The crumble is an electronic board which you can attach up to two motors, lights, buzzers etc and attach lots of switches and sensors to control how they operate. It plugs into your pc via usb and you can program it via the free drag and drop crumble software. Motors and buzzers are powered by 4.5v-5v battery packs.It is made by Redfern Electronics & you can get some great accessories from Redfern and 4Tronix.
Crumble Maker Cards These cards are the first of many helping pupils to work out how to wire and program this device themselves. The cards can be used independently by most pupils. I have used basic components for these first cards but I will be extending the range to include the excellent Crumbs produced by 4tronix, for a few pounds more these are much more rugged and will survive longer in the primary classroom. Ultimately I would love schools to make up packs and allow pupils to take these home and kickstart the junior maker movement. I would recommend that pupils use Scratch first at least to the Maths Quiz level as the programming blocks are modelled on Scratch and pupils are able to program very independently once they have the basics of sequence, selection and variable use established.
Scaffolding more complex code solutions where conditions are checked before code is run. These scaffold files enable pupils to think through one of two conditional selection checks before coding. They are ideal for steering buggies using buttons, adding a distance sensor or line followers.
Peter Gaynord CAS Master Teacher has made some excellent videos outlining how to use Crumbles with a fairground rides DT Project (Linked with permission)
My thanks to Simon Walters @PrimarySi who has helped me iron out a few bugs in my thinking. All errors are of course my own.