When the Raspberry Pi was 1st launched – controlling the GPIO ports other than through terminal commands and/or Python was virtually impossible – or at least very difficult. Very quickly a few developers realised that it was possible to ‘connect Scratch’ to the GPIO ports – hence came Pridopia’s Pi_Scratch and Cymplecy’s ScratchGPIO. Pi_Scratch requires active MESH to be enabled whether as ScratchGPIO will run without modifications once installed. Simon Walters – also known as ‘Cymplecy‘ has been working tirelessly on his brainchild that is ScratchGPIO and it’s come a long way – now on version 8. I have a preference towards ScratchGPIO myself due to the extensive support for addon boards such as PiGlow, BerryClip , RTK motor controller & HAT’s (to many to mention) making it a very powerful interface. The main aim with Scratch is to gently introduce school children to programming and robotics – ScratchGPIO does exactly that. I also prefer the physical GPIO numbering to BCM when working in schools, particularly with KS2 and KS3 pupils.
So the ‘Hello World’ equivalent in ScratchGPIO is simply blinking an LED continuously (in a loop) with 1 sec intervals; we have here used pin 11 for the output. For the full tutorial go to Simon’s ScratchGPIO page here.
With the release of Raspbian Jessie in 2015 the (Scratch) GPIO server is allready installed – full documentation here. There are some differences in GPIO Server and Simon’s ScratchGPIO , this is explained in this post.