Solar Tracker

In this project I have made a solar tracker. It will be able to sense the light around it and rotate to directly face the light source so the solar panels have maximum exposure. You then can use the solar panels for whatever application you may need. In this project I just use the solar panels to power an LED.

For this project you will need:

• Arduino Uno
• 2 Light Dependent Resistors (LDR)
• Servo Motor
• 4 AA Betteries
• Some sort of switch
• Solar Panels of choice
• Wires
• Building material (Here I use cardboard)

Some helpful things to have for this project as well would be:

• Ruler
• Multimeter

The first step of this process is to plan what you will be doing. Here I will post a scematic of what the internals will look like and the wiring set up with the arduino, servo and the LDRs.

Also make sure to plan how you will configure your solar panels so they will all connect according to plan, if you want more voltage connect them in series or if you want more current conect them in parallel.

Another tip would be after coding the arduino set up this schematic on a bread board and make sure to test all the parts such as the LDRs, solar panels and other things just to make sure everything is in working order to continue to assebly.

Here you will code the Arduino Uno. I will post my code that I had used for this project and I will elaborate on what it does. Everything about "void loop" is just intial set up and making sure that the code runs properly. It is making sure it runs this will a servo, sets up pins for the arduino and starts a serial output. Then within the "void loop" is where the actual code lies. It is actively reading the signal (voltage) from the LDRs and there it then determines where the servo should turn the solar panels.

You may be asking how the light dependent resistors work this way? Well they work like this; photons from light will strike the material between the conductive materials in the resistor and through some quantum mechanics it allows electrons to flow from one side to another allowing current to flow. But as there is no light on the resistor then it doesn't allow current to flow and resistance goes up. Through this process we are able to sense the voltage drop between the 2 of them and send a signal to the Arduino to turn a certain way to face the light.

I have it also set at 300 ms intervals so the solar panel spins slower, but you may increase the spin rate by lowering that number or vice versa.

I would also recommend that you test your code with the servo and LDR before the next step in this process just to troubleshoot the code if needed. I would set it up on a breadboard for ease of testing as stated in the step before.

For this step it is just to assemble the device. I will post a schematic/drawing of how I assmbled mine, but if you want to get creative and design your own structure you are more than welcome too. I assembled mine out of cardboard, but many other building materials will last longer or be of better quality. Just be careful working with potentially dangerous material or tools to help in this process.

Plan very carefully and be concious of weight distribution within your device so in my scematic I had placed the batteries right above the servo motor. The rest of the components are much lighter than the batteries so if your distribution is off the solar panels will tilt on the servo. To also help combat this make sure to support the servo and create a wide base.

One helpful tip I would suggest also is the set your solar panels at an angle that is about 2-3 degrees less than your latitude to maximize your solar panel coverage from the Sun. There is a scientific explanation for this having to do with the Earth's Orbit around the Sun and your latitiude from the equator.

Here is my final product!