Raspberry Pi 2 hands-on

Raspberry Pi 2 setup in son's room
We’re now a FOUR Pi household. One Raspberry Pi is our wireless print server, enabling us to use an old cheap laser printer to print from Macs, Raspberry Pis, iPhones and iPads; another is our kitchen radio; the third is for my tinkering.

Enter our 4th Pi. It’s a brand new improved RaspberryPi model 2 I bought for Son A. It now boasts a quad core processor (I’m guessing that’s why you see 4 raspberries when it boots) and is generally regarded as being 6 times more powerful / faster / tastier. And yet it still costs just £30, less keyboard, mouse, case, screen, wifi dongle and SD card. Adding all of those things except the screen cost about £85 bundled from Pimoroni, though you could do it more cheaply, especially if you have a keyboard, mouse and power supply spare. The monitor is a supermarket TV that cost about £120, but again you could save money here.

We got a full starter kit with a lovely cool blue Flotilla Pibow Coupe case from the people on the good ship Pimoroni. And I’m very envious. It runs and boots darn quickly, and seems quite happy with a web browser and other applications open at the same time.

Audacity running on a Pi2

I’ve found that the audio editor Audacity seems to work pretty well (I did over-clock the Pi). There’s a small delay when playing audio over HDMI, but the audio does play in-sync. Next I’ll try analogue audio playback and also try my Griffin iMic USB audio adaptor for playback and capture. This could a great tool for school radio stations, or just teaching audio editing and making podcasts. I’ll be doing some more work on this, and looking at possible playout solutions. CoolPlay for Linux, anyone?

It will play YouTube videos back in the browser, at least at standard definition, the graphical desktop is much, much faster than previous Pis, to the point where you could use this as a general computer. Son A installed GIMP for photo editing and Open Office for word processing, and I just installed CUPS so he can print his homework on the colour inkjet plugged into our iMac or the old Brother laser printer plugged into the Pi print server. I didn’t even need to configure it, it just found the printers on our home network. Flickr is perfectly usable on the default Raspbian web browser (‘Web’) and I’m happily writing this blog post on the Pi2 too. A hell of a useful tiny computer for a school, or kid’s bedroom at only £30 (around £200 including a TV and all the bits) – and it’ll save squabbling over access to the family iMac.

Son A has a cheap Sainsbury’s 22 inch Celcus LED22167FHD TV in his room and we got the picture filling the screen nicely with these settings in /boot/config.txt:


# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
disable_overscan=0

# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
overscan_left=10
overscan_right=10
overscan_top=-17
overscan_bottom=-17

Now I want a Pi2 of my own. Can I justify becoming a FIVE Pi household?

The Raspberry Pi has certainly come a very, very long way in 3 years. Here’s what the desktop looked like back in 2012 when I got my first Pi (still going strong).

Posted in computers, Linux, Raspberry Pi, Raspbian | Tagged , , , | Leave a comment

Where’s the joy?

A couple of weeks ago I took part in a school INSET day, and I have to admit I didn’t recognise the name of the guest speaker, all I knew was that he was a world champion ping-pong player. I immediately had visions of the character in the radio version of Little Britain – Denver Mills – a silver-medallist Olympian who gives speeches at corporate events likening almost anything, selling double-glazing, making furniture, packing fruit, to running the 400 metres.

As soon as the speaker appeared, I realised my mistake – it was the Times journalist Matthew Syed, and I recognised him immediately from some thoughtful TV appearances.

It was a slightly surreal event, hundreds of us crammed into a new but shabby, windowless school sports hall. They hadn’t provided a PA for Matthew, who has a lovely voice but he’s very softly-spoken. So he stood in the middle of the aisle so more people could hear, and he was right next to me, which was good because I could hear him very well and make eye contact, but also not good because I had to pay bright-eyed attention for the best part of an hour.

I’m probably going to hideously over-simplify his message, and I admit I’ve not read his book, but here goes.

He made a convincing argument about the dangers of the way we in the Western world regard talent and about fixed versus ‘growth’ mindsets. He argued that talent is hugely over-rated. Saying (and thinking) that you are born with (or without) a talent for, say maths or sport is, he says, hugely damaging and limiting. It prevents people from reaching their full potential.

He had two powerful examples to back this up. He had been told that his reaction times were some of the fastest of anyone on the planet. Armed with this pleasing accolade about his talent, when he interviewed the tennis player Michael Stich he had a knock-about, and told him that he could return any ball Stich served at him. He never even saw the first ball coming, having only a vague sensation of something whooshing past his ear. Stich served 4 straight aces and Syed never got near the ball.

So much for the fastest reaction times in the world. Talking to sports scientists, and getting himself wired up to some sports tech, he discovered he was looking in the wrong place. He’d been looking at the ball. Professional tennis players don’t look at the ball, they read almost imperceptible signals from their opponents’ upper body positions that enable them to read where the ball will go even before it’s been struck. Even armed with this knowledge, Syed couldn’t return a tennis serve any better. Pro tennis players’ reaction times aren’t any faster than yours or mine – but what they have done is spend years and years practising reading these subtle signs. Not so much innate talent, more hard graft.

His other example was about his own sport of table tennis. A huge proportion of the top players in the UK all lived on the same street. His street. This was not because of some freak localised genetic mutation. This because on this street there was one of the few 24-hour table tennis facilities in the country, to which everyone on the street had a key, and an amazing coach. Talent played a small role – some people will always be better than others – and indeed Syed became a world champion, but some of his perfectly ordinary neighbours became county champions purely through hard work and great teaching.

He then talked about how limiting the ‘fixed mindset’ view of talent is. Children who think they are ‘no good at maths’ become disengaged because they will never succeed. But the children born with apparent talent also suffer, and he gave the example of Premier League football academies, who struggle to turn their young players into successful players. The reason, Syed says, is that they work really hard to get into an academy, then when they do get in they decide ‘I must be talented, I got in, agents are waving money and praise at me.’ And talent is supposed to look effortless, so they cannot admit to need practice or to work hard at any of the skills needed to be a great player.

He also said that the trend from the 1970s onwards of lavishing praise on all children, regardless of the quality of their work, was also very damaging. It was a well-intentioned attempt to boost self-esteem, but that kind of self-esteem isn’t worth having, he argued. It’s worthless because as soon as you come up against something you can’t do, you crumble and give up, thinking ‘I wasn’t any good after all’.

If, however, you have a ‘growth mindset’, Syed argued, you do not stop at the first obstacle saying, for example “I’m no good at behaviour management in the classroom, I just don’t have natural authority.” Instead, you think: how can I get better? What literature is there I can read for tips? Can I watch a colleague who does have good behaviour in their class to see what techniques they use? And by this point in the talk I was utterly convinced not only of his case, but also that in many areas I was guilty of having a fixed mindset myself.

Then a man sitting near me asked him “Do you enjoy table tennis?”

It was a great question. He asked it because at no point had Syed mentioned joy. Syed readily acknowledged the importance of joy, but the fact that he hadn’t mentioned it in about half an hour set me thinking. And this is the conclusion I reached: just because I can, with the right teaching and hard work, become good at table tennis / flamenco / calculus / rock climbing / painting – doesn’t mean that I should. Not if I don’t want to. Not if I don’t enjoy it.

Now clearly, some things are more important than others. A child might need to do some things they hate in order to pass some basic exams to get any kind of job. Great teaching can go a long way to inspire, but if it’s something a child fundamentally has no interest in, you are going to have a struggle. And I think that’s probably okay, if – and it’s a big if – the child has at least one thing they are passionate about, one thing they love. And it is the role of teachers to find that thing and draw it out of the child – as in the meaning of the Latin route of the word ‘educate’ – to lead or draw out. Draw out the one thing that brings them joy.

Posted in education | Tagged , , | Leave a comment

J’accuse: Apple killed the podcast

Okay, this isn’t exactly scientific. It’s based on a sample of precisely… 1. Me. But I can’t believe I’m alone. (Okay, my Morrissey A-Level studies tell me that we are all alone and shall be for ever, but you know what I mean).

I’m not stupid. I can write simple Python code, I can assemble (most) Ikea furniture and I can even put music on my phone using iTunes. But I cannot FOR THE LIFE OF ME work out how to use Apple’s Podcast app.

I seem to be able to subscribe to an entire series – which I don’t always want to do – but do you know what? There isn’t enough room on my phone for the entire Wittertainment back catalogue. There isn’t even room to update iOS after a few apps and a few hundred songs.

All I want to do it drag THIS one single podcast onto THAT phone. And I can’t figure out how to do it.

The result is: I stream podcasts. I click on the ‘download’ link and Safari happily plays along. It’s a bit hard to navigate a 2 hour podcast (hello Jason Isaacs) on a tiny screen, so sometimes I have to reload it (helping the download stats, possibly).

Other podcasts offer the opportunity to stream in a lovely embedded player. I listened to the whole of Serial this way. And I suspect a lot of podcast listening is done this way – in web browsers (possibly in the background).

I’d like to hear your experiences. Do you load up your generic MP3 player and jog into the sunset – or for most podcasts, are you streaming and needing a 3G or wifi connection?

Posted in Apple, internet, iPhone, radio | Tagged , , | 1 Comment

A different kind of phone hacking

I previously mentioned this awesome project to rip out the innards of an old rotary dial phone, and stuffing a Raspberry Pi inside which plays a different MP3 file out of the earpiece each time you dial a different number.

I decided to have a go myself, having found 2 old phones in the loft. These are old British Post Office / GPO phones, so the wiring is probably different. I’d also like to keep these phones intact if I can, so I decided to do a bit of probing to see if I could attach a RaspberryPi to the phone’s existing internal terminals.

First – I had to choose a phone. The red one is type 706, the white a newer type 746.

I soon plumped for the white one as its terminals were more accessible and there’s more room inside.

The red one has an extra button and even has a vertical early PCB ‘card’ inside. Following the wires round inside is a nightmare, so I put this one back together and let it be.

I started probing – appropriately – with an old British Telecom multimeter, which was fine for locating the wires for the receiver ‘hook’ (it might be nice to have a dial tone when you lift the handset!), but a multimeter doesn’t react quickly enough to count pulses from the rotary dial. So I made a simple circuit with an LED to test the different terminals inside the phone to see if any were connected across the dial switches – and indeed they were. By breaking the LED circuit, and touching the loose ends across different pairs of terminals and dialling, I could see when the light flickered, showing the dial breaking the circuit to transmit the numbers.

Modern fixed phones dial by sending tones down the line to the exchange – known as DTMF or TouchTone. Old rotary phones worked by breaking a circuit to the exchange creating pulses at a rate of 10 pulses per second. 1 break in a second means you’ve dialed 1, 2 breaks is a 2 and so on. But what about 0?

I’m might confused by the wiring instructions in the original article, so next steps are to look carefully at the code, and perhaps write my own. And buy a jack plug so I don’t have to solder the earpiece on to the Pi direct.

Thanks to my former colleague Frank Bath for information about Strowger telephone dialling, and to James West for reminding me about phone phreaking and an old way you could sometimes cheat a payphone in the UK by tapping the cradle switches to mimic the dial pulses. I used to actually phone people this way on my home phone. Hey, I didn’t get out much, and phone numbers in my village were 4 (FOUR) digits long. And I can still remember my friends’ numbers: 2235 and 3516. And no, they’re not my PINs…

Update

I’ve now wired the earpiece up…

…and I got as far as getting the Pi to detect when I hang up to stop the radio playing.

Posted in nostalgia, Raspberry Pi | Tagged , , , , , | Leave a comment

2 cool RaspberryPi projects

Here are two insanely cool Raspberry Pi projects I spotted this week.

First up, turn a rotary dial phone into an MP3 player. This seems really simple and do-able. James West points out that some telephone EQ on the audio files would be desirable – boost the mid, slice off the top & bottom. The example plays nursery rhymes, and I can see this being a great gizmo to have in a classroom for KS1 children. Personally, I’m tempted to make a modern day Dial-a-Disc phone for my daughter. And if you want to know what Dial-a-Disc was, ask your gran.

Next: Libby Miller does very cool things with Raspberry Pi radios. (I think she may get paid for doing this, in which case she totes has my dream job). For some reason I’ve only just stumbled upon Radiodan, and I’ll be experimenting with this radio prototyping platform as much as my time allows. I love making RaspberryPi radios, and this is so much up my street I can’t believe I didn’t know about this – or perhaps I did and it got lost in the noise. Anyway, Libby’s latest radio uses old Oyster cards to play different podcasts when you present the relevant card to the radio. Wave Mark Kermode at the radio – Wittertainment! Sarah Koenig – get Serial! Totes amaze.

Posted in Linux, radio, Raspberry Pi, Raspbian | Tagged , , | Leave a comment