How To Build A Portable Solar Tracker

<p>/*<br>  This program will allow the solar panel to track the sun, and drive the actuator using
  pwm. Readings from two photoresistors will be taking from each side of the solar panel.
  A number of samples will be taken, and a average reading will be calculated in order
  to determine which side has a higher sunlight intensity. The linear acutor will then
  either extend or retract to angle the solar panel so it is facing the sun. 
  A reset function is implemented so it will move the solar panel to its defult position.
  This allow the solar panel ready to charge in the morning after remain stationary during
  night time.  </p><p>  Hardware used:
                 1 x Arduino Micro
                 1 x WASP Motor Controller
                 1 x PA-14-6-150 Linear Actuator
                 2 x Photoresistors
                 2 x 7k ohm Resistors
*/
/*
            SERVO LIBRARY 
            
   Include the Servo library and create the servo object.
*/</p><p>#include 
Servo myservo;                                        // Create servo object to control a servo</p><p>/*
            PIN ASSIGNMENTS 
            
   Assign pins from WASP Controller and Arduino Micro to appropriate variable.
*/</p><p>const int WASP_Power = 10;                           // Assign pin 10 to Power for the WASP controller
const int WASP_Ground = 11;                          // Assign pin 11 to Ground for the WASP controller
const int sensor_west_pin1 = 7;                      // A7 pin 6 sensor input 1 west
const int sensor_east_pin2 = 8;                      // A8 pin 8 sensor input 2 east</p><p>/*
            VARIABLE DECLARATION
             
   Delcare variable that will be used in the functions later and initilize them.
*/</p><p>int sensor_west[10];                                 // 10 sample readings from sensor on the west side
int sensor_east[10];                                 // 10 sample readings from sensor on the east side
int reset_counter = 0;                               // Time counter for resetting the solar panel position
const int sample_time_interval = 10000;              // Change this value to set the interval between each sample is taken (ms)
const long solar_panel_adjustment_interval = 600000;  // Change this value to set the interval between each adjustment from the solar panel (ms)</p><p>void setup()
{</p><p>/*
            SET INPUT & OUTPUT 
            
   Set the input and output to the variables and pins.
*/</p><p>  myservo.attach(9);                                 // Attaches the servo on pin 9 to the servo object
  pinMode(WASP_Power, OUTPUT);                       // Set Power to output
  pinMode(WASP_Ground, OUTPUT);                      // Set Ground to output
  digitalWrite(WASP_Power, HIGH);                    // Set 5V to pin 10
  digitalWrite(WASP_Ground, LOW);                    // Set GND to pin 11
  pinMode(sensor_west_pin1, INPUT);                  // Set sensor west pin to input
  pinMode(sensor_east_pin2, INPUT);                  // Set sensor east pin to input
}</p><p>void loop()
{
  
/*
            SENSOR READINGS
            
   Take 10 sample readings from both sensors, and take the average of the inputs.
*/</p><p>  int solar_input_west = 0;                                     // Sun light intensity readings from sensor west
  int solar_input_east = 0;                                     // Sun light intensity readings from sensor east</p><p>  for( int i=0; i<10; i++)
  {   
    sensor_west[i] = analogRead(sensor_west_pin1);              // Taking the analog readings from sensor west
    sensor_east[i] = analogRead(sensor_east_pin2);              // Taking the analog readings from sensor east
    solar_input_west = sensor_west[i] + solar_input_west;       // Sum all the inputs from sensor west
    solar_input_east = sensor_east[i] + solar_input_east;       // Sum all the inputs from sensor east
    delay(sample_time_interval);
  }</p><p>  solar_input_west = (solar_input_west) / 10;                   // The the average of input signals from sensor west
  solar_input_east = (solar_input_east) / 10;                   // The the average of input signals from sensor east</p><p> /*
            SOLAR PANEL MOVEMENT
            
   The solar panel will tilt toward west if the sunlight intensity detected on the west side of the panel is greater than the
   one detected on the east side. The solar panel will tilt toward east if the sunlight intensity detected on the east side
   is greater than the one detected on the west side. However, if the readings from both side are similar, the solar panel
   will remain stationary.   
*/</p><p>  if( solar_input_west - solar_input_east > 20)                // If the sunlight intensity is higher on the west side of the panel
  {
    myservo.writeMicroseconds(2000);                           // Full speed forwards (2000) signal pushing the solar panel to the left(west)
    delay(500); //0.5 seconds  
    reset_counter = 0;
  }
  
 else if( solar_input_east - solar_input_east > 20)           // If the sunlight intensity is higher on the east side of the panel
  {  
    myservo.writeMicroseconds(1000);                          // Full speed backwards (1000) signal pulling the solar panel to the right(east)
    delay(500); //0.5 seconds  
    reset_counter = 0;
  }  </p><p>  else                                                        // If ther sunlight intensity is similar from both side of the panel
  {
    myservo.writeMicroseconds(1520);                          // Stationary (1520) signal stop the solar panel from moving
    reset_counter++;
  } 
  
 delay(solar_panel_adjustment_interval);                      // Delay before another adjustment will be made</p><p>/*
            OVERNIGHT POSITION RESET</p><p>   If the solar panel will be used overnight, the controller will detect the panel remained stationary for more than 10 hours,
   It will then reset the solar panel to its default position facing east.
*/
 
 if( reset_counter > 60)                                     // After the solar panel remained stationary for more than 10 hours, it will move to its default position
  {
    myservo.writeMicroseconds(1000);                         // Full speed backwards (1000) signal pulling the solar panel to the right(east)
    delay(12000); //12 seconds
    myservo.writeMicroseconds(1520);                         // Stationary (1520) signal stop the solar panel from moving
    delay(500);  //0.5 seconds   
    myservo.writeMicroseconds(2000);                         // Full speed forwards (2000) signal pushing the solar panel to the left(west)
    delay(1000); //1 seconds  
    reset_counter = 0;
  }
}</p>