What’s so great about the Raspberry Pi?

:: Pi, かわいい

Last month I did some travelling in Japan. Although I had a pre-arranged visit in the South for a few days, much of the time my travels across the country resembled a graph drawn as if from the output of a “travelling salesman” algorithm gone wrong. Because—visiting places I’d not been before like Matsumoto, Sendai, and maximising use of the insanely great railway system.

Autumn leaves

Of course, it was just after I left the UK that the Pi Zero MagPi magazine free give-away frenzy started. It wasn’t a surprise that there was such interest; I mean, a new model Raspberry Pi, given away on a magazine cover…

There is a Japanese word which perfectly describes the Pi Zero かわいい (kawaii) - cute and adorable. Is it wrong to describe a computer as “adorable”? For the Pi family, perhaps not.

In 2015 the Raspberry Pi Foundation introduced two new Pi models, the Raspberry Pi 2, Model B ; which has a quad-core CPU and can work as a perfectly respectable desktop computer, and the Pi Zero. If any demonstration is needed to show the intention of the Foundation to provide budding learners and makers in computing with the tools they need; these are it.

Pi Zero board

So what have we got here?

  • the Pi 2, Model B for learning to program in one of the vast variety of languages either installed from the outset on the Raspbian system (Python, Scratch, Ruby {via Sonic Pi - which can also turn you into a live-performance musician} , Wolfram language, Java), or which can be added on with a simple command (Racket, Go, Smalltalk…the list is effectively endless)
  • the Pi Zero for taking prototypes and ideas into the real world of robots, data-collection, and the Internet of Pi 😜. Using the same software that you’ve learned on the Pi 2.
  • a totally fantastic community of makers; people sharing their experiences and advice, resources and an expanding network of manufacturers who provide add-on boards for connecting your Pi to servos, motors, flashy lights etc.

New Year project

For example, a couple of hours of assembling parts and soldering yesterday afternoon, and a similar time this morning tinkering with software yields this indoor/outdoor thermometer, which can respond to commands like:

Thermometer board

> (temp INDOOR)
'(#t 15.4 "2016-01-01T10:52:13")
> (temp OUTDOOR)
'(#t 6.8 "2016-01-01T10:52:52")

with a list of 3 items:

  • a true (#t) or false (#f) indication of whether the sensor transmitted its information correctly
  • the temperature in Celsius
  • the date/time the reading was taken

The code (including comments) is 21 lines long. It happens to be written in Racket, but would be a similar size in Python or Ruby.

The Pi Zero is in a case (also かわいい) which exposes the connections while protecting the board. You can see the indoor temperature sensor—the 3-wire device, and a trailing lead to the identical outdoor sensor. There are only three components needed to construct it, (two DS–1820B temp. sensors and a resistor) plus some connectors. A worksheet on the sensor is available for the CamJam EduKit #2-sensors kit. The nice thing about these sensors is that you can wire several in a simple arrangement for multiple readings.

This project also provided temporary health benefits—it distracted me from that big tin of biscuits which will have to be tidied up before the end of the holiday.

Next steps

The Pi’s software flexibility means that I could install a database to store temperature reading over a prolonged period, plot them in Mathematica (on a Pi 2, model B), or listen to the readings as sounds. Its hardware facilities would allow for, say an alarm if the outdoor temperature dropped below zero. Or above 40C.

Postscript

I have to admit on my return from Japan, I did ask in the airport W. H. Smiths (other newsagents are available) whether they had any copies of MagPi with the Pi Zero still available. I got a slightly weary smile in return. But I did then get one as part of a subscription to the magazine. Result!

Matsumoto castle

Hopefully, this conveys some of my excitement at the current state of the Pi ecosystem, and I’m eager to see what the community makes with the facilities we have available to use, in the coming year.

A Happy New Year to one and all, and tiny Pi Zero (bless)!