Let’s get Physical! New physical computing animation

With the success of the first two productions from Saladhouse, our animator friends in Manchester (What is a Raspberry Pi? and Setting up your Raspberry Pi), we proceeded to make plans for a third in the series. The topic we chose to cover this time is one which demonstrates the additional power of the Pi in learning – an introduction to the realm of physical computing.


Look through the amazing projects in our blog, the MagPi or Pi Weekly and you’ll see many of them use the portability of the small form factor and low powered nature of the Pi along with the extensibility the GPIO pins give you – not to mention the wealth of community produced add-on boards available making it all much easier.

B+ gpio closeup

Those pins sticking out there. General Purpose Input/Output. Did we mention there are 40 on the B+?

Here at Pi Towers we all love physical projects – from robotics and home automation to flatulence alarms and scaring the elderly – and we believe they’re a great way to introduce young people to coding, computational thinking, product development and understanding systems.

The video refers to some resources for projects you can make yourself. We featured the hamster disco on our blog in July, and you may have heard talk of some of the others on twitter – which are all brand new, constructed and tested by our education team. They are:


And here they are in real life:

Physical computing Foundation style: fart detector, robobutler, hamster cam and grandpa scarer. Yes, they all work :)

Physical computing Foundation style: fart detector, robobutler, hamster cam and grandpa scarer. Yes, they all work :)

See more in our resources section.

Huge thanks to Sam and Scott from Saladhouse for their hard work on this – and also to our voice actors Arthur (son of Pi co-founder Pete Lomas) and Maia! And yes, that’s Eben narrating.

A little gift I brought Dave back from Memphis...

A little gift I brought Dave back from Memphis…


Davespice avatar

I’d just like to add that the reason Ben bought that sign for me is because I wrote the fart detector resource, not because I have a flatulence problem in the office. Lolz

Ben Nuttall avatar

Lies! Haha

Shannon Spurling avatar

Lie detector?

Stewart Watkiss avatar

This is great!

Programming games can be fun, but making something physical is a whole different league on the fun scale.

Until people try programming then they may think it’s something really hard that can only be done by ‘geeks’, but electronics has a reputation for being much harder. Before the Raspberry Pi then that was in somes cases true – creating a physical device to interface to a PC was very difficult.

The Raspberry Pi, with it’s GPIO, and the availability of kits and add-ons has changed all that. It’s made hardware hacking (aka Physical Computing) fun and easy to do!

It would be great to see electronics and physical computing being more involved in schools in the same way that computing and coding is now being incorporated into the school timetables. I know that some schools do already which is great (I’ve met teachers and students involved in Raspberry Pi clubs and Robot clubs in schools), but would love to see this as the norm.

For now the Raspberry Pi and it’s community are at least providing an opportunity for the schools that are taking the initiative in physical computing and those at home and in clubs doing the same thing.

Exciting times!

Pete Lomas avatar

Well said & IMHO spot on!

AndrewS avatar

Well that was novel…

Brilliant :-D

marcincin avatar

In my opinion there is a bug in conception. As I see in datasheet, sensor resistance will increase after “fart” and then voltage between GPIO4 and ground will be lover as before. Voltage will increase between 3,2 sensor’s pins – not between GPIO4 and GND – so GPIO4 will not be changed to HIGH. Please correct me if I’m wrong.
Anyway really nice project.

Davespice avatar

The sensor’s resistance decreases with more air contaminants, thus letting a higher amount of voltage through which tips GPIO 4 from LOW into HIGH. The resistance will go back up as the air clears though, but this can take time and it can be quicker to recalibrate the DAC to a higher value in the meantime.

R_Gtx avatar

The RS Gas sensor links to the Figaro TGS 2600-B00, would not the TGS 2602-B00 (also available from RS) be preferable as it is specifically designed for odorous gases such as Hydrogen Sulphide, which is present in really smelly farts.

Davespice avatar

Yes that one would also have worked however it’s not reactive to Isobutane (a common ingredient in deodorant body sprays). Deodorant sprays provide a polite way to test the fart detector while you’re building it. I think that sensor is perfectly interchangeable with the project though.

Jim avatar

Did we mention, that there are only 26 GPIO pins on the 40 pins GPIO header …

Jim avatar

Great comparison! Both RS and franell didn’t have such a comparison and @raspberrypi.org I didn’t found it :(

Are you sure that the dimensions are correct?
The compute module is a 200pin SO-DIMM, that means 67,6 mm x 30mm, but on the table it is only 62mm
Also the thickness seems a bit less. The pcb has 1 mm, so there are only 2 mm for the components?!

It also seems, that the thickness of the other models only means the high of components on the top side of the pcb.
It ignors the pcb thickness and the soldering of the parts on the bottom side.

Can you proof that?

James Hughes avatar

If there are any mistakes, please PM me and I will update the page.

Scot avatar

The gummy bears must burn!

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