noise drives video

And we made this version where the video runs when Chris bangs on the wall.

You run - movie runs

Chris and Gareth took part in an exhibition in Hastings with a sound table and the Shadow Wall. In a quiet moment we tinkered about and came up with a novel little way of interacting with a movie.

When the user runs the video starts playing. When they stop the video stops. How simple is that?

CA music and imagery

P5 hooked up to SC. CA making binary making pictures making music.

Hear it here:

If you liked that one then try this one too.


Made by Chris and Gareth.

LED Matrix part five

Last update I said we thought we needed capacitors as there seemed to be noisy confusion going on after ten minutes or so. This is not the case. It works absolutely fine we just have to make sure that nobody touchs it.

Because of the "Heath Robinson" aesthetic of loads of wires we have made something which although it works it is slightly less than robust.

So, it works, its done and we will get onto displaying images, hopefully from a webcam, as soon as we've made more headway with the POV soft/hardware.

POV Part Two

Now we've finished the LED display it's on to the persistence of vision stuff. Here is a list of the things we need to learn and experiment with:

Hall Effects - we will be using hall effect switches connected to each spoke containing LED's. The switches will be triggered each time the spoke passes a magnet (in a fixed position). Since the wheel will be spun by hand (and will gradually slow down), we need to do figure out a way of calculating the revolution per minute of the wheel in order to then calculate the LED refresh time.

16-bit LED Driver - More experimentation needs to be done with the LED driver. We've got the shift register part sorted, but we also need to look into the PWM for individual LED brightness.

Circuit board design - Although it looks cool, having lots of wires is not big and it's not clever.

Bike Wheel - Possibly the first thing to do is find a bicycle wheel and figure out how to build a sturdy enough stand so people can spin the wheel.

Since some parts will be spinning and others stationary, we are going to need to look into ways of keeping an electrical connection whilst it's rotating. Two methods are slip rings and rotary transformers.

All of this before July, hopefully.

Servo with and servo without

Here's two little video clips. One has a regular servo which can rotate an attached blade from 0 to 180 degrees, although it appears to be more like 170 degrees. The other clip has a modified servo that will rotate continuosly. The mod was somewhat like this one here.

The centre point of the modded servo is when you send it the number 104 from the serial port. If you send it zero it spins at its maximum rate clockwise and if you send it 180 it spins as fast as it can anticlockwise.

I'm going to run some tests on either 8 or 16 unmodded servos using one or two of the shift registers we used for the LED array in the coming weeks. This is preliminary work for some kinetic sculpture ideas I'm working on. Ultimately I want to go beyond simple reactive sculptures and incorporate more sophisticated behaviours. For now the Arduino boards are great for what I'm doing. The processor on the Arduino board can interpret information from its sensors and then trigger some output. For more sophisticated behaviours I'm thinking I'll need to bring a Gumstix board to be the brains behind the operation.

The artworks that are influencing these avenues of research range from Ed Ihnatowicz's Senster through to more contemporary pieces such as Daniel Rozin's wooden mirrors via work such as Andy Gracie's "Fish, plant, rack"

The AI methods I'm using are those documented by Melanie Mitchell, Andy Clark, David Fogel, and Margaret Boden amongst others as well as the techniques I learned form the Data Mining module I took last term.

With a slimline Unix controlled machine I can implement more powerful machine learning algorithms. By using a combination of modded and unmodded servos I should be able to create sculptures with a somewhat lifelike quality to them.

HELLO WORLD

Well we wired it all up and uploaded our program to the Arduino and lots of LEDs flashed a lot. So much constant flashing that we figured there was a problem somewhere. Somewhere amongst the 5000 solders there was a problem. Or was there?

A closer inspection showed that actually we had two slightly erroneous lines in the Arduino code. The first problem was that the numbers were displaying backwards eg 254 was showing as 11111110 rather than 01111111. The second was the cause of the constant flashing. We were returning the latch pin between readings from the serial port so by moving the line " digitalWrite(latchPin, 1);" out of our loop that runs when there is new data we were able to go flashing free.

There is one small problem still which is that confusion seems to build up over a period of about half an hour but we suspect this is because we haven't used enough capacitors. Thats our next little task before we can start using the LED array for displaying camera imagery.

Check out the video clip for the classic Hello World.