Maxwell city soundtrack

Maxwell city day 2-3 8, originally uploaded by hc gilje.

As I promised a year ago in the post about the Maxwell city workshop, I edited together a track using material from all the participants of the workshop into a 20 minutes soundtrack, which was originally made for a radio broadcast for the ctrl_alt_del sound art festival in 2007.
So, finally available, the maxwell city soundtrack.

David Cuartielles´s talk at Piksel

This year´s piksel festival is over, with focus on circuit bending and open hardware solutions. I could only stay the first day, but have been following part of the festival through the quite impressive streams archive from the festival.

I got to see the wonderful loud objects live, which I have written about before.

Last night I watched David Cuartielles from the Arduino team give an interesting talk about the beginning of the arduino project, the current status of the arduino development and challenges ahead. They have sold over 20000 boards, and it has become the standard tool for electronics prototyping. As a result of this position there are now clones being made all over the world, for instance a dual core arduino (!!) made by some people in South-Korea.

He talked about how everything with arduino is open, they only reserve the use of the name arduino. There is quite a big difference between open software and open hardware, as hardware needs to be manufactured so you need some initial investment. They have an interesting strategy for funding new development by letting corporations and institutions paying them to work on the arduino project, so for instance Samsung agreed to let Cuartielles make a lot of board designs which will be available for free soon, without Samsung having any rights to the designs. Some of these boards looked very interesting, like a 32 channel output board (which can be daisychained) with transistors to control lights, motors etc, a 64 channel input board, relay boards etc.

The arduino project is being restructured into a foundation, and some money will each year be used to support people and projects who have problems with access to hardware.

Here is a direct link to his talk (ogg stream).

Connect the dots

mouselab2.jpg, originally uploaded by hc gilje.

I have been very busy preparing and giving a 2 week physical computing workshop at The Academy of Fine Arts in Bergen, “Connect the dots”. It has its own blog, with lots of useful info related to arduino, mice etc. (look for resources category). There are also images available from the workshop.
The aim was to introduce to a mixed group of students the basic concepts of physical computing, and how to to create relations between objects,spaces,actions and people, so it was both a hands on workshop with arduino (analog in/out, digital in/out, serial communication with computer), different sensors, transistors and relays controlling 12 and 220 volt appliances, discussion and presentation of other artists´ work, and the production of a one day exhibition including a listening post, a mouse radio, a paper burning machine, a weather machine and a callstation (where the arduino picks up the phone when you called a specific number ++). Read all about it in the connect the dots blog!

the loud objects

Marius Watz made a nice video documentation of the loud objects performance he attended at monkeytown.

It is a live physical computing concert, where they hook up different sound components on a overhead projector making it interesting also visually.

directional sound

May I Have Your attention, Please, originally uploaded by

I am doing a series of projects called soundpockets for urban interface oslo, which in different ways tries to create pockets of sound in public space. Some of the versions involve the fm sender- mp3 setup mentioned in the previous post, another one involves a directional speaker mounted on a pan/tilt unit, and this has been my second headache this summer, finding a controllable pan/tilt unit which is reasonably fast, which can handle a load of a few kilos and which is not ridiculously expensive.

Fortunately I have had good help from Soundscape studios. The first ideas was to use a existing movinghead light and refit it with the speaker, but it turned out that the motors wouldnt be able to handle the load. Pan tilt units are usually made for a specific purpose, either light or video, and the few ones which are available for general purpose use and which are controllable are very expensive.
The one we have ended up with is quite expensive, but is controlled using serial protocol, is made for outdoor use, and is powerful enough to handle video projectors (for later projects). It is also very fast, up to 300 degrees per second pan, and 60 degrees per second tilt. Hopefully it arrives next week.

The most ambitious plan is to control it using an arduino microcontroller, which will also control a serial-controllable mp3 player, the daisy, so I should be able to place sounds quite accurately in a space, and also create movements with sounds.
If time runs short I will use a macmini with max controlling the sound and pan-tilt unit over the serial port.

I have been testing two different models of directional speakers which uses ultrasound as the carrier signal, I will probably have to go for the smaller one, although I am a bit worried it will disappear in the ambient sound. It is also challenging to find the sounds which works best, and also how to deal with the sounds both coming directly from the narrow beam of the speaker but also the reflections on surfaces in the space.

The inspiration for this projects comes from when I studied in Trondheim in the 90ies, and I heard some stories about how a directional speaker had been used to cause a certain distress on a bridge over the local river: A person walking alone across the bridge suddenly hearing whispering voices. An out of tune clarinet projected into a marching band playing on the 17th of may (Norway´s national holiday).
If these stories are true or not, doesn´t really matter, it is the idea of having a private experience in a public space which intrigued me.

solar energy + fm sender + mp3 = #$!#%!

solar charger posing at helgøya, originally uploaded by hc gilje.

Summer has seen few posts, but not because of lack of activity. I have been busy researching for the upcoming urban interface oslo exhibition. One of my challenges has been to find a setup with a short-range fm sender, a mp3 player and a solarcell/battery solution that would make it possible to place this unit anywhere and leave it running. This has proven a lot harder than I would have imagined.
First, there are now so many fm senders available, and it is really hard to distinguish good from bad (90 % bad), and the reviews out there are not trustworthy. There also seems to be so many factors affecting signal strength so the same sender might appear to have a strong signal one day and a really weak one the next day. Frustrating and time consuming, and I am still checking out different modules.

I guess I should ask Raghav Mahato in India, who claims to have built a radio sender for just over 1 usd.

I knew very little about solar power solutions before this summer, and the options range from build it yourself solutions to “how to survive after a nuclear attack” systems. I looked first at relatively new products advertised as solar chargers for mobile devices like ipods, cellphones and pdas.
Most of these mobile solar chargers combines small solar panels with an internal rechargeble battery with different types of breakout plugs.
Not all of them are able to provide power while charging, which was necessary for my setup. I gave the freeloader a try as it sounded like the perfect companion for a fm sender and mp3 player, it has a 2100 mAh battery, but the results were very disappointing. I guess the current from the solar panels is just too weak to provide enough power to keep the battery charged while in use.
There are not so many other ready-made solutions, either they have a smaller capacity than the freeloader or they are just chargers (so the batteries can´t be used while they are being charged).
I am now looking at more heavy-duty solutions, 6-15W solar panels in combination with a charge controller and a lead battery, but this becomes quite expensive and heavy. And all I need is about 100-150mAh. I am still hoping for the perfect solution to pop up.

This research  will also be useful when looking for selfpowered xbee solutions. They seem to have had success with a solar powered xbee system at ITP.
I managed to do a little bit of work with the Xbees a few weeks ago, finally getting the directmode (connect a input of one xbee to the output of another xbee, without using an external microcontroller) to work, and also exploring the sleep options, which means being able to keep the power used to a minimum.

I have discovered lots of interesting alternative energy websites, here are a few of them:

otherpower, gotwind, cirkits links, altenergystore

rantings from the lab

size matters, originally uploaded by hc gilje.

I have wanted to work more with the Xbee radios, but found out a few weeks ago that the ones I bought had old firmware from 2006 (even though I bought them in late march 2007).
This means that some features are not enabled, like connecting the input of one xbee to another xbee´s output (wireless) without the use of a microcontroller.
To update the Xbee´s firmware you have a few options: the expensive developer boards from maxstream, the DIY hack from Rob Faludi, or the xbee usb dongle from New Micros.

I chose the last option, because I thought it could be useful when including the xbees in a computer network for later projects. This turned out to be a very expensive solution. The dongle itself is only usd 39 which is not too bad. The problem is that New Micros doesnt specify shipping costs when you order, they just add it to your bill when it ships. I specifically asked them to send me a quote of how much the shipping would be, but they didn´t. I chose Fedex economy from the available choices, assuming it would be relatively fast and not too expensive. Well, I was wrong. They charged 71 usd for shipping and handling for a device the size of my thumb. And when I received the package I realized why it was so expensive: They shipped it in a pizza-delivery box filled with styrofoam, where the styrofoam pieces were bigger than the dongle, making it hard to even find it in the box.
Lesson learned: If placing international orders, don´t go for shops which don´t tell you the shipping costs when you place the order. Fedex, I didn´t order a pizza!
Do it the “hard” way: buy a hex inverter and follow Faludi´s tips here.
And, for uploading new firmware you need to do it from a computer with Windows.
Tomorrow I will find out if the dongle does what it is supposed to do.

From the lab: ID-12 RFID reader

ID-12 RFID reader to bluetooth, originally uploaded by hc gilje.

(More images of ID-12 in the lab here)

I have had the chance to work with the ID-12 RFID reader for a couple of days. It is very small, very cheap and easy to use. I have tested it connected to a arduino microcontroller, to a computer with a usb-serial adapter and wirelessly to a computer with a bluetooth modem.
You can find a code example for maxmsp + schematics on how to hook up the reader here.


The Aleph installation reminded me of the installation Cloud that David Rokeby recently completed.

Cloud is a monumental kinetic installation hanging suspended in the Great Hall at the Ontario Science Centre. One hundred identical sculptural elements, arranged in ten by ten grid, are rotated at slightly differing speeds by computer-controlled motors. The elements slowly shift in and out of synchronization. When the motors are just out of sync, huge waves ripple across the space. When completely in sync, the work appears almost solid then suddenly almost invisible. When far out of sync, the sculptural elements float in apparent chaos. “


IMG_9884, originally uploaded by we-make-money-not-art.

Aleph is a kinetic reflection display system by Bengt Sjölén and Adam Somlai-Fischer. A matrix of motorized mirrors.

Read more at we-make-money-not-art or directly at the aleph website