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Topic: DVD-Rom Drive Based LiDAR? (Read 843 times) previous topic - next topic

mightyaad

I want to make a cheap LiDAR as my Arduino project.
By cheap I mean low cost with reasonable performance.
I saw the famous WiiDAR http://myrobotlab.org/node/1
It made me think why not use the laser diode and optical component that a DVD-Rom Drive has in order to achieve the same goal?

Is it possible to use those components for making a LiDAR with Arduino?
https://upload.wikimedia.org/wikipedia/commons/f/f0/CD_laser_assembly1.jpg

mercury20101010

That's a great question. I'm also trying to build a simple lidar system with a dvd laser diode, a light sensor (resistor) a dvd tray extender motor and a 45 degree tilted mirror.

I plan on having the laser and sensor point downward from a fixed arm onto the mirror to have it bounce 90 degrees outward as it spins. Hopefully the sensor can give accurate readings of at least a foot increments.

The mirror is more than likely not level, so I don't know how that will effect it but as long as it's consistent I won't mind.

I'd like to see someone with experienc add to this question.
And please excuse me. I don't normally use forums so I and pretty much unaware of the proper etiquette in participating in forums.

Robin2

If this involves measuring the time between transmission and receipt of a light flash will a 16MHz Arduino be fast enough to measure the gap?

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

bobcousins

As a good rule of thumb, light travels about 30 cm (1 foot) per nano-second, equivalent to a clock speed of 1GHz.

You would need some specialized hardware to measure intervals at that resolution, an Arduino has no chance :(
Please don't PM me asking for help. Ask questions in the forum.

AWOL


If this involves measuring the time between transmission and receipt of a light flash will a 16MHz Arduino be fast enough to measure the gap?

...R

These devices typically use parallax/triangulation, hence the spinning mirror and the linear detector.
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Robin2


These devices typically use parallax/triangulation, hence the spinning mirror and the linear detector.


I don't know anything about that stuff. Does it mean a 16MHz Arduino is fast enough?

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

AWOL

I've seen a CCD / laser rangefinder/scanner using an old 33 1/3rd RPM turntable, so yes, a 16MHz Arduino is fast enough.
http://letsmakerobots.com/node/2651
"Pete, it's a fool looks for logic in the chambers of the human heart." Ulysses Everett McGill.
Do not send technical questions via personal messaging - they will be ignored.

Robin2


I've seen a CCD / laser rangefinder/scanner using an old 33 1/3rd RPM turntable, so yes, a 16MHz Arduino is fast enough.


Thanks for the link - very interesting.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

cr0sh

You could always try to improve upon this project:

http://letsmakerobots.com/node/2651

The hardware and concept is pretty basic, and can only measure the distance to a single point; the improvements would be to increase the distance (maybe a combo IR filter, as well as matching the phototransistor to the laser wavelength, perhaps a better amplifier - and/or maybe substituting a different kind of detector for the phototransistor - maybe a pin or avalanche photodiode perhaps - or maybe just a more sensitive photodiode or phototransistor), and make it scan in two dimensions (I thought about maybe panning the phototransistor while tracking the angle might be a good way).
I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

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