Society of Robots - Robot Forum
General Misc => Misc => Topic started by: MaltiK on November 12, 2008, 05:05:36 AM
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Is this possible to use a LDR on one microcontroller and a laser on another and when the laser hits the LDR 1's appear, and when it doesnt, 0's appear, does anyone know of a tutorial for this, its a very interesting subject.
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I've done a project like this some years ago. But I transmitted analog signals instead of digital :o
It's pretty easy really. What I did before was I connect a laser pointer to the audio-out of a radio, and an LDR to the audio-in of an amplifier. I can't really remember the exact circuitry, but it was probably just some transistors for a bit of amplification etc.
This setting worked perfectly indoors. The furtherst I tested indoors was like 5 metres, and there was very little noise.
I tried to do it outdoors during a party we had, but the laser beam was too small to see from a few metres. I had a really hard time trying to focus the beam exactly on the LDR. Since a party is not a party without music, I had to cancel my experimentation after a few minutes of trying :(
I remembered seeing some tutorials on the web. There was this guy who managed to get his system working across the street. But he used a really big laser.
Google around!
Found this: http://www.instructables.com/id/Send-Music-over-a-Laser-Beam/
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Sweet project man. How long did it take you to write the interface for it (translating data to laser and then back to data again)?
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there is no software involved with the laser music system , its all in the circuitry
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When I was in high school, I saw a LASER data transmission project. If you can imagine this, on the transmission side, the guy glued a piece of cardboard to a speaker cone on edge so that the cardboard stuck out perpendicular to the speaker cone. The speaker/cardboard were positioned so that it blocked the LASER beam when the speaker coil was not energized and unblocked it when the speaker coil was energized. He would send a "high-speed" data stream through the speaker. The receiver on the other end would then reproduce the data stream.
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check these projects:
http://ronja.twibright.com/
http://www.modulatedlight.org/
they give a decent intro on the subject.
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Its actually really easy . . . hook up the outputs/inputs to the Tx and Rx of your mcu UART, and you're done :P
If you have a $50 Robot completed and a pocket laser handy, I bet you can get it working in under 2 hours (including any soldering).
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Its actually really easy . . . hook up the outputs/inputs to the Tx and Rx of your mcu UART, and you're done :P
If you have a $50 Robot completed and a pocket laser handy, I bet you can get it working in under 2 hours (including any soldering).
So, using the Laser as a transmitter, what do you use as a reciever, and LDR?
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So, using the Laser as a transmitter, what do you use as a reciever, and LDR?
Depends on the wavelength of the laser :P
Unfortunately an LDR is too slow for a receiver, as it takes up to ~10 ms to change resistance. I *think* the pen lasers also emit infrared but not sure. Try using an infrared LED receiver and see if you get a signal - LEDs take only microseconds to detect a signal.