'Laser Grid' Project

Hi There,

Been looking around for the last few months, and doing a hell of alot of research. Im planning a project where by:
There will be (for example) 16 by 8 laser diode's with photocell sensors at the end of them. Hopefully when I put my finger in to break the light, data will spit out.
Im planning on using Reaktor to turn the data into a sequencer and instrument of some sort.
My question is, can anyone point me in the right direction with some tutorials? Im planning on having at least 30 sensors, can the arduino handle this amount of inputs?

Thanks in advance.

for sound output I know that you can interface with GarageBand. I have only used it with mac.

Im not planning on using sound output, but using MIDI or OSC to interact with Reaktor.

Im planning on having at least 30 sensors, can the arduino handle this amount of inputs?

Not directly.

If you are looking for simple "on/off" digitial detection (ie, laser blocked or not), then something like a cascaded series of 595 shift registers or a "Centipede Shield" can easily provide you with enough I/O to do what your want.

If you are looking to sense changing levels of light of all 30 detectors, then the complexity will go up, but it still should be doable (maybe via matrix switching to the 6 analog I/O lines on the ATMega).

You might have an easier time, though, using a Arduino Mega or something similar...

It will simply be an on/off system. So do you recommend using the ATMega?
Where is the centipede sheilf available to buy?
With this type of project, will it simply be attaching the sensors directly to the board?
Thanks very much.

Centipede Shield

It will simply be an on/off system. So do you recommend using the ATMega?

Only if you haven't bought any hardware, yet - if you already have the Arduino 2009, then going with a shift register or centipede shield would probably be a better idea - unless you think your software will end up being larger than what your Arduino can support.

Where is the centipede sheilf available to buy?

I see that someone has already answered this...

With this type of project, will it simply be attaching the sensors directly to the board?

Sorta - you might need a resistor or such for pull-down reasons, but more or less, yes. You might also need to build a driver circuit for the lasers to turn them on and off (unless it will be a manual thing with a switch), but that is fairly simple to do.

One thing you will have to look for is to match your phototransistors to the laser's wavelength; some phototransistors have a wide bandwidth they can sense (visible light to IR), some are only sensitive in a narrower band (typically the IR region). So try to find spec sheets on the phototransistors before you decide and buy...

:slight_smile: