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.

LED Matrix Part Four pics

We're nearly there. All the boards are soldered, we just need to connect it all up.

LED Matrix part three more pics 2

LED Matrix part three more pics

LED Matrix part three

Another five boards etched. The circuit is printed onto the transfer sheet on a laser printer. The transfer is then ironed onto a sheet of copper backed board. After sawing into five individual boards we drop it all in the etching fluid for a half hour. The boards then need scrubbing (to remove the ink) and drilling.

We've soldered a bunch of the LEDs to wires in readiness for when we get drilling and soldering tomorrow.

POV part one

Another thing we are looking at is persistence of vision. So far we have a prototype that can display fonts on a line of 8 LEDs. Whats needed is a mechanism to move the LEDs but you can see in the photo that it is working. (For the photo the camera shutter was kept open for two seconds and the camera moved.)

LED Matrix part two

Some code has been written to communicate with our as yet unfinished array of LEDs.
We are not sending a long string of ones and zeros but an integer between 0 and 255 which then controls 8 LEDs. If we send 255 then all eight will turn on. If we send 127 then the first one is off while the next seven are on. What's happening is that the shift registers display binary numbers.

So far we have 64 LEDs being controlled. They're being controlled from one pin on the Arduino via eight shift registers. In the next week or so we should have the remaining 576 LEDs wired up.

To date we have designed the PCBs, etched them, drilled the holes and soldered the components on. We need ten of these boards in total which is a lot of etching, drilling and soldering.

Gareth

LED Matrix

Chris and I are making an LED array which will display two colour images from a webcam. Using 80 shift registers we hope to drive 640 LEDs. With a little help from Jon Bird today, we got to grips with the shift register tutorial on the Arduino website. Its pretty straightforward - the idea is that as new data enters it forces the older data down the pipe so to speak.

In the next week or so I'll write some code to communicate with the Arduino board from a PC sending the image as a string containing 640 characters and post it on here. Until then here's a few pics.

Gareth

Arduino Workshop 2

The second Arduino workshop took place over three days in the InQbate room in December 07.

Massimo began by reintroducing us to the Arduino and taking us through some slightly more complex electronics and 'hacking' techniques. We looked at connecting a USB device to the Arduino using the mini USB adaptor and experimented with some LED matrix boards and solar panels.

We went on to look at shift registers and optocouplers and had some opportunity to develop our own small projects. I experimented with making sounds from my Arduino and ended up with a small drum machine.

Chris.

Arduino 2: On Home Ground

Our second opportunity to get to grips with the intricacies of the Arduino; on our home turf and in the most highly charged room in the Northern Hemisphere.
The electromagnetic pulse sent out by the spark that comes off those door handles has been known to stall cars as far afield as Helsinki.
We had the opportunity to look at more sophisticated uses of the boards mixed with Massimo’s refreshingly no-nonsense attitude to “hacking” bits of equipment to produce sophisticated installations out of the electronic equivalents of sticky back plastic and rubber solution glue.
I especially liked the idea of producing a snow board installation for the Italian Winter Olympics out of a usb keyboard chip and a ski game bought from a newsagent.
Henry and I worked on a program that would play a series of random videos that would reconstruct a version of the old Sunday afternoon film “The Cruel Sea”. This would be linked to a heat sensor and then to a coffee machine so that the reconstructed version of the film would reach a climax just as the water was boiling. It isn’t finished yet but it will be installed in the de-bugging room at Sussex and connected to their coffee machine.
We also had the mysteries of the Opto-coupler vouchsafed to us, a mind-bogglingly useful little device that allows you to trip electronic on/off switches via the Arduino board.
Another thorough and fascinating workshop.
Jeremy

and more pics

more pics from December Arduino workshop

December Arduino

Having travelled to London for the last Arduino workshop we had Arduino come to Falmer in the shape of the man himself - Massimo Bansi.

Having covered the basics at the London workshop we were straight into more sophisticated techniques this time. We covered a bunch of topics which included writing to a USB disk directly from the Arduino board, a quick look at Bluetooth comms, the use of optocouplers for hacking consumer electrical goods and an introduction to shift registers.

Jon and I made a prototype low res display from LED boards which could display video or webcam feeds using serial comms from a Processing applet. I'm now working on an enhanced version that uses shift registers. Excellent workshop - if you ever get the chance to attend a small workshop with Massimo be sure to jump at the chance.



Gareth