This was a minor project we made during our previous semester. The project used an Atmega328 as the main brains. Apart from tracking the sun in two-axis, the board also had an SD card interface. This enabled it to store the light intensity readings, battery voltage reading and temperature readings from an onboard temperature sensor. The PCB was custom made using the toner transfer method. In order to reduce power consumption, the Atmega328 was used in sleep mode and woken up every hour in order to track the sun. This would increase the efficiency by reducing the current consumption of the setup. I also updated the code to include automatic threshold detection so that the solar tracker can be deployed in any light environment and automatically detect the differences in light intensity.
Here are some pictures of the board :
The board had a 74HC125 level shifter since the SD card worked on 3.3v and the Atmega328 worked on 5v. The header pins were used to connecting 2 servo motors and the inputs from 4 LDRs.
Here’s a picture of the completed project :
We used acrylic sheets for the frame since it was lightweight and could easily support the components. Though we should have used thicker sheets since the once we used tended to bend while the servo motor turned. The base needed to be heavy in order to anchor the whole setup, therefore we used wooden blocks. The board was powered by two 18650 (2200mAH) batteries that would be recharged during the day by the solar panel.