it can be connected in line with the battery box and the Crumble.

A pad at the bottom of the Crumb connects to an input on the Crumble (the yellow wire in the picture), in this case to Input A.

Programming the Crumble

Screen Shot 2015-05-18 at 15.25.18Within each Sparkle there are actually 3 LEDs: red, blue & green. Their relative brightnesses are varied to create any colour from the visible spectrum. The RGB Sparkle block (below) allows us to precisely control the colour, by setting each of the LEDs to a value between 0 (off) and 255 (maximum brightness). In this program we keep red and green at 0, only changing the blue.Screen Shot 2015-09-19 at 08.37.25


The Crumble program used is shown above. It continuously checks to see if Input A is high (i.e. if the switch has been pressed). When it is, a loop is executed five times. This gradually increases the brightness of the blue LED within the Sparkle then decreases it (by incrementing the variable “t” from 0 to 200 then decrementing back to 0).

Constructing the HelmetIMG_9191



The plastic dome came from a supermarket package of profiteroles. A hole was cut in the top so the lid of a fabric softener bottle could be inserted. We glued bits of torn tissue paper all over the plastic (a la CBeebies “Mr Maker”) so that it could be painted blue.

The Sparkle was positioned so that it shone up into the the bottle top and the rest of the electronics was sellotapIMG_9205ed into the dome then covered with a circle of card, leaving the switch exposed.

I was planning to construct some sort of headband, attached to the bottom of the dome, with the switch mounted on it like a badge. The two-year-old, though, had already decided we were done. After that, he was never still enough for me to take a better photo than this (see right), so I think I can claim the project was a success!

DISCLAIMER: Clearly this is not a “toy” that would pass any of the safety tests required to make it suitable for under-threes.  The construction of the helmet was an afternoon distraction and our child was closely supervised at all times.

Crafty Crumble Creations: A flashing Christmas tree


In this project conductive thread was used to connect a chain of Sparkles together. This meant we ended up with far fewer trailing wires and bulky crocodile clips.

We used:

  • 1 laptop with Crumble software installed
  • 1 Crumble controller & 5 Sparkles
  • 1 battery box with croc-clip attachments; 3 AA batteries
  • 3 croc-leads (red, black & green); 1 micro-USB cable
  • A piece of evenweave fabric
  • Red embroidery cotton & tapestry needle
  • Conductive thread (available from Mindsets )
  • Green sticky-backed felt, glitter glue & stickers

IMG_7849 First the Sparkles were tacked onto the evenweave fabric with standard embroidery cotton. This held them in place for stitching with conductive thread. The connections have to go into the left side of each Sparkle and out of the right side to the next Sparkle in the chain.

To avoid crossed wires (threads), the Sparkles were arranged with their connection pads forming a rough “spiral”.

IMG_7857The conductive thread needs to form a good contact with the gold pads so two or three tight stitches were sewn at each connection point. The evenweave fabric proved to be a good choice as it enabled the stitches to be sewn right on top of each other. A simple running stitch connects one Sparkle to the next in the chain.

IMG_7854It is important to keep checking that different pieces of conductive thread are kept separate. In the picture to the left, too much frayed thread has been left on the back of the fabric after tying off. Threads from two separate knots are touching, causing a short circuit.


Once all the Sparkle pads were connected with the conductive thread, the first Sparkle in the chain was attached to the Crumble with croc-leads. (For more information on connecting up the Crumble, battery box, and Sparkle see the previous blog post, or the Crumble “Getting Started” guide.)

Screen Shot 2014-12-21 at 18.40.49The Crumble program is shown, left. Originally, I thought that Sparkle “0” would be the star at the top of the tree, which is why it’s gold, but in the end the shape wasn’t quite right. It would have been simple to re-program the Crumble to change the gold to green/red, but, shining through the felt, it looked green so I never got round to it..

IMG_7860Two matching Christmas Tree shapes were cut from the green felt and the Sparkles were sandwiched between them. Extra pieces of felt were inserted at the top, just behind the input pads of Sparkle 0. This stopped the front and back sticking together so the croc-leads could be connected and disconnected.

IMG_7872The Christmas tree was then decorated with glitter glue and stickers.

The battery box and the Crumble were concealed among Christmas cards on the mantelpiece and the croc-leads were sellotaped so that the ends dangled down. The croc-leads were connected to the Sparkle within the Christmas tree, so it hangs from the mantelpiece.

Crafty Crumble Creations: A colour changing lamp


This is the first in a series of posts, incorporating the Crumble Controller into simple craft projects, “helped” by my just-turned 5-year-old. The electronics aspect was a bit beyond him: he doesn’t yet have the motor skills to clip the croc-clips or to drag-and-drop the software blocks with a trackpad. He enjoyed working on the design of the lamp, though, and the whole project was completed quickly enough to hold his interest.

We used:

  • 1 laptop with Crumble software installed
  • 1 Crumble controller
  • 1 Sparkle
  • 1 micro-USB cable
  • 1 battery box with croc-clip attachments; 3 AA batteries
  • 3 croc-leads (red, black & green)
  • 1 plastic shower gel bottle (washed & thoroughly dried)
  • 1 cardboard box
  • 1 sheet of black card; silver wrapping paper & stickers
  • Scissors, hole-punch & sellotape
IMG_7601Sparkle to Crumble
The Crumble can be powered from the computer, via the USB cable, but the Sparkles need extra power. The red lead from the battery box was connected to the top-left pad of the Crumble (+) and the black lead to the pad below (-). Power passes through the Crumble to the pads on the top-right. The red and black croc-leads connect from the Crumble’s power-out + and – pads, respectively, to the top 2 pads on the left side of the Sparkle. The green croc-lead connects pad ‘D’ on the Crumble to the bottom-left pad on the Sparkle to send the data to the Sparkle. This is shown in the diagram, left.

The Crumble was connected to the computer, via the USB lead, and we began to experiment with setting the Sparkle colour.


The five-year-old was keen on red and green, but I managed to persuade him to go with a more muted colour palette of blue, violet and cyan. The next version of the Crumble software will include a “fade to..” command for Sparkle control which will allow a bigger range of colours to be used with smooth transitions.

The final program is shown to the right.

Screen Shot 2014-11-23 at 20.18.16
Once we had programmed the Crumble and were happy with the colours, we disconnected it from the USB lead and began to construct our lamp.

We found a box big enough to contain the battery box, crumble and sparkle and cut a whole in the top to stand the plastic bottle in. The sparkle was sellotaped inside the box so that it shines straight up into the bottle and the rest of the electronics were squashed in around it.

Meanwhile, the 5-year-old had found a hole punch and started making holes in a sheet of red paper. He turned this into a cylinder to cover the plastic bottle.

Aesthetically, I felt we could do a bit better. I wrapped the box in an off-cut of wrapping paper and replaced the red paper with black card. The 5-year-old had already worked out that it’s necessary to fold paper or card to make holes in the middle, so the cylinder became a cuboid. A few scattered silver dot stickers enhanced the random effect.


FINAL THOUGHTS: The lamp ended up looking better than I expected, given how quickly it was thrown together. The tangle of wires in the box, though, is not ideal: shorter croc-leads and a more secure way of fixing the Sparkle in place are required. A switch on the outside would also be useful so we could turn the lamp off and on without taking it apart.

Can you do any better? We’d love to hear about your Crumble projects!