The PiStop

I’ve realised that I haven’t yet written a blog post about my favourite bit of kit for the Raspberry Pi, the PiStop by 4Tronix.

So first lets talk about why I like it so much then I’ll talk through a demo of using it. Earlier in this blog, I talked about the CamJam EduKit and how much I liked it, the biggest problem was the wires – for younger and not so dexterous fingers, all that work with fiddly LEDs and resistors and cables is quite a hassle; not to mention just grasping the whole concept of why. When you finally get everything wired up, the next task is to write some code in either Scratch or Python and THEN you get an exciting output of flashing lights. Not so with the PiStop – it neatly slots over 4 of the GPIO pins (three programmable GPIO pins for the LEDs and one ground to complete the circuit) and then you can just load up Scratch and code away. For me, this is ideal for the younger and more easily distracted children as it’s quick and easy to make something actually happen with a few blocks of Scratch code. It’s also easily extendable – once you have one flashing light, can you make the other 2 flash? Can you make a traffic light sequence? Can you now write the same code in Python? Then once all of those activities are complete you can then run the whole activity with cables, breadboards and LEDs, but now the children are excited, they already have an idea of how to get the code working and building the circuit is like moving on to the ‘grown up’ stuff like the CamJam kit.

So, how do you plug in your PiStop? I’m a creature of habit so I tend to always plug the PiStop into the same place – it can actually be placed anywhere on the pins where you have one ground and 3 GPIOs together.

I’ve mentioned before that there are two different numbering systems for the GPIO pins, the picture below shows both number systems for the model A and B Raspberry Pis, which are the older versions with only 26 pins; both the B+, A+ and 2 models have 40 pins, but the first 26 are the same as below. Raspberry-Pi-GPIO-Layout On this diagram, the ground pins are labelled in white, the programmable pins are green and the live, powered pins are red and orange. The most popular labelling system, known as BCM, is listed in the white boxes on the outside, whilst the simpler numerical system is written on the pins. From my experience ScratchGPIO uses the simple numerical system, but it might work for both! My usual spot for mounting the PiStop is from numbers 9-15.

The first thing you’ll need to do is to make sure that Scratch GPIO is installed on your Raspberry Pi – details for how to do this from Scratch GPIO creator Simon Walters can be found here.

Once installed on your Pi, load it up and cross your fingers – you should get a message box pop up telling you that remote sensor connections are enabled – if you don’t you will need to run some updates because it means it’s not working properly (boo hiss). I came across this a few times with the latest version of Rasbian and I’m not going to lie, I had to resort to getting someone more technical than myself involved.

Screen Shot 2015-03-30 at 13.43.01So, let’s assume that you have got Scratch GPIO working fine and your PiStop is plugged in as in the photos below:

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So to make the first light turn on we need to use the control tools on Scratch – our key command is ‘broadcast’ with high being on and low being off.  See the photos below for step by step instructions for turning the first light on and off ten times.Screen Shot 2015-03-30 at 16.21.24Screen Shot 2015-03-30 at 16.21.31Screen Shot 2015-03-30 at 16.21.39

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You’ll notice that I’ve put ‘wait’ blocks in between each of the broadcasts, inevitably the children will miss these out once in a while, which will cause the lights not to work- this is great because you can reiterate both the importance of debugging and that code does exactly what you ask so your instructions need to be clear. IMG_4908

Once I’ve shown the children this step, I usually ask them to figure out how to get the other two lights on (pin 13 and pin 15) then the challenge is to try and make a traffic light sequence. I was fairly impressed when a couple of boys extended themselves by using the CamJam Python code with the PiStop to broadcast what they referred to as a disco, whilst on the screen a selection of messages appeared in their Python window using the print command.

So, basically, this is a very simple, cheap piece of kit which is really easy to use and a great stepping stone to more complex code. I would definitely recommend that any Raspberry Pi teachers get at least one PiStop into their classroom as a starting point for physical computing.

Good luck everyone and enjoy coding!

PS For anyone who’d prefer a real life demo, my next coding evening will be on Tuesday 5th May in Twickenham

Coding Evening Part 2

Just a quick post…

I’ve met with so many lovely people in the last few weeks and I’ve mentioned my coding evening to them so I thought it was worth writing a quick post to make the event page easy to find. I also want the opportunity to explain a little about how I want the evening to run.

So, way back at the end of January, I hosted my first coding evening, with the goal of getting teachers, Code Club volunteers and Raspberry Pi enthusiasts into one room just to see how everyone is getting on.

It turned out to be a lovely evening with lots of great chat about ideas for teaching the new computing curriculum and lots of enthusiasm to repeat the event.

For next Friday I’ve once again booked the lovely function room of the Stokes and Moncreiff pub in Twickenham. I hope to have three Raspberry Pis set up for people to try out or demonstrate on. I also plan to bring loads of resources and print outs from Code Club, Code Kingdoms etc. There’s an added bonus of the pub downstairs serving beer, wine, spirits (and soft drinks) as well as pleasant food which they will deliver to the function room. There will be Code Club volunteers, technicians, Raspberry Pi fans and an iPad specialist on hand to answer your questions. It would be lovely if people are willing to stand up and talk for two minutes on a subject of their chosing, but I’m certainly not going to enforce this.

So, if you’re still interested in coming, click the link below, sign up (it’s free) and we’ll see you there for a burger, beer and a great conversation about the computing curriculum:

Picademy – Why Apply?

As you may have noticed, I’m a bit of a Raspberry Pi fangirl, which came from attending Picademy last July. I did what many primary schools did – heard about Raspberry Pi and bought some Maplin kits which then sat on the shelf because I didn’t really know what I was doing. I had a look on the internet, but I just wasn’t really confident enough to give them a go – I did manage to set them up once or twice and desperately tried to use LXTerminal to make a jelly baby scream, but I really didn’t know what I was doing. One day, while checking twitter I happened to see a post about Picademy and started doing some research – at that point they had hosted one Picademy and were advertising for two more in June and July – luckily for me the July course coincided with the end of term and so I made a video and sent off my application; once my place was confirmed, my school agreed to pay for my expenses and I was all set for two days in Cambridge.

The first thing I really loved about Picademy were the emails that started flying back and forth beforehand. Within an hour of being offered a place, Christine, a teacher in Bradford, had agreed with me via twitter to try to get everyone staying in the same hotel. Within a few days about 80% of us were booked into the same Travelodge on the outskirts of Cambridge and we were getting excited about meeting each other.

I was the second person to arrive and I headed down to meet Tom Sale in the hotel bar for a quick meal. As we sat there more and more people arrived, some people recognising each other, others of us being strangers to everyone – people were offering to collect other members of our group at the train station, we were starting twitter hashtags around our jokes and, much to Carrie Anne‘s dismay, the beers were flowing freely. It was a fantastic bonding experience and as the evening drew to a close, we booked our taxis to PiTowers for the morning.

The first day of Picademy we arrived and had to chose one of 4 tables – the tables were labelled with the names of 4 ‘master teachers’ from our group – much to our surprise, several of our new friends were already making a mark in the world of computing. I chose to sit with Matthew Parry, a robotics specialist working in a special school and our adventure began.

Most excitingly, we were starting Picademy on the day that Raspberry Pi B+ was launched and so everyone one of us had a brand new B+ in our goodie bags – we were the first people in the world to start using one – a huge honour!

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After a brief intro from Carrie Anne Philbin, we were taken into another room to look at some Scratch GPIO and Minecraft coding in Python – both of which were new and interesting to me. After a lovely lunch we were then shown how to set up a PiCamera and then spent some time with Sonic Pi – Unfortunately for us, we were the only cohort to not have the experience of Sam Aaron showing us how to live code music, but I have since seen him perform and can honestly say that he is amazing!

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The lovely people at The Raspberry Pi Foundation took us out for a meal in Cambridge and then we headed to a nearby pub to start discussing our independent project ideas for the next day – there were some really cool ideas flying around like coding a Minecraft version of Portal or using plates and tin foil to make a dance mat and everyone was really excited for the next day to come around. Back in the hotel bar, more ideas were bouncing around the table, some ludicrous and some perfectly feasible.

When we sat down the next day, Matthew revealed to us his idea – while the other tables in the room split off into pairs or small groups, we stuck together and planned our Tweeting Babbage Bear.


The idea was to use the Raspberry Pi mascot Babbage Bear and make a twitter bot which photographed you and sent it to twitter; the only difficulty was getting permission to pull apart the beloved bear!

We split into teams with different task – Matthew and Hannah worked on the code for photographing, whilst Eve and I set about finding out how to tweet from the push of a button attached to the Pi with various other members of our team working on other ways to make Babbage interesting, from sounds to LED vests. All credit to Ben Nuttall of the Foundation who very patiently guided us through the set up, using GitHub and finding the right commands for Twitter API and apologies to everyone else for the massive scream of delight from Eve and myself when we finally got the code to work. We were so proud of our tweeting Babbage and particularly so when a few months later Ben turned the project into a resources on the Raspberry Pi Website.

After receiving our badges our adventure at PiTowers came to an end; however, that wasn’t the end of the story at all.

Since Picademy, not only have I kept in touch with my cohort, I’ve come in contact with members of the other cohorts via Google, Twitter and through meeting them in person at events. I’ve also made contacts with people wanting to join Picademy who want to ask my advice or just to find out about what it’s like. I’ve become part of the Pi community, making dozens of new friends, some of whom I’m finally met this weekend at the Pi Birthday party. I know that if I have a teaching or Pi problem, dozens of helpful people are simply a tweet away. Through my contacts I’ve ended up speaking at BETT and organising coding evenings and, most importantly, I’ve gained the confidence to affectively teach the children in my care as well as to share my ideas with my fellow teachers.

Picademy was one of the best experiences of my life and I would thoroughly recommend it to anyone else.

PS Here are some pics of the destruction of Babbage – not for the faint hearted!

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PPS – this photo was captioned ‘Certifiable’ and was taken just after we became RCEs – I’m meeting these two lovely ladies for some cocktails in a few weeks so not only have I made amazing professional contacts, but I’ve also made a great bunch of friends!


Astro Pi Competition

Yesterday I was lucky enough to attend the Raspberry Pi third birthday party event in Cambridge. While I was there I took the opportunity to talk to the lovely Dave Honess about the competition he is helping to run for Raspberry Pi in collaboration with the UK Space Agency, Astro Pi.

The competition was launched a month ago at BETT, and I will readily admit that I wasn’t particularly fussed about getting involved. I wasn’t inspired and didn’t think I had the time to take part; however, after a long chat with Dave, I now feel really enthusiastic and excited about it as well as being full of ideas.

So what is the idea? One of the astronauts heading to the International Space Station, Tim Peake, has agreed to take a special Raspberry Pi into space with him. They’d like schools and Code Clubs to think up ideas for using the Pi and it’s sensors in space so that they can send their code into space!

Dave pitched the idea to me by suggesting that the Pi would be like a device at home on the shelf. What would you like it to do? What do you think an astronaut might like to have it do? Perhaps it could tell a joke whenever the motion sensor detected the astronaut go past or else display the flag of the country the station is above. The KS3 and 4 competition seems more geared towards recording data and results, but for primary, there seems to be a push towards a more fun app being planned and designed. Also, in a primary school the children just need to come up with an idea and then the guys at Raspberry Pi will create the code.

So, here is the Astro Pi board:


There are a number of sensors on the board as well as a basic LED matrix to display simple designs on. Here is the listed hardware:

  • Gyroscope
  • Accelerometer
  • Magnetometer
  • Temperature sensor
  • Barometric pressure sensor
  • Humidity sensor
  • 8×8 RGB LED matrix display
  • Visible light or Infra-red (Pi NoIR) Cameras
  • 5 button joystick
  • Additional functional push buttons
  • Real time clock with backup battery

I’d like to find a video showing what conditions are like in the Space Station with zero gravity etc. and use this as a discussion point for what you might need if you were there. From this you could move on to what you would miss most if you were space for a bit of cross curricular PSHCE. Finally, this would lead on to what could you use the Raspberry Pi for in space- what do you think the astronauts might want or need that the Pi can provide?

<edit> A video of a ‘fly through’ of the space station can be found here which features an astronaut floating from one end of the station to the other and could be used as a starting point for discussion.</edit>

The children could then work in small groups and develop their ideas for a useful app in the space station – I’d also spend a little bit of time looking at the experiments theme ideas on the Astro Pi website (Spacecraft Sensors, Satelite Imaging and Remote Sensors, Space Measurements, Data Fusion, Space Radiation), but I think from a primary perspective it would be simpler to focus on ways to entertain the astronauts while they’re away from home.

I’m quite excited to get involved – entry seems very easy and I think it could be done in a single afternoon rather than spending too long fitting it in. I think you could get children really excited about science and space and bring in some PSHCE too so it’s got some good cross curricular links. What more could you want? With a few more resources in place it should be an excellent and fun competition for everyone to be involved in.

So, very simply, I’d like to encourage more of you to take part in this competition – the more people who get involved, the more likely this competition will run again and I think it would be a great idea to get children interested in coding – a real time application for code and the Raspberry P. The competition closes on 3rd April, so you still have a month to get your ideas together.

<edit>Raspberry Pi have now created a worksheet for the Astro Pi competition which can be found here </edit>

<edit 2>We received results from the first stage of the competition last week-I’m so proud to be able to say that one of our teams was highly commended by the judges! Well done boys <edit 2>