Simple Spark Core firmware for reading temperature from TMP36 and light from an LDR

elapsedMillis.h

/* Elapsed time types - for easy-to-use measurements of elapsed time
 * http://www.pjrc.com/teensy/
 * Copyright (c) 2011 PJRC.COM, LLC
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */


class elapsedMillis
{
private:
	unsigned long ms;
public:
	elapsedMillis(void) { ms = millis(); }
	elapsedMillis(unsigned long val) { ms = millis() - val; }
	elapsedMillis(const elapsedMillis &orig) { ms = orig.ms; }
	operator unsigned long () const { return millis() - ms; }
	elapsedMillis & operator = (const elapsedMillis &rhs) { ms = rhs.ms; return *this; }
	elapsedMillis & operator = (unsigned long val) { ms = millis() - val; return *this; }
	elapsedMillis & operator -= (unsigned long val)      { ms += val ; return *this; }
	elapsedMillis & operator += (unsigned long val)      { ms -= val ; return *this; }
	elapsedMillis operator - (int val) const           { elapsedMillis r(*this); r.ms += val; return r; }
	elapsedMillis operator - (unsigned int val) const  { elapsedMillis r(*this); r.ms += val; return r; }
	elapsedMillis operator - (long val) const          { elapsedMillis r(*this); r.ms += val; return r; }
	elapsedMillis operator - (unsigned long val) const { elapsedMillis r(*this); r.ms += val; return r; }
	elapsedMillis operator + (int val) const           { elapsedMillis r(*this); r.ms -= val; return r; }
	elapsedMillis operator + (unsigned int val) const  { elapsedMillis r(*this); r.ms -= val; return r; }
	elapsedMillis operator + (long val) const          { elapsedMillis r(*this); r.ms -= val; return r; }
	elapsedMillis operator + (unsigned long val) const { elapsedMillis r(*this); r.ms -= val; return r; }
};

class elapsedMicros
{
private:
	unsigned long us;
public:
	elapsedMicros(void) { us = micros(); }
	elapsedMicros(unsigned long val) { us = micros() - val; }
	elapsedMicros(const elapsedMicros &orig) { us = orig.us; }
	operator unsigned long () const { return micros() - us; }
	elapsedMicros & operator = (const elapsedMicros &rhs) { us = rhs.us; return *this; }
	elapsedMicros & operator = (unsigned long val) { us = micros() - val; return *this; }
	elapsedMicros & operator -= (unsigned long val)      { us += val ; return *this; }
	elapsedMicros & operator += (unsigned long val)      { us -= val ; return *this; }
	elapsedMicros operator - (int val) const           { elapsedMicros r(*this); r.us += val; return r; }
	elapsedMicros operator - (unsigned int val) const  { elapsedMicros r(*this); r.us += val; return r; }
	elapsedMicros operator - (long val) const          { elapsedMicros r(*this); r.us += val; return r; }
	elapsedMicros operator - (unsigned long val) const { elapsedMicros r(*this); r.us += val; return r; }
	elapsedMicros operator + (int val) const           { elapsedMicros r(*this); r.us -= val; return r; }
	elapsedMicros operator + (unsigned int val) const  { elapsedMicros r(*this); r.us -= val; return r; }
	elapsedMicros operator + (long val) const          { elapsedMicros r(*this); r.us -= val; return r; }
	elapsedMicros operator + (unsigned long val) const { elapsedMicros r(*this); r.us -= val; return r; }
};

tmp36-ldr.ino

// This #include statement was automatically added by the Spark IDE.
#include "elapsedMillis.h"

elapsedMillis timeElapsed;
unsigned int timeInterval = 5000;

double snsTempF;
double snsTempC;
double snsTempK;
double snsLight;

void setup() {
    Spark.function("getSensor", getSensor);
    
    Spark.variable("snsTempF", &snsTempF, DOUBLE);
    Spark.variable("snsTempC", &snsTempC, DOUBLE);
    Spark.variable("snsTempK", &snsTempK, DOUBLE);
    Spark.variable("snsLight", &snsLight, DOUBLE);
    
    pinMode(A7, INPUT);
    pinMode(A0, INPUT);
}

void loop() {
    if (timeElapsed > timeInterval) {
        snsTempF = getTempF();
        snsTempC = getTempC();
        snsTempK = getTempK();
        snsLight = getLight();
        
        timeElapsed = 0;
    }
}


int getSensor(String command) {
    command.trim();
    command.toUpperCase();
    
    if(command.equals("F"))
        return getTempF()*100;
    else if(command.equals("K"))
        return getTempK()*100;
    else if(command.equals("C"))
        return getTempC()*100;
    else if(command.equals("L"))
        return getLight();
    else
        return -1;
}


int getLight() {
    return map(analogRead(A0), 0, 4095, 0, 100);
}


float getTempC() {
    return (((analogRead(A7)*3.3)/4095)-0.5)*100;
}


float getTempK() {
    return getTempC()+273.15;
}


float getTempF() {
    return (getTempC()*9/5)+32;
}