Introduction: Lighthouse Circuit Sculpture

About: I like to make stuff, and I am always thinking of new ideas.

This lighthouse-shaped circuit sculpture charges during the day with a pair of solar panels, then blinks at night.

It is controlled by an ATtiny85 that wakes up every few seconds to check the amount of light, then goes back to sleep again to save energy. At night, the circuit detects less light (less energy from the solar panels) and starts a flashing sequence.

(The solar panels are on the back, facing out the window).


  • Copper wire (18-20 gauge, uncoated)
  • 2 solar panels (2-3 volts)
  • 1F 5.5v Capacitor
  • 200k ohm resistor (or 2 100k ohm resistors)
  • 10k ohm resistor
  • 1k ohm resistor
  • A diode
  • An LED (red uses the least amount of energy)
  • 1 ATtiny85 chip

Step 1: Programming

Upload the provided code to your ATtiny85 (or similar microcontroller).

In order to upload the code, you will either need a special programmer or you will need to set up an Arduino Uno to upload the code. Just look up "Programming ATtiny85 with an arduino".

Step 2: Breadboard-ing

Build the circuit on a breadboard to prototype it. Once it works, you are able to start soldering!

Step 3: Attach the Solar Panels

Solder the solar panels onto the back of the frame. The solar panels are connected in series, so the positive (+) of the first panel connects to the negative (-) of the second panel. The negative (-) of the first panel connects to the frame (ground). See the image for more details.

Step 4: Build the Circuit

Construct the rest of the circuit. You may find it helpful to set everything on top of a piece of perfboard to hold everything while you are soldering. I left the bottom of the pins open so that I can re-program the ATtiny if I need to. After you are done, attach the circuit to the solar panels and add the rest of the frame around the circuit.

Step 5: Add Finishing Details

Add some finishing details, such as a small roof cap over the light, or a door at the bottom.

Step 6: Display It!

Put your circuit somewhere where it can charge during the day (with the solar panels on the back) and flash at night. A windowsill is a great place because the solar panels on the back can charge during the day and it is visible from inside and outside. The light on the top will start fading at approximately 8 second intervals in the dark (the flashing intervals can be changed in the code if wanted).

Thanks for checking out my Instructable! If you liked this project, please consider voting for me in the Sculpt and Carve Challenge.

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