A Mini Heliostat

This project page describes how to make a sun-tracker (heliostat) using a solar panel, current sensor, servo, and some other parts.


  • laser cut acrylic parts
  • plastic flanged bushing (3/8" inner diameter, 1/2" outer diameter)
  • solar panel from kid wind
  • Grove micro servo
  • 4 x M2 x 8mm screws and nuts
  • 4 rubber feet
  • 12 x #6 x 0.5" screws and nuts


  1. Peel paper off the laser-cut parts.
  2. Insert the plastic flanged bushing into the appropriate acrylic part. If you have trouble, flip the acrylic part (holes in laser cut parts tend to be tapered).
  3. Attach the servo using M2 screws and nuts.
  4. Mount the servo attachment (servo horn) onto the appropriate acrylic part using M2 screws and nuts.
  5. Attach the solar panel using #6 screws.
  6. Place rubber feet on the bottom of the large bottom plate.
  7. Finish assembing the structure using #6 screws and nuts.
  8. Send the heliostat sketch to your Arduino using the programming tool.


Try to modify the Arduino sketch so that it only searches angles near the last best angle.