Wednesday grab bag

Christmas presents

Apparently, it’s the most wonderful time of the year. We have been thinking about what to get for the Raspberry Pi owner in your life. Happily, MakeZine have done the hard work for us, and have come up with a terrific gift guide. Head over and check it out – once, of course, you’ve stopped by our own store and bought your Raspberry Pi fan a branded t-shirt, lovingly hand-knitted from Santa’s beard hair by elves*. All profits on the shirts go to support the charitable work of the Raspberry Pi Foundation.

*Details about t-shirt production may or may not be strictly speaking true.

Baby monitor

Here’s something I’ve been hoping one of you would produce for a while now. If you’ve got kids, you’ll know that many baby monitors are disgustingly expensive bits of kit, whose price remains as high as it is in a pretty unpleasant bit of exploitation of the fear and worry that every new parent experiences. So I was really pleased to see Matt Kaar, a Pi owner from Virginia, make his own networked, high-fidelity monitor from a Pi and a USB microphone. He’s very pleased with the results: “You can hear a pin drop.” You can follow Matt’s detailed instructions on his website if you’d like to make your own. (Thanks very much for responding to my request to write about it, Matt!)

These are all the parts you’ll need to make your own. Matt says the whole setup was “easier than I’d thought” – this is a project that even beginners will be able to approach.

I’m sure that once the $25 camera board is released in the new year we’ll start to see some cheap camera monitors being hacked too.

Plan 9

We’re very pleased to see that Plan 9 has been ported to the Pi. Plan 9 is an open-source Unix-type operating system, which was originally developed at Bell Labs as a research OS. What’s particularly interesting about Plan 9 is that everything behaves like a file, whether it’s a local or a network resource. We recommend you have a play with it!

Glenda, the Plan 9 bunny

You can download an image for your SD card, alongside documentation and a pdf newbie’s guide.

Raspberry Pipboy

More than a year ago, people on our forums started talking about using the Raspberry Pi in a very specific piece of cosplay. If you’ve played Fallout, you’ll know that no self-respecting apocalypse survivor goes anywhere without her Pipboy. People were wondering whether a Raspberry Pi could be used to drive a working piece of costume, perhaps with a GPS, and definitely with a small screen and lots of blinkenlights.

I thought that particular thread of conversation had died quietly: I was wrong. Ryan Grieve  has made a really nice example using a car reversing panel, a tub of polymer pellets, a handful of leds and an Adafruit cobbler.

His Pipboy has functionality including a world map, local map, radio and a twitter client – or at least it did before some shonky home-wiring caused the whole arrangement to burst into flames. Happily, the Pi survived, and photos were taken before the disaster. Ryan also has code so you can put your own together – just please be more careful with the wiring if you make one yourself. Electricity’s not a toy, kids.

Good luck in fixing her back together, Ryan! We congratulate you on your flameproofness.


Here’s a project with a more practical application. Gasser is a Pi-based, networked, mobile pollutant sensor for detecting nitrogen dioxide, ozone and sulphur dioxide, developed in Paris.

Gasser v2 prototype

This self-contained unit’s BOM cost comes in at €255 (the majority of that cost is taken up by the very accurate sensor); this is cheaper and smaller than equivalent devices – and it’s still only a prototype! We wish LaboCitoyen all success with the project; it’s great to see a Pi being used to make our cities healthier places.


Like Raspberry Pi? Like 3D printing? Like biscuits? (OK, Americans: cookies.) This Thingiverse cookie cutter pattern from Tesla’s Moustache also comes with a recipe to make your own dough.

Learn about relays

Alex from has some video to show you how to use relays to turn what he calls “useful, real, BIG things” like fans and lamps on and off, according to environmental conditions – too hot and the fan will turn on, too dark and the lamp will turn on. You can also hook the devices up to the network, so you can use a connected device, like your phone, to turn them on and off; and just because he can, Alex has also added some sound effects. This is a great tutorial. If you’re interested in learning about physical computing, it’s well worth watching this video and reading Alex’s blog post. has plenty of other fun tutorials – I recommend you spend a few minutes browsing through the collection!


Finally, here’s a project to use up some of the LEGO you’ve been asking for for Christmas. Tom Rees has instructions on building a remote-controlled LEGO car, steered with an Xbox controller.


alex avatar

Thanks for the mention Liz :)
Richard Miller did a demo of Plan 9 for the Pi last week at the Oxford Jam. I’ve got some video I haven’t had a chance to do anything with yet. (I’ll see if I can change that soon.) He recompiled the kernel for us and it took just 1 minute. Impressive in its simplicity and power.

liz avatar

Oh, that’s cool – if you do end up sticking it on YouTube, give me a shout and I’ll see about putting it up here. Thanks!

Montekuri avatar

[quote]His Pipboy has functionality including a world map, local map, radio and a twitter client – or at least it did before some shonky home-wiring caused the whole arrangement to burst into flames.[/quote]
So, that Pipboy would be calle Pi ARM Burner :D

David Gillies avatar

The baby monitor thing points out a very useful feature of SSH: if you have a ‘producer’ process (i.e. something that writes to stdout) on one side of a connection and a ‘consumer’ process (i.e. one that reads until EOF from stdin) on the other then they can be chained together. If ‘producer’ is the source process and ‘consumer -‘ is the sink process reading from stdin then they can be linked thus:

me@local:# producer | ssh user@host consumer –

Michael Kellett avatar

The Learn about Relays item links to an article which suggests some very unsafe use of mains voltages. Any one building the device suggested runs a real risk of serious injury or death. We don’t want the ranks of RPiers reduced by accidents – so please at the very least add amassive warning to this item. As a general rule you should never use DIY electronics to interface an RPi to mains unless you either use a properly certified ready made interface or REALLY know what you are doing.

Dave Court avatar

Especially since it’s easy to use something like Raspberry Strogonanoff ( to control off-the-shelf hardware that means you never need to go near the high voltages.

Ianc avatar

Won’t someone think of the children! The bottle of Glen’s vodka is wholly inappropriate for a website promoting a product aimed at children. Please buy some decent vodka but not Glen’s.

liz avatar


dagodave avatar

hello from a very cold n wet Wales has a any one done anything associated with astronomy or telescopes would seem a an area for astrophotography as well dagodave

clive avatar

Not seen anything specific, but there’s been quite lengthy discussions about just that over in the forums IIRC

Here’s one
And another one (there may be more :))

Cathy avatar

Cool! Thumbs up to the DIY baby monitor. :)

Comments are closed