Scientist activity for 6th grade: How to make a sun tracker with a servo motor and Arduino

Introduction

Hello! Welcome to our blog.

At Makersgeneration, we provide kids with resources to carry out easy science experiments. We also provide project ideas you can carry out using some electronic kits with Arduino, one of which we will look at in this post.

In today's lesson, we will be learning how to make a sun or solar tracker using Arduino and other electronic components, such as servomotor and Light Dependent Resistor (LDR). Sounds interesting right?!! follow us as we discuss how.

What is a Solar tracker?

A solar tracker is a device that automatically adjusts the orientation of a payload towards the sun. This payload can be anything, but for the sake of this project, our payload will be the solar panel.

A solar panel is a device that converts sunlight into electricity and needs to be constantly facing toward the Sun to get as much energy as possible. But the Sun doesn't stay in one position the whole day: it rises in the East in the morning and sets in the West in the evening. So to capture solar energy throughout the day, we need a solar tracker to continuously track and point our panel in the current direction of the Sun.

Our solar tracker will consist majorly of three components:

Light sensors (LDR) - This tracks the intensity of sunlight from any given direction.
Motors (Servomotor) - This handles the movement of the panel from one direction to the other.
The controller (Arduino) - This is the brain of the system. It takes the readings from the light sensors and then activates the motors accordingly.

Now, let's get busy learning how to make our model of a solar tracker. But first, let's run through the list of materials we will need:

Required materials

Arduino Uno board
1 Servo motor
11 Male-Male jumper wires
Cardboard paper
Pencil
Ruler
Scissors
Glue / Tape
Toothpick (or any round object of similar size like a screw)

Building the Solar tracker

Step 1:

Cut out a rectangle from the cardboard measuring 10x6 inches. This will serve as the base of the tracking system.

Cardboard cutout for the base of the system.

Step 2:

Cut out two other portions from the cardboard measuring 2x6 inches. This will serve as the pillar to hold the solar panel in place.

Cardboard cutout for the pillars to hold the panel in place.

Step 3:

Close to the end of one of the pillars, cut out a horizontal rectangle the size of the servo motor. On the same spot in the second pillar, mark a point to make a hole later.

Make a hole for the servomotor in one of the pillars.

Step 4:

Attach the solar panel pillars to the base cardboard with glue with spacing of 6 inches between them. Add additional cardboard cutouts to the base of the pillars to support as shown.

Step 5:

Next, cut out a square from the cardboard paper with dimensions 5x5 inches. This will serve as a model for the solar panel.

Cardboard cutout for the model solar panel.

Step 6:

Now, let's go into the electronics starting with the LDR connection. Assemble and connect your as shown below:

Actual circuit. (Cover the two sections with tape to avoid short circuit) Replicate this for the other LDR.

Step 7:

Make a hole on two opposite ends of the solar panel cardboard cutout, pass the heads of the two LDRs through the holes then secure the wired sections to the other side with tape.

Step 8:

Adjacent to the sides with LDRs, attach the servomotor in the middle with glue or tape (or both).

The servomotor is attached to the solar panel cardboard cutout.

Step 9:

Make a tiny hole in the pillar that was previously marked with a point and fix a toothpick or screw as shown:

Step 10:

Next, fix the servomotor through the previously cut hole in the pillar (with the motor wires facing away from you), then attach the opposite side of the panel to the screw or toothpick attached to the other pillar. Secure the screw/toothpick to the panel with glue.

Step 11 - Circuit

Let's complete the circuit wiring:

Red wires (5V)
Black wires (GND)
Purple wire (analog Pin A1)
Blue wire (analog Pin A2)
Green wire (Pin 9)

Final assembly of Solar tracking system.

Code

// import servomotor library
#include <Servo.h>

Servo myservo;  // create servo object to control a servo

// select the input pins for the LDRs
int LDR_pin1 = A1;    
int LDR_pin2 = A2;  

// variable to store the values from the LDR sensors
int LDR_value1 = 0;    
int LDR_value2 = 0;  

void setup() {
  Serial.begin(9600);   // initialize serial monitor
  myservo.attach(9);    // attaches the servo on pin 9 to the servo object
}

void loop() {

  // read the value from the sensor:
  LDR_value1 = analogRead(LDR_pin1);    
  LDR_value2 = analogRead(LDR_pin2);   

  // calibrate sensor reading from 0 - 1023 to 0 - 100 (%)
  LDR_value1 = map(LDR_value1, 0, 1023, 0, 100);
  LDR_value2 = map(LDR_value2, 0, 1023, 0, 100);

  // print LDR values (in %) on serial monitor
  Serial.print("LDR_1: ");        
  Serial.print(LDR_value1);
  Serial.println(" %"); 
  Serial.print("LDR_2: "); 
  Serial.print(LDR_value2);
  Serial.println(" %");
  Serial.println("");

  // control servomotor direction according to light intensity
  // edit the LDR values according to the light intensity of your environment.
  if (LDR_value1 > 80){
    myservo.write(150); 
  }
  else if ((LDR_value1 < 40) && (LDR_value2 < 40)){
    myservo.write(100);
  }
  else if (LDR_value2 > 80){
    myservo.write(50); 
  }
  
  delay(1000);
}

Video Demo

If your solar panel is tilting in the direction with the most light, Congratulations you did it!!

Thanks for staying till the end, we hope to see you next time!

If you enjoyed working on this project like I did, keep visiting this platform for more ideas on science at home for kids. In the meantime, you can check out what we have in store for you below:

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