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POWhy does static variable not allow loop() to run?
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  1. POWhy does static variable not allow loop() to run?
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    copied!<p>I am writing code for an lamp that mimics the sun (ie rises and sets according to the real sun).</p> <p>I am trying to use a static variable in the loop in order to keep count of the days since 1/1/12 (the last leap year (366 days)) </p> <p>for some reason, the program only works when the variable is <em>not</em> declared as static, but i need the counter to persist through the iteration of each day. </p> <p>Any help would be much appreciated. Thank you.</p> <pre><code>// Sun Object #define REDPIN 5 #define GREENPIN 6 #define BLUEPIN 3 //#define FADESPEED 480// make this higher to slow down #define FADESPEED 120 void setup() { pinMode(REDPIN, OUTPUT); pinMode(GREENPIN, OUTPUT); pinMode(BLUEPIN, OUTPUT); } void loop() { // daylengths for 4 year's worth of days starting from jan 1 of Great year (366 days) (1/1/2012) int dayLengths[] = {33540000, 33540000, 33600000, // .... // hundreds of values omitted here // .... 33360000, 33420000, 33480000, 33480000}; //2012 = 366 days + day # from jan 1st (in 2013) //starts on 0th day so subtract 1 //ready to go for march 24st @ sunrise // why does it not function when day is static????? static int day = 449; int r, g, b; long start = millis(); for (r = 0; r &lt;256; r++){ analogWrite(REDPIN, r); delay(FADESPEED); } //analogWrite(REDPIN, 255); for (g = 0; g &lt; 230; g++) { analogWrite(GREENPIN, (g*.4)); delay(FADESPEED*2); } long stopped = millis(); long elapsed = stopped - start; //approx // delays (amount of daylight - ( sunrise/sunset time ) // delay(dayLengths[day]- (97200*2)); delay(dayLengths[day]- (elapsed*2)); for (g = 230; g &gt; 0; g--) { analogWrite(GREENPIN, (g*.4)); delay(FADESPEED*2); } for (r = 256; r &gt;0; r--){ analogWrite(REDPIN, r); delay(FADESPEED); } analogWrite(REDPIN,0); //delays (millis in 1 day) - (length of daylight) delay(86400000 - dayLengths[day]); // once 4 year cycle is over, resets day to 0 if (day &lt; sizeof(dayLengths )){ day++; } else { day = 0; } } </code></pre>
 

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