source: de.wigbels.avr/sketchbook/hothotheat/hothotheat.pde @ 86f2c9a

/*
 * HotHotHeat
 *
 * Compile with the Arduino IDE (http://arduino.cc); is deployed against a 
 * Atmel Butterfly - so you also need the Butteruino project
 * (http://code.google.com/p/butteruino/)
 *
 * ...will
 * 1) Read the Butterfly temperature sensor and output
 * the result permanently to UART.
 *
 * 2) Read a reed sensor and output
 * the result permanently to UART
 *
 * Contact: Norbert Wigbels
 * (http://foobla.wigbels.de/uber-foobla/)
 *
 * Format: <# of Sensor> <data>
 * Example: 1  23.4
 *          2  HIGH
 *          3  14
 */
 
#include <butterfly_temp.h>
#include <pins_butterfly.h>

#include <LCD_Driver.h>
#include <timer2_RTC.h>


int inputReed = PBPIN4;
int outputLED = PBPIN7;

int value = 0;
int debounce = 0;
int slewRate = 0;
int everySecond = 0;

unsigned long gasReeds = 0;
int  temp = 0;


void setup() {
  LCD.prints_f( PSTR( "HOTHOTHEAT" ) );
  delay( 2500 );
 
  // Set up the RTC timer to call the secTick() function every second.
  RTCTimer.init( secTick );
  
  Serial.begin( 9600 ); 

  TempSense.overSample = true;

  pinMode( inputReed, INPUT );
  pinMode( outputLED, OUTPUT );
  
  digitalWrite( outputLED, HIGH );
}


void secTick()
{
  LCD.print( gasReeds );
  LCD.print( " G " );
  LCD.print( temp );
  LCD.println( " C" );
  everySecond=1;
}


int getSamples() {

  temp = TempSense.getTemp( CELSIUS );
  
  // switchtime of reed is 18 ms including debouncing...
  value = digitalRead( inputReed );
  delay( 20 );
  debounce = digitalRead( inputReed );

  // Reedcontact = Sensor 2
  if ( value==debounce ) {    
    if ( value == HIGH ) {
      slewRate=1;
      return 1;
    }
    else {
      if( slewRate==1 ) {
        slewRate=0;
        gasReeds++;
      }
      return 0;
    }
  }
}


void loop() {  
  // LED marks Butterfly working; dark to mark a reed contact
  if( getSamples()==1 ) {
    digitalWrite( outputLED, LOW );
  } else {
    digitalWrite( outputLED, HIGH );
  }

  if ( everySecond==1 ) {
    everySecond = 0;

    // Temperature
    Serial.print( "1" );
    Serial.print( "\t" );
    Serial.println( temp );

    // Reed HIGH or Low  
    Serial.print( "2" );
    Serial.print( "\t" );
    if( slewRate==1 ) {
        Serial.println( "HIGH" );
    } else {
        Serial.println( "LOW" );
    }
  
    // Total of Gas Reeds
    Serial.print( "3" );
    Serial.print( "\t" );
    Serial.println( gasReeds );
  }
   
  delay(50);
}