The amplifier is based on the amp6-basic 2 x 25 W chip amp from 41hz connected to a standard switch mode power supply. It’s supplied only with a mini-jack input since thats what my ipod, phone and mac use anyway. A DACT Type 23 50K stepped attenuator acts as volume control. I put it all together in an anodized aluminum chassis with a thick custom frontplate.

Components laid out

I cut out the various holes in the back and frontplate using regular twist bits and flat wood bits on a column drill. I finished off the non round cutouts using a file. I ended up using a few hours with a dremmel to cut out the frontplate for the volume knob because I didn’t have a wide enough drill bit around. It turned out quite rough but I tried to use it as a design feature engraving the whole frontplate with the dremmel. I also mounted a blue LED as an on-off indicator, with a rather large resistor 13K Ohm to avoid it illuminating my whole room at nighttime.

I supply the amp6-basic with about 14 V which it can easily handle if it’s rather efficiently cooled. I mounted it to an aluminum plate in the side of the chassis furthest from the SMPS with cooling paste on the back of the chip. The power cables are wound around a large ferrite which should in theory reduce the noise.

The expenses add up to around DKK 1500 (~EUR 200). I am using the amplifier with two small Dali speakers and I am very satisfied with the overall sound quality.

Documentation

The slackline is hooked up to a strain gauge that measures the weight on the slackline. An Op-Amp amplifies the signal for the arduino and two pieces of flexible high intensity RGB led strip are controlled with PWM via a ULN2003 Darlington transistor array.

Schematics

Code

// KulturSYDHavn Illutron Interactive slackline code by Johan Bichel Lindegaard

float h;
int h_int;
int r=0, g=0, b=0, intensity=100;
void h2rgb(float h, int &R, int &G, int &B);

// Select which analog input the strain gauge is connected to.
const int mPin = 0;

int m = 0;
int state = 0; // 0: inactive, 1: active, 3: pending inactive
int deactivationThreshold = 8;
int deactivationTime = 1000;
unsigned long stateTimeStamp;
unsigned long stateTime = 0;

// Select which PWM-capable pins are to be used.
const int redPin = 10;
const int greenPin = 11;
const int bluePin = 9;

long brbgPreviousMillis = 0;
long fadePreviousMillis = 0;
boolean blinkState = 0;
boolean fadeUp = 0;

// range calibration variables.
int lowPoint;
int highPoint;

void setup()          
{
  // start serial port at 9600 bps:
  // Serial.begin(9600);

  pinMode(redPin, OUTPUT);
  pinMode(greenPin, OUTPUT);
  pinMode(bluePin, OUTPUT);

  // calibrate
  lowPoint = analogRead(mPin);
  highPoint = lowPoint + 124;
  if(highPoint > 1024) {
    highPoint = 1024;
  }

  // test pins
  rgb(255,0  ,0  ); delay(500);
  rgb(0  ,255,0  ); delay(500);
  rgb(0  ,0  ,255); delay(500);
}

void loop()
{  
    int m = analogRead(mPin);

    // Check calibration, and expand range if needed.
    if(m < lowPoint) {
      lowPoint = m;
    } else if(m > highPoint) {
      highPoint = m;
    }

    // Serial.println(m);

    // keep track of how long the line has been active and inactive
    if(m > lowPoint + deactivationThreshold) {
      if(state == 0) {
        state = 1;
        stateTimeStamp = millis();
      }
      stateTime = millis() - stateTimeStamp;     
    } else if(state == 1){
      state = 3;
      stateTimeStamp = millis();
    } else {
      stateTime = millis() - stateTimeStamp;
      if(stateTime > deactivationTime) {
        state = 0;
      }     
    }

    if(state != 0){

      // Convert input to RGB through hue then output.
      h = ((float)map(m, lowPoint, highPoint, 1024, 0))/1024;
      h_int = (int) 360*h;
      h2rgb(h,r,g,b);

      // if active for a short while enter fancy blink mode then return to normal
      if(stateTime > 15000 && stateTime < 60000) {
        int btime = map(stateTime,15000,60000,1000,50);
        brgb(r,g,b,btime);       
      } else {
        rgb(r,g,b);
      }

    } else {      
      unsigned long currentMillis = millis();
      if(currentMillis - fadePreviousMillis > 100) {
        fadePreviousMillis = currentMillis;

        if(intensity > 99) { fadeUp = false;
        } else if (intensity < 1) {
          fadeUp = true; }         

        if(fadeUp) {  ++intensity;
        } else {      --intensity; } 

        rgb(255,0,0,intensity);   
      }

   }   
}

void rgb(int r, int g, int b) {
  analogWrite(redPin,r);
  analogWrite(greenPin,g);
  analogWrite(bluePin,b); 
}

void rgb(int r, int g, int b, float intensity) {
  if(intensity > 100) {
    intensity = 100;
  } else if(intensity < 0){
    intensity = 0; 
  }

  rgb(r/100*intensity, g/100*intensity, b/100*intensity);  
}

void brgb(int r, int g, int b, int interval) {
  unsigned long currentMillis = millis();
  if(currentMillis - brbgPreviousMillis > interval) {
    brbgPreviousMillis = currentMillis;
    if (!blinkState) {
      blinkState = 1;
      rgb(r,g,b);
    } else {
      blinkState = 0;
      rgb(0,0,0);
    }
  }
}

void h2rgb(float H, int& R, int& G, int& B) {

  int var_i;
  float S=1, V=1, var_1, var_2, var_3, var_h, var_r, var_g, var_b;

  if ( S == 0 )                       //HSV values = 0 √∑ 1
  {
    R = V * 255;
    G = V * 255;
    B = V * 255;
  }
  else
  {
    var_h = H * 6;
    if ( var_h == 6 ) var_h = 0;      //H must be < 1
    var_i = int( var_h ) ;            //Or ... var_i = floor( var_h )
    var_1 = V * ( 1 - S );
    var_2 = V * ( 1 - S * ( var_h - var_i ) );
    var_3 = V * ( 1 - S * ( 1 - ( var_h - var_i ) ) );

    if      ( var_i == 0 ) {
      var_r = V     ;
      var_g = var_3 ;
      var_b = var_1 ;
    }
    else if ( var_i == 1 ) {
      var_r = var_2 ;
      var_g = V     ;
      var_b = var_1 ;
    }
    else if ( var_i == 2 ) {
      var_r = var_1 ;
      var_g = V     ;
      var_b = var_3 ;
    }
    else if ( var_i == 3 ) {
      var_r = var_1 ;
      var_g = var_2 ;
      var_b = V     ;
    }
    else if ( var_i == 4 ) {
      var_r = var_3 ;
      var_g = var_1 ;
      var_b = V     ;
    }
    else                   {
      var_r = V     ;
      var_g = var_1 ;
      var_b = var_2 ;
    }

    R = (1-var_r) * 255;                  //RGB results = 0 √∑ 255
    G = (1-var_g) * 255;
    B = (1-var_b) * 255;
  }
}

Put up a wire for storage, and conceptualized a bit; Wires are versatile, almost invisible when not in use and there is no surface to keep clean of dust. A lot of different shapes can rest on the wires and other stuff can hang from the wire in carabiners.

The most essential parts are from Matuzmaster a retailer in Budapest selling mainly vintage NOS components, the rest is mainly from VeloSolo an English shop specializing in single speed and fixed gear. The wheels and chain are from highonbikes, the brake levers from eBay user angpatten357 and the saddle, tires and improved brake shoes for the front brake caliper from the Danish retailer Bikebuster.

I had my local bike mechanic PH cykler install the bottom bracket and headset since I didn’t have the tools, but the rest I assembled myself.

Here is rundown of the components, where I bought them and for how much.

In the end the total price of components came to kr 6,593.31 and shipping to kr 862.56 leaving the bike with final pricetag of kr 7,455.86. It is not a major bargain considering the ours put into purchasing components and putting it together. However I would not have been able to buy one like it anywhere and the feeling of riding a bike you just put together yourself is priceless.

Our submission aims at uniting the natural properties of bamboo with sophisticated modern construction techniques. High tech equipment and computer simulations should be utilized to analyze the climate, terrain, local materials and weather in order to enable the utmost simplicity and effectivity in the design of the structure. You need not compromise on quality of living or aesthetics in order to value ecology. The project showcases bamboo as a modern construction material with many uses beyond the ‘Tiki Hut’.

Bamboo

Bamboo is an amazing material, its tensile strength is close to that of steel and its compressive strength twice that of concrete. Its hollow structure makes it strong because the equivalent shape filled would simply have more deadweight. Bamboo is interesting because its is one of the fastest growing plants in the world and therefore highly renewable.

Construction

The house is constructed mainly in woven bamboo. Heat shaped construction bamboo creates a solid framework and structural elements of four black bamboo canes each lifts the construction about six meters above ground. In order to avoid moist damage to the canes and to insure a stable and unobtrusive construction the structural elements are mounted in a steel plate and bolted to a concrete pad foundation. The pad foundation has a low impact the environment and is easy to establish in rough and soft terrain.

Climate

The construction is to be build in a tropical climate. Because of the high humidity and temperature it is raised six meters above ground. That way moist damage to the construction is avoided and the breeze can flow through the building. In the woven shape there is plenty of room for insulation to sustain a comfortable temperature and the raised structure casts a shadow beneath the building. This cool shade can be utilized for a terrace or simply a hammock. Outer blinds serves to regulate light and heat from the sun. Windows are made in a special fabric that allow for natural ventilation but keeps out the rain.

The structure is constructed in order to be adaptable to the changes in climate, more insulation can be added and the airflow and light can be regulated.

Cradle to Cradle

The Structural elements can easily be removed from the concrete foundation since it is bolted in place and not hardened. The light woven frame can be removed as panels. The heat shaped framework can be taken apart as independent rips. This allows the construction to be relocated and reused over and over again. The individual elements can also be used for other purposes.

A special thanks to Natalie Mossin neighbour and architect at Building Lab DK for guidance and lending me a library of great architectural books.

With no experience as an architect i have come along way. From believing bamboo resists gravity, to actually understand the materials properties in the real world. I have read a great deal about bamboo, its structural properties and different uses. Bamboo is the steel of nature, and the ways in which it can be used continuously amazes me.

For my project i have worked mainly with woven bamboo. Sophisticated weaving techniques allows you to weave bamboo in all imaginable shapes. For the framework i utilize heat bended bamboo. The structure positioned in the treetops of the jungle is supported by long structural elements of four black bamboo canes connected with steel knobs. The structural elements are mounted in a concrete foundation in order to avoid moist damage to the canes. Several of the elements are inspired by the prototypes presented by Bamboo Lab a research project on bamboo as a building material.

I have tried to investigate more sophisticated ways of handling bamboo in order to showcase its potential as more than a Tiki Hut material but a beautiful element in contemporary architecture.

Bamboo …!

The competition is a great opportunity for me to unite my interest and ideas regarding architecture with my expertise in Second Life. I am looking forward to be a part of it and i am sure i will learn a lot in the process.

Which has very good intentions on how to use Second Life and its community, they don’t fully succeed though because they do not have something to offer the users in return. Therefore the users do not get involved in the project.To look at a case of an ongoing successful presence in SL that manages to build an active user community we investigated Pontiac. Motorati as Pontiac’s presence in SL is named relies on mainly competitions and customization. Users can customize there own vehicles and compete in races organized by Motorati which is of value for Pontiac in the ideas and user involvement they achieve but also just as general marketing.Adlast we looked into how Keystone Buchard and some of the projects he is involved in mannages to use SL. He is a pioneer in using SL in his field which is very relevant for Building Lab DK.

Read and see more at http://archsl.wordpress.com/