Display/Projection Project

Hello everyone,

I am looking to create a "projector" that can be mounted on top of a white/black board to project a grid or lines onto the board. The basic idea is this:

A professor can attach the device to the top of the board. The device is switched on, and funnels high intensity light/laser through a series of optics that distort the light and make it appear on the black/white board as a grid or lines. The purpose of this is to be able to have non-permanent lines/grid on the board while teaching.

I've considered using actual projection technology, such as DMD or DLP, but those seem exorbitantly expensive and difficult to program. I've also considered an LCD screen that can be controlled by the Arduino, with lines shown on the screen, and projected onto the board.

I was thinking something as simple as getting a strong laser/high intensity light, and passing it through 2 filters: 1 to create lines, 1 to create a grid. There will also be clever optics involved, to decide the line scale/focal point of the projector.

Are there any "projector" options for Arduino/Raspberry pi? Is it even strong enough to sustain a high intensity laser/light for several hours? What would be the highest intensity light that an Arduino can support? I am planning to use the ATMega 2560, and have experience in Assembly/C/Arduino coding.

Thank you,


Not so long ago I saw laser devices to project a line on a wall - in that case as horizontal line for renovation works, to get the tiles done. No microcontroller involved, just a line. The thing had to be be set horizontal manually even :slight_smile:

Look into laser devices that can be controlled through a microcontroller, and of course make sure that device won't overheat when you use it for long time (they shouldn't but with cheap Made-in-China ones you never know).

Why is there an Arduino?

Have you seen those Christmas lights which project stars or rainbows onto the outside wall of your house? They were very popular here last Christmas. They have a single laser which shines through a lens which splits the laser into a grid of dots. Grab one of those lenses and I'm sure you can make a projector to show a grid very cheaply.

Hi Arthur,

Use 2 diode lasers of maybe 5 or 10 milliwatts. put them next to each other, and pass each laser through a cylindrical lens and a diffraction grating - one for the horizontal lines, and one for the vertical lines. The gratings and lens will provide the spread, so you will need to experiment for where the ideal location is. Like everyone else, I can't see an obvious Arduino connection.

ps, an Arduino does not have anything to do with how much power is projected by a laser or other peripheral device. They all have their own power supply.

Thank you, everyone! There really is no obvious Arduino connection; this is simply the only computer hardware I'm familiar with, and I thought I would start here...I thought I'd actually need to project an "image" of some sort. However, the Christmas light idea is an excellent one! I suppose the Arduino will only be used to turn the device on/off, while the device will be powered and focused separately.

Thank you for your responses! I was overthinking this to begin with.