# Dual axis Tracker + Solar panel + Step-up Step-down voltage regulator + charging module.

#### darkieboy

Joined Apr 8, 2019
9
Hi!
This is kindda urgent, because I have contest in a week and my project is...yes..not working so far..

What I want to do:
I want to control the solar panel with 2 servo motors and 4 photoresistors. With the help of the photoresitors, I will make the servos follow the point in which the light is perpendicular on the solar panel.
What i want to do next, is to connect the solar pannel to the voltage regulator and get a constant 5V output. With that output i will supply the charging module that will help me charge a li-pol battery.

What I am using:
0. Arduino Uno
1. Solar panel of 6V with ~ 0.6A - it dint came with that charging cable(https://www.evita.lt/en/p-0040s-saules-baterija-ikroviklis-6v-3-5w-su-usb-lizdu-gh165x135)
2. Step-up Step-down voltage regulator( https://www.pololu.com/product/2119)
3. 4 photoresitors
4. 2 SG-90 Servo Motors(https://servodatabase.com/servo/towerpro/sg90)
5. MicroUSB charging port(https://www.amazon.com/XCSOURCE-Lithium-Battery-Charger-TE420/dp/B01DRT4PWY/ref=sr_1_2?keywords=arduino+battery+charger&qid=1557299298&s=gateway&sr=8-2)

The things i struggle with:
1. Photoresitors and servos
I cant make the photoreistors have almost the same value when the light is perpendicular on them. I bought lots and i cant find more than 3 that are simillar.If i fixx this issue in the soft, it will be very bad when the light is changing its direction. Any ideas?
2. My voltage regulator
It outputs 5V if the input voltage is greater than 2.7V(which i can get most of the time from my solar pannel)
I do not know how to connect the solar panel to this voltage regulator so i can make it work properly. This is how the back of my solar panel looks like
I also connected 2 more wires where i think the GND is(in the center), but i don t quite know if I need them or not.
If i connect a voltmeter between the red and black wires i get the output of the soler pannel, depending on the linght(0 to 5.8V at max)
I connected the voltage regulator VIN pin to the 3.3V on Arduino, GND to GND on Arduino, and VOUT to the voltmeters + and another GND from Arduino to the voltmeter`s - and I have got 5.1V, which means that the regulator is working.
Sorry if I made gramatical mistakes.
Thank you!