network_rgb.ino

// Adapted from generic web server example as part of IDE created by David Mellis and Tom Igoe.

#include "Arduino.h"
#include <Ethernet.h>
#include <SPI.h>
#include <string.h>
#include <stdlib.h>

#define DEBUG false

// <1>
// Enter a MAC address and IP address for your controller below.
// The IP address will be dependent on your local network:
byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xAE };  
byte ip[] = { <PUT YOUR IP HERE AS COMMA BYTES> }; //eg 192,168,0,100
byte gateway[] = { <PUT YOUR GW HERE AS COMMA BYTES}; // eg 192,168,0,1
byte subnet[] = { <PUT YOUR SUBNET HERE>}; //eg 255,255,255,0

// Initialize the Ethernet server library
// with the IP address and port you want to use (in this case telnet)
EthernetServer server(23);

#define BUFFERLENGTH 255

// these are the pins you wire each LED to.
#define RED 5
#define GREEN 6
#define BLUE 9

#define GND true // change this to false if 5V type, true if GND type light disc
 
void setup() {
  Ethernet.begin(mac, ip, gateway, subnet);
  server.begin();
    
  #ifdef DEBUG
  Serial.begin(9600);
  Serial.println("Awaiting connection");
  #endif
    
}
 
void loop() {
 
  char buffer[BUFFERLENGTH];
  int index = 0;
  
  // Listen
  EthernetClient client = server.available();
  if (client) {
    #ifdef DEBUG
    Serial.println("Got a client");
    #endif
    
    // reset the input buffer
    index = 0;  
    while (client.connected()) {
      if (client.available()){
        char c = client.read();
        // if it's not a new line then add it to the buffer <2>
        if (c != '\n' && c != '\r') {
          buffer[index] = c;
          index++;
          
          if (index > BUFFERLENGTH) index = BUFFERLENGTH -1;
          
          continue;
        } else {
          buffer[index] = '\0';
        }
        
        // get the message string for processing
        String msgstr = String(buffer);

        // get just the bits we want between the {}
        msgstr = msgstr.substring(msgstr.lastIndexOf('{')+1, msgstr.indexOf('}', msgstr.lastIndexOf('{')));
        msgstr.replace(" ", "");
        msgstr.replace("\'", "");
        #ifdef DEBUG
        Serial.println("Message:");
        Serial.println(msgstr);
        #endif
        
        // rebuild the buffer with just the URL
        msgstr.toCharArray(buffer, BUFFERLENGTH);
        
        
        // iterate over the tokens of the message - assumed flat. <3>
        char *p = buffer;
        char *str;
        while ((str = strtok_r(p, ",", &p)) != NULL) { 
          #ifdef DEBUG
          Serial.println(str);
          #endif
          
          char *tp = str;
          char *key; char *val;
          
          // get the key
          key = strtok_r(tp, ":", &tp);
          val = strtok_r(NULL, ":", &tp);
          
          #ifdef DEBUG
          Serial.print("Key: ");
          Serial.println(key);
          Serial.print("val: ");
          Serial.println(val);
          #endif

          // <4>
          if (GND) {          
            if (*key == 'r') analogWrite(RED, atoi(val));
            if (*key == 'g') analogWrite(GREEN, atoi(val));
            if (*key == 'b') analogWrite(BLUE, atoi(val));
          } else {
            if (*key == 'r') analogWrite(RED, 255-atoi(val));
            if (*key == 'g') analogWrite(GREEN, 255-atoi(val));
            if (*key == 'b') analogWrite(BLUE, 255-atoi(val));
          }            
        }
        
        break;
      }     
    }
   
    delay(10); // give client time to send any data back
    client.stop();
  }
}

rgb_cycle.ino

#define RED 5
#define GREEN 6
#define BLUE 9

#define MAX_COLOURS 8

#define GND true // change this to false if 5V type

char* colours[] = {"Off", "red", "green", "yellow", "blue", "magenta", "cyan", "white"};
uint8_t current_colour = 0;

void setup() {
  Serial.begin(9600);
  Serial.println("Testing lights");
  pinMode(RED, OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(BLUE, OUTPUT);
  if (GND) {
    digitalWrite(RED, LOW);
    digitalWrite(GREEN, LOW);
    digitalWrite(BLUE, LOW);
  } else {
    digitalWrite(RED, HIGH);
    digitalWrite(GREEN, HIGH);
    digitalWrite(BLUE, HIGH);
  }
}

void loop () {

  Serial.print("Current colour: ");
  Serial.println(colours[current_colour]);
    
  if (GND) {
    digitalWrite(RED,   current_colour & 1);
    digitalWrite(GREEN, current_colour & 2);
    digitalWrite(BLUE,  current_colour & 4);
  } else {
    digitalWrite(RED,   !(bool)(current_colour & 1));
    digitalWrite(GREEN, !(bool)(current_colour & 2));
    digitalWrite(BLUE,  !(bool)(current_colour  & 4));
  }
  
  if ((++current_colour) >= MAX_COLOURS) current_colour=0;
  
  delay(1000);  
  
}

weather.py

#!/usr/bin/python

# This script will periodically go and check the weather for a given 
# location and return the max and min forecasted temperature for the next
# 24 hours.
# Once this is retrieved it sends a message to a networked arduino in the form
# of an RGB colour map in order to control a light showing expected temps.
#
# Author:   Andrew Fisher <ajfisher>
# Version:  0.1

from datetime import datetime
from telnetlib import Telnet
import urllib2
from BeautifulSoup import BeautifulSoup

# This is specific to melbourne, change it to your location
weather_url = "http://www.accuweather.com/en/au/melbourne/26216/weather-forecast/26216"

# details of your arduino on you network. Change to yours
arduino_ip = "10.0.1.91"

response = urllib2.urlopen(weather_url)

# load this up into beautiful soup
soup = BeautifulSoup(response.read())

# these IDs were discovered by reading the html and gettng to the 
# point where the forecast exists. Use the "next" item
forecast = soup.find('li', {'id':'feed-sml-1'})

# grab the temps and remove the cruft
temp_val = int(forecast.find('strong', {'class':'temp'}).text.replace("&deg;", ""))

print("Forecast temp is %d" % temp_val)

# convert to colour range
if temp_val <= 10:
    red = 0
    blue = 255
    green = 20
elif temp_val > 10 and temp_val <=20:
    red = 128
    blue = 0
    green = 255
elif temp_val >20 and temp_val <= 30:
    red = 128
    blue = 0
    green = 128
elif temp_val > 30 and temp_val <= 40:
    red = 255
    blue = 0
    green = 128
else:
    red = 255
    blue = 0
    green = 0

colour = { "r": red, "b": blue,"g": green }

# Send message to arduino
tn = Telnet()
tn.open(arduino_ip)
tn.write(str(colour))
tn.write("\n")