Solar Powered Light-Graffiti Projector




Introduction: Solar Powered Light-Graffiti Projector

I recently read this interesting article in Wired magazine about "Light-Graffiti Hackers". The Problem with light-graffities is that you need a power source to make them permanent, so you usually can't put them everywhere you like. So I thought about making a small solar powered Light-Graffiti Projector that can be mounted nearly everywhere. The problem is that it mustn't be very expensive in case it gets stolen, confiscated or whatever. First I thought about using a cheap laser pointer as a projector source, but you can't make these caps to display different symbol by yourself. They are called "Holographic Optical Elements" and they are very expensive in production if you only need one with your special image (tell me if you know how to make them by your own). So I decided to use a LED. I also noticed that solar panels are still very expensive, but then I found one of these solar powered garden lights for only 5 Euros and transformed it into a "Solar Powered Light-Graffiti Projector".

Step 1: This Is What You Need

One solar powered garden lamp for about 5 Euros. Found mine at the German electronics supply store "Conrad". One optic lens to focus the projected image. One ultra bright LED, the one in the garden light is usually to dim. I took a red one. Two small pipes of aluminium or plastics, each about 5 cm in length, that fit into another. The outer tube should have the same radius as the lens.
The image you want to project on the wall, printed on a transparency film. You should print it with a high resolution because the image is magnified.

Step 2: Disassemble Garden Lamp

First of all you have to remove everything except the top of the garden light which houses the solar panel and the LED. After this replace the LED with the brighter one.

Step 3: Add Smaller Tube

Now take some hot glue and mount the LED at one end of the smaller tube. On the other end you have to attach the transparency film.

Step 4: Mount Bigger Tube

Finally slide the bigger tube on the smaller one and attach the lens on the bigger tube with some glue. If you like you can attach a stand like a tripod, as I did. You also should put some hot glue on all holes to make your projector weatherproof.

Step 5: Final Projector

Now you only need to find a place where you can put it. You should carefully choose a place with a lot of sunlight. The advantage of the used solar garden light is that it only lights up at night when the graffiti can be seen. I've tested mine on the balcony the last days but I have to say that the sun here in winter is too weak to give the energy for a whole night of projection. Perhaps I should wait till spring until I expose my projector to the street. So watch out, perhaps you will see one of these someday in Munich.



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    103 Discussions

    Oh man, you should be in GRL... I love this!

    That's a really good idea. I have to ask though. Does the solar panel have to face the sun directly for it to be efficient??

    8 replies

    shadow07, I havent experimented with these small panels much though I do have some solar walkway lights (currently buried underneath the snow = not very effective). From what I have read about solar water heating panels, and should be true for all solar panels, is generally facing your panel south and with a little bit of tip toward the south (instead of the panel looking straight up) you are going to get just about the same results (within 10%) of getting a solar contractor to come out to your house and align it for the 100% best angle.

    thanks. good catch. I guess I was thinking too locally. these here "internets" are kind of a big deal ALL OVER the world, huh? ; )

    yeh can't blame you for forgetting. i don't seem to be able to get the lens. so none of this information is helpful to the southern hemisphere. but thats no fault of the people here, its the damn lack of people in Australia and lack of demand for a simple convex glass lens.

    Go to any pharmacy and look at the 'readers' bifocals glasses...would any of them do the job? Can you not shop on the ubiquitous Internet?

    I didn't have the chance to test it, but I think a clear sky would be sufficient. I often see these lights in the neigborhood and they are very dim in winter. I would suggest aiming for a better solar panel.

    they work fine as garden lights not pointed directly at the sun, i don't see why the changes would make them work any different.

    the doods name irl is prob rodney.... now shorten it rdni or rdn1.. thats my guess

    grab one of those cheap LCD alarm clocks and remove the back layer of the LCD and put it in the tube and, DIY PROJECTOR ALARM CLOCK! get it?