ScratchGPIO is designed as an easy way to use Scratch on the Raspberry Pi to control lights/motors/sensors and switches using the GPIO pins.
You can use it with £5 worth of bits from CPC to make some lights flash, you can plug in £10 add-on boards from some great maker-type companies such as Pimoroni, 4Tronix, ModMyPi, Cyntech and other boards direct from makers themselves such as Jason Barnett and Gordon Henderson.
And then you can use it to control robot vehicles from £20 to £100. I’ve even heard of someone using it to automate a firework display!!
To get started – follow this link to Installing