init commit

README.md

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+# Pointlights
+
+Arduino example code for working with pointlights
+
+For wiring of the LED see the [Arduino Fade tutorial](https://www.arduino.cc/en/tutorial/fade)
+
+

pointlights.ino

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+enum ledStates {INCREASE, DECREASE, STAY, WAVE, OFF, ON}; // Here we make nicknames for the different states our program supports.
+enum ledStates ledState; // We define 'ledState' as type ledStates'
+
+unsigned long startMillis;  //some global variables available anywhere in the program
+unsigned long currentMillis;
+
+int brightness = 0; // our main variable for setting the brightness of the LED
+float velocity = 1.0; // the speed at which we change the brightness.
+int ledPin = 9; // we use pin 9 for PWM
+
+void setup() {
+  // put your setup code here, to run once:
+  pinMode(ledPin, OUTPUT); // set ledPin as an output.
+  Serial.begin(9600); // initiate the Serial monitor so we can use the Serial Plotter to graph our patterns
+  
+
+}
+
+void loop() {
+  // put your main code here, to run repeatedly:
+  compose();
+  delay(10);
+  analogWrite(ledPin, brightness);
+
+}
+
+void compose() {
+  // this is a state machine which allows us to decouple the various operations from timed loops. 
+  // instead we just switch from state to state when particular conditions are met. 
+  
+  switch (ledState){
+
+  case INCREASE:
+    brightness = increase_brightness(brightness, 1);
+
+    Serial.print("INCREASING  ");
+    Serial.println(brightness);
+    
+    if (brightness > 250){
+      ledState = WAVE;
+      }
+    break;
+   
+  case DECREASE:
+    brightness = decrease_brightness(brightness, 0.5);
+    
+    Serial.print("DECREASING  ");
+    Serial.println(brightness);
+      if (brightness == 0){
+      ledState = OFF;
+      }
+     break;
+
+  case WAVE:
+    Serial.print("WAVE  ");
+    Serial.println(brightness);
+    doForMs(5000, wavyshine); // this you might want to do for number of pulses, rather than for duration
+    ledState = DECREASE;
+    break;
+    
+  case STAY:
+    Serial.print("STAY"  );
+    Serial.println(brightness);
+    brightness = brightness;
+    break;
+
+  case ON:
+    Serial.print("ON"  );
+    Serial.println(brightness);
+    brightness = 255;
+    break;
+
+  case OFF:
+    Serial.print("OFF"  );
+    Serial.println(brightness);
+    brightness = 0;
+    doAfterMs(5000, goBackOn);
+    break;
+    
+  
+  }
+}
+
+void goBackOn(){
+  ledState=INCREASE;
+  }
+
+void wavyshine(){
+  Serial.print("WAVE  ");
+  Serial.println(brightness);
+  brightness = sinewave(1000,256,0); // you can tweak the parameters of the sinewave
+  analogWrite(ledPin, brightness);
+  }
+
+int increase_brightness (int brightness, float velocity){
+   return brightness = brightness + 1 * velocity;
+  }
+
+int decrease_brightness (int brightness, float velocity){
+   return brightness = brightness - 1 * velocity;
+  }
+
+int sinewave(float duration, float amplitude, int offset){
+    // Generate a sine oscillation, return a number.
+    // In case you are using this for analogWrite, make sure the amplitude does not exceed 256
+    float period = millis()/duration; // Duration in ms determines the wavelength.
+    float midpoint = amplitude / 2; // set the midpoint of the wave at half the amplitude so there are no negative numbers
+    int value = midpoint + midpoint * sin ( period * 2.0 * PI );
+    value = value + offset; //offset allows you to move the wave up and down on the Y-axis. Should not exceed the value of amplitude to prevent clipping.
+    return value;
+  }
+
+void doForMs(int duration, void (*function)()){
+  // this helper function allows us to execute another function for 'duration' amount of millisecs
+  bool doing = true;
+  startMillis = millis();
+  while(doing){
+    currentMillis = millis();
+    (*function)();
+    if (currentMillis - startMillis >= duration){
+      doing = false;
+      }
+    }
+   
+  }
+
+  void doAfterMs(int duration, void (*function)()){
+  // this helper function allows us to execute another function AFTER a 'duration' amount of millisecs
+  bool doing = true;
+  startMillis = millis();
+  while(doing){
+    currentMillis = millis();
+    if (currentMillis - startMillis >= duration){
+      doing = false;
+      (*function)();
+      }
+    }
+   
+  }