Christmas lights fading

christmas_lights.ino

/*
 Christmas lights fading example

 The analogWrite() function uses PWM, so if
 you want to change the pin you're using, be
 sure to use another PWM capable pin. On most
 Arduino, the PWM pins are identified with 
 a "~" sign, like ~3, ~5, ~6, ~9, ~10 and ~11.
 */

#define CUSTOM_SETTINGS
#define INCLUDE_SLIDER_SHIELD

/* Include 1Sheeld library. */
#include <OneSheeld.h>

int ledsPin = 9;       // the PWM pin for the led lights
int greenLedPin = 10;  // green led example
int photodiodePin = 0; // define a pin for Photo resistor

void setup() {
  // As stated in Arduino UNO board, it has only 1 Serial UART 
  // communication peripheral which are the pins 0 (Rx) and 1 (Tx)
  // which are also occupied by 1Sheeld, so they aren’t used when
  // 1Sheeld is adjusted on Uno. In case you need to use the UART 
  // peripheral with another device connected to 1Sheeld, you can 
  // use software serial mode.
  //Serial.begin(9600);

  // OneSheeld setup
  OneSheeld.begin();

  pinMode(ledsPin, OUTPUT);
  pinMode(greenLedPin, OUTPUT);
  pinMode(photodiodePin, INPUT);
}

int light = 210;
int set_point = 0;

int brightness = 10;   // how bright the LEDs are
int fade_amount = 5;    // how many points to fade the LED by

int slider_value = 210;

void loop() {
  light = analogRead(photodiodePin);

  // get the slider value and output it as PWM
  // slider_value = Slider.setValue(set_point);
  analogWrite(greenLedPin,255 - set_point);

  if (light < 200)
  {
      set_point = brightness;
  }
  else if (light > 220)
  {
      set_point = 0;
  }
  analogWrite(ledsPin, set_point);
  
  brightness = brightness + fade_amount;
  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 8 || brightness >= 255) {
    fade_amount = -fade_amount;
  }
  // wait for 30 milliseconds to see the dimming effect
  delay(30);
}