Arduino Heliostat Calculates The Position Of The Sun

We’re past the winter solstice and the days are getting longer, but that doesn’t mean we’re not sick of the sun setting around 5 in the afternoon. There is a way to get more sunlight through our windows – a heliostat. Lucky for us, [Gabriel] sent in his Open Source Sun Tracking / Heliostat project that can reflect sunlight through our windows all winter long.

Using mirrors to brighten up a room is an ancient practice; a few thousand years ago, heliostats went by the archaic term, “slaves.” Luckily there’s a far more elegant way of doing things nowadays – an Arduino. [Gabriel] came up with an Arduino sketch that calculates the altitude and azimuth of the sun using only latitude, longitude and time zone. [Gabriel] used this sketch to drive a pair of stepper motors and reflect sunlight through his window.

You can check out [Gabriel]’s demo of his heliostat after the break.


14 thoughts on “Arduino Heliostat Calculates The Position Of The Sun

  1. The amount of natural light decrease in the late afternoon during Winter is noticeable in my home. I have often wonder if I could use mirrors to help out, but after seeing how this concentrates sunlight on interior surfaces, I’m not sure this is a solution I’m looking for. For a single story home the solatube might be more desirable and maybe at less cost. Not to say an open source heliostat project wouldn’t have utility in other applications.

  2. @name required
    Time is needed. So as you can see on the page, a RTC DS1307 is used in the project to keep up with the time.

    The Arduino is probably able to track the sun because of its relatively slow track across the sky, I wonder if it’s snappy enough to calculate satellite positions overhead. Tack on a GPS to get time/lat/long/altitude and it’d be nice to have a mobile satellite tracker (using pre-uploaded TLE files).

    Something along these lines:

  3. I’d love to see a few of these funneling light into some fiber optic based light tubey things so that you could get light into oddly-placed rooms or ones without windows.

  4. Awesome project!

    Add a few hundred more mirrors and BAM arduino death ray.

    I have a photovoltaic array on my roof. Thinking about extending my solar day with a heliostat array.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.