scratch – dave's blog of art and programming

Tanglebots workshop preparation

It’s workshop time again at Foam Kernow. We’re running a Sonic Kayak development open hacklab with Kaffe Matthews (more on this soon) and a series of tanglebots workshops which will be the finale to the weavingcodes project.

Instead of using my cobbled together homemade interface board, we’re using the pimoroni explorer hat (pro). This comes with some nice features, especially a built in breadboard but also 8 touch buttons, 4 LEDs and two motor drivers. The only downside is that it uses the same power source as the Pi for the motors, so you need to be a little careful as it can reset the Pi if the power draw is too great.

We have a good stock of recycled e-waste robotic toys we’re going to be using to build with (along with some secondhand lego mindstorms):

Also lots of recycled building material from the amazing Cornwall Scrap Store.

In order to keep the workshop balanced between programming and building, and fun for all age groups, we want to use Scratch – rather than getting bogged down with python or similar. In a big improvement to previous versions of the Pi OS, the recent raspbian version (jessie) supports lots of extension hardware including the explorer hat. Things like firing the built in LEDs work ‘out of the box’ like this:

While the two motor controllers (with speed control!) work like this:

The touch buttons were a bit harder to get working as they are not supported by default, so I had to write a scratch driver to do this which you can find here. Once the driver script is running (which launches automatically from the desktop icon), it communicates to scratch over the network and registers the 8 touch buttons as sensors. This means they can be accessed in scratch like so:

Training teachers in coding, and thinking about e-waste/recycled robots

We recently had the second inset training day in programming related activities at Truro school. Following on from the previous session I didn’t want to introduce too much new stuff, so we concentrated on going back over Sonic Pi and Minecraft/Python programming in the morning, then discussed a lot more about our future workshops in the afternoon. These will include children from most of the primary schools in the Truro area and take place during the next term. I also wanted to use the day to work on some specific ideas the teachers wanted to get going. One of these involved running a Kinect camera with the Pi, which we managed to get more or less working – reading depth data in Python for potentially plugging into Minecraft at a later date.

The big idea I wanted to get feedback about was the use of robotics and electronics in conjunction with code (the photo above is my desk while preparing the day before). I didn’t have any lesson plans for this, but based on some comments from the first workshop and from playing a bit with this during CodeClub teaching I felt it might be good with this age group, who already know quite a bit about screen based activities. To keep costs down (as well as building in issues like e-waste) we’re planning to make use of recycled junk to extract motors from toys and hack them to do different things. It seems this doesn’t cause too many issues from safety POV (everything will be low-voltage and we can check everything beforehand), even the use of soldering irons seems to be acceptable as they have supervision.

The advantage of using code to move real things (as shown by a long history) is that it directly connects programming with the world outside of the screen (where it most certainly now has great importance in our lives), and at the same time results in teamwork – as it’s not easy for a single person to make a robot while programming it. When we tried this at Troon Primary they self organised into a group with one person programming while another was building stuff in lego and a third provided excited communication between them and more or less managed the task. Other programming activities tend to be more individualistic – with the possible exception of networked Minecraft, which is important but a very different form of collaboration.

Why teach Kids Coding? (Royal Cornwall Show update)

Setup and coffee time at the Pi Cube before the crowds arrive

On Saturday I teamed up with Falmouth University’s Makernow team to do a kids coding event at the Royal Cornwall Show with a new Raspberry Pi cube (based on the one used at the DeerShed Festival last year). We had a constant stream of families and kids wanting to try Scratch coding, and we had a 50/50 gender balance in terms of helpers which I think with these sorts of events is critical.

The part I like best about public events like this are talking with the parents and teachers. The best questions are the fundamental ones: “why should we be teaching them how to program?” which was a great opportunity to get my thoughts straight – the official economic reason is not one I’m so motivated by: “to encourage more talent in the tech sector”. The actual reason I do all this (mostly on a voluntary basis) is the feeling that as we find ourselves living in a computational society, where everything we do is algorithmically processed, the future for people who only know how to consume technology is very different from those who are not afraid to question it, who know it’s possible to take it to bits and rebuild it in new ways.

This is also the reason that I can’t get very excited when teachers tell me they are buying iPads for use in their school – there are some interesting programming environments on them, but the kind of creativity they support cannot, due to Apple’s core business model, encompass this kind of questioning – they can’t escape the sandbox. For example, when I last checked, you can program iPads, but not share the code or work collaboratively as it would bypass the AppStore distribution model to do this.

This relates to the answer I gave to “why should we get a Raspberry Pi” – as it provides a platform that encourages a fearless relationship with technology, it doesn’t have the family email account on it, it’s cheap and nobody cares if you manage to delete the entire operating system, just copy a new sdcard. This stuff has to be possible, and encouraged – if we are to eventually have a society that can have any meaningful debate on increasingly thorny computational/network/society issues such as those related to GCHQ mass spying.

Back to the kids – it was interesting that the majority of the older ones had already used Scratch, either as part of their normal school lessons, or an after school activity (anecdotally, this is sharp improvement over the last year or so). Some of them were keen to show off their skills, which was a great way to demonstrate to the younger ones what was possible.

For the older ones I’m continuing work on the Minecraft API coding project – making simple 3D primitives to demonstrate functional programming in Python. You can explore the results of your programs by walking around and digging into structures generated in a familiar world. More on new versions of that soon.

Scratch -> Lego Mindstorms

A bit of hardware hacking for Troon Primary CodeClub, who have tons of old style Lego Mindstorms they don’t use any more, and after a year of Scratch programming on their PCs are just getting started with Raspberry Pi. We’re using this Scratch modification together with the hardware I’m making which is based on this circuit. The main thing here is an L293D Motor Controller IC which can drive 2 DC motors in both directions. You can write the hardware code in Scratch like this to control the lego motors:

The most tricky part in this whole endeavour has been physically connecting to Mindstorms. At the moment I’m having to use crocodile clips which won’t work long in normal classroom conditions – but I’m wary of destroying/modifying the connectors as they’re not made any more…

Slub at the Deershed festival

Deershed is a music festival designed to accommodate families with lots of activities for children. Part of this year’s festival was a Machines Tent, including Lego robot building, Mechano constructions, 3D printing and computer games.

Slub’s daily routine in the Machines Tent started by setting up the Al Jazari gamepad livecoding installation, a couple of hours with Martyn Eggleton teaching Scratch programming on an amazing quad Raspberry Pi machine (screens/processors and keyboards all built into a welded cube).

At some point we would switch to Minecraft, trying some experiments livecoding the LAN game world using Martyn’s system to access the Minecraft API using Waterbear, a visual programming language using a similar blocks approach as Scratch and Scheme Bricks.

During the afternoons Alex and I could try some music livecoding experiments. This was a great environment for playful audience participatory performances, with families continually passing through the tent I could use a dancemat to trigger synths in fluxus while Alex livecoded music designed to encourage people to jump up and down.

One of the most interesting things for me was to be able to see how lots of children (who mostly didn’t know each other) collaborate and self organise themselves in a LAN game, there was quite a pattern to it with all the groups:

Mess around with Minecraft as usual (make some blocks, start building a house).
Find something built by someone else, destroy a few bricks.
Snap out of the game to notice that the other kids are complaining.
Realise that there are other people in the world – and they are sat around them!
Attempt to fix the damage.

At this point other people would join in to help fix things, after which there would be some kind of understanding reached between them to respect each other’s creations. This has all really inspired me to work on Al Jazari 2 which combines a lot of these ideas.

Deershed Festival, Sonic Bike Lab, Fascinate Festival

Preparations for a busy summer, new Al Jazari installation gamepads on the production line:

This weekend Alex and I are off to the Deershed Festival in Yorkshire to bring slub technology to the younger generation. We’ll be livecoding algorave, teaching scratch programming on Raspberry Pis and running an Al Jazari installation in between. Then onwards to London for a Sonic Bike Lab with Kaffe Matthews where we’re going to investigate the future of sonic bike technology and theory – including possibly, bike sensor driven synthesis and on the road post-apocalyptic mesh networking.

At the end of August I’m participating in my local media arts festival – Fascinate in Falmouth, where I’ll be dispensing a dose of algorave and probably even more musical robot techno.