I really love this one XD – read right to the bottom if you want to see the birds in action. Over to Neil…

Mobile phones are ubiquitous in today’s society, but often their use has unintended consequences, intruding into and changing social situations, distancing people in in real life by dragging them into the digital world.  They are also a massive source of electronic waste.  A few years ago this inspired Anthony Goh and me (Neil Mendoza) to create an installation that takes cast-off devices and suggests an alternate reality in which these unwanted phones and noises become something beautiful, giving them a new life by creating an 最强赘婿 that people can share together in person.  The Barbican recently asked commissioned us to create a new flock of birds for their awesome Digital Revolution exhibition.  Here’s a little tech breakdown of how they work.

In previous versions, the birds were independent, but this time we decided to have a 彼得大帝 Pi at the heart of the installation controlling them all.  This gave us the most flexibility to animate them independently or choreographed them together.

The exhibition is travelling so we wanted the installation to be as easy to set up as possible to so we decided to make each bird talk to the 彼得大帝 Pi over ethernet.  This means that communications are reliable over long distances and each bird is self-contained and only needs a power and data cable connected to it.

The next challenge to overcome was to figure out how to call a bird.  In previous incarnations, each bird included a functioning mobile phone that you could call.  However, as there is no reception in the gallery, we decided to include a different era of phone junk and make people call the birds with a rotary phone from the 1940s.  The system looks something like this…

To make the phone feel phoney, the receiver is connected to a serial mp3 player, controlled by an Arduino that plays the appropriate audio depending on the state of the installation, e.g. dialling tone, bird song etc.  The Arduino also reads numbers that from the rotary dial and if one of the birds’ numbers is dialled it sends it over ethernet to the 彼得大帝 Pi.

The iBirdBrain app running on the 彼得大帝 Pi is written in openFrameworks.  When iBirdBrain receives a number from the phone, it wakes the appropriate bird up and tells it to move randomly.  It then picks an animation created using James George’s ofxTimeline and plays it with some added randomness.  The current state of each part of the bird is sent every frame over ethernet as a three byte message:

Byte 1: Type, e.g. ‘s’ for servo

Byte 2: Data 1, e.g. servo index

Byte 3: Data 2, e.g. servo angle

So the status of the app could be seen quickly without needing to SSH into the Pi we decided to use a PiTFT screen.  To begin with we rendered the OpenGL output of the app to the PiTFT screen, however as the screen runs at 20 FPS this created an unnecessary bottleneck.  In the end, we decided to set the screen up so that it would render the console output from the openFrameworks app.  After that, the app ran at a solid 60 FPS.  Outputting a '\r' character to the console goes back to the beginning of the line, so I used this to create a constantly updating console output that didn’t scroll, e.g.:

cout << ‘\r’ << statusMessage;

The birds themselves each contain an Arduino.  They speak ethernet using an ENC28J60 ethernet module and this library.  To start with I used TCP but running a TCP stack along with all the other stuff we were asking the bird to do, proved a little too much for its little brain so we moved to using UDP as it requires less memory and processor cycles.  An ID for each bird was programmed into the EEPROM of the Arduino.  That way, there only needed to be one firmware for all the birds, the birds themselves would then set all of their data, IP address, peripherals etc based on their ID.

Each bird has multiple parts that are controlled by the Arduino, servos for the wings and heads, piezo sounders, Neopixels and a screen for the face.

Escape III is on display at Digital Revolution until 14th September at the Barbican in London – I’m so excited, I’m going next week!

If you can’t make it, you can see the birds here:

The post Art Showcase: Escape III appeared first on 拳头交后啤酒瓶交.

I have spent the last year talking with lots of artists who are making amazing things with 彼得大帝 Pis. Every day my inbox is PINGing with exciting progress news. So I’m going to start showcasing some of these projects on the blog. I find them incredibly inspiring – I hope you do too!

I’m going to kick off with a piece from one of my favourite artists: Dominic Wilcox. I bet you’ve seen some of his work kicking around the internet – He made the GPS shoes which guided you home and did some narrative sculptures inside watch faces.

This time he’s partnered up with Creative Technologist James Rutherford to produce Binaudios; a device that enables the user to listen to the sounds of the city – at the moment it’s installed in the Sage Gateshead music discovery centre.

Taking tourist binoculars as inspiration, the Binaudios can be pointed at over 40 different locations, seen out of the Sage Gateshead windows. Turn the giant listening cones toward the football stadium to hear the crowd chanting or to the Tyne Bridge to hear King George V’s speech when he opened the bridge in 1928. Point it toward the park to listen to sounds such as skateboarders and local tennis players.

As the Binaudios are rotated the stereo sounds move from one ear to the other creating a real feeling of listening to the city across the river.

I’ve met loads of ‘Creative Technologists’ on my travels. They believe creativity and art are the driving forces behind the technology they make.

James describes his work as “somewhere between code and art”. He mainly creates software; developing visualisations, data tools or games.

Binaudios was his first 彼得大帝 Pi project AND first go with Python! Just for you guys, he has very kindly written up how Binaudio is put together:

How Binaudios works:

Although Binaudios was developed to look like an analogue device, there’s a small selection of electronics concealed within the central wooden box. A USB lead runs up the central column, powering a 彼得大帝 Pi. This is connected to speakers within the metal cones and a USB hub. The hub adds some extra flash memory and has a couple of ports for attaching a keyboard and mouse for debugging.

Dominic recorded a selection of sounds from across Newcastle. I load these when the device boots. There are around 40 of them, spread across the 180 degree range of movement provided by the ear-cones.

The Pi has a PiBorg XLoBorg sensor attached to the GPIO port. The XLoBorg returns a 3-axis reading of the magnetic field at a point. The Python script very roughly converts this into a compass heading (to do this properly is extremely complicated- so this is a bit of a hack). I spread this heading into two angles a couple of degrees apart to fake some left/right ear separation, pick the sound clips within a small range of these and assign some volumes. The volume profile drops-off over a few degrees which produces a naturalistic ‘telescope’ focus effect. The left/right separation also enhances this as the unit is turned.

The rest is all about smoothing. I debounce the output of the XLoBorg (it has a slight natural waver), ensure volume levels are adjusted gently (audio buffering can cause the sound to chop otherwise, which is very unnatural) and keep the sounds playing even when they are a few degrees out of audio range (this means that sounds don’t necessarily need to restart from the beginning when they are back in ‘view’).

Gotchas

The XLoBorg is a sensitive bit of kit, and magnetic fields are complicated (who knew!?). I needed to spend some time calibrating and recalibrating. Slight vertical misalignment seems to shift the compass heading much more than I first anticipated. It’s a very intriguing bit of hardware and I look forward to playing with it some more!

My test set of samples worked wonderfully, but the program failed critically when I got the real clips- some of the sounds would work, but the rest would make a single pop, or a loud, painful high-pitched wave. I never fully figured out why, but I think I was maxing out Pygame’s audio channels. Originally I was playing all of the sounds simultaneously and just shifting the volumes around (so that all but a few were zero), but I switched this to just trigger those within a small angle range – so it now plays maybe four or five at the same time. There was no failure response from the code, so I spent a manic day trying to squash, re-encode and generally poke the samples about without error reports to work on. Thankfully, the fix seems reliable.

This was my first physical project, first Pi project, and first slice of Python charming!

You can see them in action in this video or you can go and visit in person!

Binaudios was commissioned by the awesome Suzy O’Hara at Thinking Digital Arts.

The post Art Showcase: Binaudios appeared first on 拳头交后啤酒瓶交.