Tag: sensor

Working through this tutorial currently, trying to understand how Processing can be used to network an Arduino and power the colour of a lamp from words featured in an XML feed (in this case my blog feed – replacing the word ‘love’ with ‘space’ and the word ‘peace’ with ‘rock’). This generates the colour #3C4C2C.

And after adding this post to the feed…
Note the slight colour change.

This is the circuit I used, from this website. The LED is a 4 pin one, which can generate any combination of RGB colour as light:

And the two versions of it that I built:

Here is the code used in Processing:

//Arduino Code for the Arduino Networked Lamp - Processing

#define SENSOR 0
#define R_LED 9
#define G_LED 10
#define B_LED 11
#define BUTTON 12
int val =0; //variable to store the value coming from the sensor
int btn = LOW;
int old_btn = LOW;
int state = 0;
char buffer[7];
int pointer = 0;
byte inByte = 0;
byte r = 0;
byte g = 0;
byte b = 0;

void setup() {
  Serial.begin(9600); //open up serial port
  pinMode(BUTTON, INPUT);
}
  
void loop() {
  val = analogRead(SENSOR);
  Serial.println(val);
 
  if (Serial.available() >0) {
    //read incoming byte
    inByte = Serial.read();
    if (inByte == '#') {
      while (pointer < 6) {
        buffer[pointer] = Serial.read(); 
        pointer++;
      }
      //now need to decode 3 numbers of colors stored as hex numbers into 3 bytes
      r = hex2dec(buffer[1]) +hex2dec(buffer[0])*16;
      g = hex2dec(buffer[3]) +hex2dec(buffer[2])*16;
      b = hex2dec(buffer[5]) +hex2dec(buffer[4])*16;
      pointer = 0; //reset pointer
    }
  }
  btn = digitalRead(BUTTON);
  //check if there was a transition
  if ((btn == HIGH) && (old_btn == LOW)) {
    state = 1-state;
  }
  old_btn = btn; //val is now old,lets store it
  if (state == 1) {
    analogWrite(R_LED, r);
    analogWrite(G_LED, g);
    analogWrite(B_LED, b);
  }
  else {
    analogWrite(R_LED, 0);
    analogWrite(G_LED, 0);
    analogWrite(B_LED, 0);
  }
  delay(100);
}
int hex2dec(byte c) {
 if (c >= '0' && c<= '9') {
  return c- '0';
 } else if (c >='A' && c <= 'F') {
  return c - 'A' + 10;
 }
}

And the code in Arduino:

//Arduino Code for the Arduino Networked Lamp - Arduino

#define SENSOR 0
#define R_LED 9
#define G_LED 10
#define B_LED 11
#define BUTTON 12
int val =0; //variable to store the value coming from the sensor
int btn = LOW;
int old_btn = LOW;
int state = 0;
char buffer[7];
int pointer = 0;
byte inByte = 0;
byte r = 0;
byte g = 0;
byte b = 0;

void setup() {
  Serial.begin(9600); //open up serial port
  pinMode(BUTTON, INPUT);
}
  
void loop() {
  val = analogRead(SENSOR);
  Serial.println(val);
 
  if (Serial.available() >0) {
    //read incoming byte
    inByte = Serial.read();
    if (inByte == '#') {
      while (pointer < 6) {
        buffer[pointer] = Serial.read(); 
        pointer++;
      }
      //now need to decode 3 numbers of colors stored as hex numbers into 3 bytes
      r = hex2dec(buffer[1]) +hex2dec(buffer[0])*16;
      g = hex2dec(buffer[3]) +hex2dec(buffer[2])*16;
      b = hex2dec(buffer[5]) +hex2dec(buffer[4])*16;
      pointer = 0; //reset pointer
    }
  }
  btn = digitalRead(BUTTON);
  //check if there was a transition
  if ((btn == HIGH) && (old_btn == LOW)) {
    state = 1-state;
  }
  old_btn = btn; //val is now old,lets store it
  if (state == 1) {
    analogWrite(R_LED, r);
    analogWrite(G_LED, g);
    analogWrite(B_LED, b);
  }
  else {
    analogWrite(R_LED, 0);
    analogWrite(G_LED, 0);
    analogWrite(B_LED, 0);
  }
  delay(100);
}
int hex2dec(byte c) {
 if (c >= '0' && c<= '9') {
  return c- '0';
 } else if (c >='A' && c <= 'F') {
  return c - 'A' + 10;
 }
}

This didn’t work the first time I ran it, so I had to specify the Arduino port that Processing should use and then…