I bought the Pimoroni Mood Lamp kit way back in March at the Raspberry Pi Birthday Party, but I held off building it until Louise could come around, especially as I was nervous about soldering all of those pins onto the Pi Zero so I thought it would be a nice project for us to do together. You may remember that last year Louise and I built the CamJam 3 robot kit together; she is a talented artist and pub landlady with absolutely no background in computer science and no knowledge about how any of this stuff works, so she’s a great person to try things out with.

So for those of you who aren’t familiar with the Pi Zero, it’s an even more tiny and cheap Raspberry Pi and it doesn’t come with GPIO pins already in place so you have to solder them on if you want to use them. Scary stuff for a novice solderer like me! In February, in time for the 5th birthday, Raspberry Pi announced the Pi Zero W which adds Bluetooth and WiFi to an already tiny and affordable device. The Mood Lamp was one of three kits that were released by Pimoroni at the launch of the Zero W. You can also get your hand on Pirate Radio, Scroll Bot and, as of a couple of weeks ago, the OctoCam – find them here.

So… on to the soldering. We started off watching the new soldering video which the Raspberry Pi Foundation brought out recently starring the lovely Laura Sach. I found Laura’s video to be really useful and interesting, but we also listened to the advice of soldering guru Stuart. As he pointed out to us, he’s been setting fire to carpets since he was 9 years old and so is experienced at soldering.

I had prepared for disaster and got a spare Pi Zero W and a hammer header in case the soldering went horribly wrong – thank you to both ModMyPi and Pimoroni for donating the spares (not that the former had much choice, they foolishly didn’t believe me when I said that the circumference of a pint glass was longer than it’s height and agreed to give me a Pi Zero W if I proved them wrong)… but I digress. The hammer header allows you to add pins to the Pi Zero W by tapping them in place using a hammer, so an excellent option as a back-up plan.

Stuart decided to solder five pins to start us off and hold it in place and then left us to it. He explained that it was important to make sure that we were heating the pin and the Zero and applying the solder to that and not the soldering iron. We had a go at a few pins, but Stuart wasn’t happy and told me to make sure I wasn’t just dabbing solder on the iron and letting in roll down. By the time the pair of us finished, we were pretty happy, but Stuart took a careful look and said that some of our joins didn’t have enough solder and so weren’t properly connected… and to think I was worried that I’d put too much solder on some of them. All told, we were there for around fifteen minutes, but it felt like much longer.

We were pretty pleased with ourselves when we’d finished so we sat down and got the kit out to try and figure out all of the parts… We had a bit of fun peeling off the plastic from the acrylic and laid all the bits out, but then we realised that we had still more soldering to do – the Unicorn Phat needed soldering too!!

Back to the kitchen we went, Louise decided to leave me to it and apparently I hit my soldering mojo and got the entire header soldered in a few minutes!

So, all soldered up, we were ready to go – I was quite interested to see the difference between the soldering on the zero compared to on the Unicorn Phat – I’d clearly improved by the second time!

Louise was confused by the how the pieces went together, but we quickly found the tutorial and before we knew it, it was all built and looking pretty, including our soldered Pi Zero W and Unicorn Phat header.

Thank goodness for Stuart’s ridiculous amount of tools, as we were able to clip off the excess bolt length on the Pi Zero W mount.

So, now we’d built our Mood Lamp, it was time to run the code – I put a Raspbian SD card into my pi-top, transferred the Unicorn pHat to test it. We followed the instructions on the Pimoroni GitHub for the Unicorn pHat to download and install the relevant library and examples. I figured random_sparkles.py was probably a good place to start, but when I ran it through Python 3, nothing happened. Stuart to the rescue… he opened Terminal and used the command

cd /home/pi/Pimoroni/unicornhat/examples

To access the directory and then used

sudo  ./random_sparkles.py

to get the code running – this frustrated me a little bit as I wouldn’t really have known to do that without his help. I know to run code through Idle, but I wouldn’t think to use Terminal and sudo without him telling me to – especially ./ which I’ve never seen before.

Next step was to get the code to run on start up – again I had a few problems with that, I followed this great guide from Les Pounder, but managed to accidentally leave the last line of the code as a comment with a # at the beginning – a little frustrating, but entirely my fault. We also discovered that again we need to use ‘sudo’ to get the code to run on start up, this time within the crontab settings (whatever that might mean).

So, we got the random sparkles up and running on start up and decided to transfer the SD card and Unicorn pHat into the Pi Zero W and get the mood lamp up and running. Unfortunately, we had no luck and I began to worry that I’d soldered everything wrong. Stuart sat and used VNC to check the pi was working and as far as we could see, everything was running as it should, but no random sparkles. Stuart decided to pull the Pi Zero out completely to check nothing had come loose and this point he threw his hands in disgust and gave it to me… it seems when I’d put the pHat back on the Pi, I’d not mounted it in the right place, it was just on the front row of pins and not on all 40 pins! What a wally!

I have to admit to finding this a little more stressful than I’d hoped, especially with the whole ‘sudo’ thing, and I have absolutely no idea where to start with connecting it to Twitter, but I’m glad I’ve got it built and it does look kind of cool. I think I’d like to use one of the other samples as the random_sparkles was a bit too quick for my liking, but that means going back into Crontab and putting all the bits back into the pi-top and I’m not sure I have the energy for that right now!

So, it’s an easy to put together kit, I just don’t feel like I’m quite confident enough with running code on start up or what to do when things don’t work first time!

At least Louise and I can both say that we know how to solder now, anyway!

[edit] As of June 2017, there is a version of Scratch 2.0 on Raspbian which makes this worksheet obsolete [/edit]

I’ve been running a few workshops for Crossover Solutions and have created some Raspberry Pi Physical Computing resources that seem to go down well with both children and adults and so, as a little Easter gift to you all, I’ve decided to share the worksheets.

There are four in total – ‘Your First Circuit’ ‘Scratch’ ‘Python’  and ‘Next Steps’, all designed to be an introduction to physical computing. My experience has been that pupils will get three LEDs blinking in Python within an hour – I’m sure you could do it quicker, but it’s really important to discuss with the pupils what they’re doing at each stage and why so I tend to take my time to ensure that conversation happens, particularly since this can be used as a transition from Scratch to Python as well as an introduction to electronics.

As always, huge thanks to the Raspberry Pi Foundation for the inspiration to produce resources like this, as well as their never ending support.

Get in touch if you’d prefer an editable version and I will send it over to you, otherwise click on the link below for a pdf.

link: Workshop – crossover

Crossover Workshop by Cat Lamin is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.

It’s taken me far too long, but I’ve finally got my hands on a Micro:bit! I often get asked about these little micro-controllers and whether they are useful to have in the classroom so I’m looking forward to testing them out. Thank you very much to Nic Hughes for the loan!

The first thing to say about the Micro:bit is that unlike a Raspberry Pi, it’s not a computer; it’s a micro-controller like an Arduino, which needs to be plugged into a computer to have code uploaded to it. In contrast, a Raspberry Pi is a computer which does not need to be connected to anything else to work. This means that the Micro:bit is slightly more limited than a Pi, but it’s still a cool device.

So, let’s take a look at the physical hardware. The Micro:bit has a number of exciting features, not least of which are a host of components, which are clearly labelled on the back of the device – in particular, a compass, accelerometer and BLE antenna. I really like how clearly everything is labelled on the back for the device, this can be a great teaching point – what do we think each of those things do? How can we integrate them into our code?

The front of the device has 25 red LEDs in a 5×5 array. There are also two programmable buttons, 3 hardware pins, a 3V pin and a ground pin which can be used for add ons like NeoPixels or a growing range of Micro:bit boards designed to fit onto the Micro:bit like HATs on a Raspberry Pi.

In order to use the Micro:bit, you’ll need to head to the Micro:bit website. I suspect that there is an offline version of the various code editors, but for now I’ll work on the assumption that I need to work online. I know you can download Mu (pronounced moo because the creators liked the idea of ‘teachers saying moo in class’), which is a micro-python code editor for the Micro:bit, but I’m not sure about the other code editors.

Given my primary background, I will focus on block-based coding for now, but I can always follow up with a look at micro-python in a few days.

I love that there seems to be a wealth of activities on the website, including a special ‘Mother’s Day Challenge’ (For Americans and other non-UK people, Mother’s day in the UK falls in the middle of lent, which is usually in March, rather than mid-May).

For now, I’m going to be looking at the ‘Let’s Code’ section of the website.

When I first looked at the site a few weeks ago, the JavaScript Blocks editor was still in Beta, but Nic was very firm that we should be using it over the previous blocks editor made by Microsoft. I’ve also seen a tweet today showing that python-blocks is in development, although still only in Alpha at the moment. I can’t wait to see what it looks like!

It’s worth taking a look at the projects page for some ideas about where to start with the Micro:bit and there are a few teachers coming up with schemes of work that use it (I suggest getting in touch with Spencer Organ who has written an entire scheme of work around Harry Potter).

Since I’ve had so much fun making animated pets on the Pi lately, I figured an obvious start point for me would be to do something similar on the Micro:bit. Interestingly, when I went into the code window, it had remembered the piece of work I did several weeks ago when Nic first showed me the Micro:bit, which saved me having to hunt around and figure out the code!

So here’s how the screen looks – it has a nice familiar feel to it since it’s based on Blockly and is therefore very much like Scratch. The blocks are nicely colour coded depending on what you want them to do. I’m particularly curious about the ‘radio’ and ‘music’ options – I think you can allow Micro:bits to talk to each other, but I could be wrong – definitely something I’d like to investigate further.

Here’s a closer look at the code I’ve written – the ‘pet’ was a little harder to draw on 25 pixels so it looks a bit weird.

One frustrating thing about the Micro:bit is that you need to download the code and then manually drag and drop it into the Micro:bit although I’m told on a PC you can set the download location directly to the Micro:bit, still it’s a bit of a faff.

A really cool feature of the Micro:bit website is that you can test your code on the website – in the video below you can see that you can test the ‘shake’ feature both by clicking on the shake button or by manually ‘wiggling’ the device. I think it’s really important that we remind children to check their code regularly as it can be really hard to find an error in your code if you’ve written loads and not checked it.

In the second video, you can see the code running on the actual Micro:bit.

There seem to be lots of input options to use instead of ‘on shake’ and I’d be interested in giving them a go, although I’m not sure what they mean. There are also other options to drag in. Take a look below:

Another nice little feature of the blocks editor is that you can view your code in JavaScript. I look forward to this being possible for Python too, which looks like it’s in development based on Nicholas’ tweet mentioned above.

There are a few ‘advanced’ options I’d be keen to explore, as well as the ability to add in packages for add ons which seems intriguing. Hopefully I’ll have a chance to explore some more features soon.

So, what do I actually think about the Micro:bit?

I’m actually more impressed than I thought I would be, I was expecting to be underwhelmed and instead I had great fun playing with the Micro:bit. The website is fairly easy to use and has some lovely features. I look forward to seeing it develop further. I know there are teachers crying out for schemes of work relating to Micro:bit so perhaps that’s something that needs developing further and in my brief hunt around the site I didn’t see any obvious explanation of some of those features in the code editor, but I admit I wasn’t looking too hard.

If I had my way, I’d like to see teachers using Micro:bit with a Raspberry Pi to really emphasise the technology and make clear how unique and exciting digital making can be – check out this resource on using the Micro:bit with Pi. However, if you forced me to choose between Micro:bit and Pi, Pi would win every time, it’s just more versatile and has more opportunity to develop your skills.

Micro:bit is a great place to start on a journey towards digital making and at £12.50 (or £15 if you want a battery pack with it), it’s fairly affordable, but it is simply a start point and you can achieve so much more with Arduino and Pi – for schools it is a good way to introduce text-based languages and I am particularly looking forward to the new block-Python that is being developed. In the long term, however, I know what I’d rather see being used.