Robot navigating by visible light alone
@ August 21, 2008
Update:
To make FritsLDR stand the ultimate test, I wanted it to navigate with light only.. but using a standard old fashionable light bulb instead of a smart & fast display of super bright LED's to track in front..
.. and then it had to navigate at a kitchen table.. where all lights in the cieling was florescent lamps :)
And it can be done. Quite easily actually! So this concludes this for me; It CAN be done - you can navigate by visible light, and you can make your own sensors with just some source of light and a cheap LDR!
I may upload some code for the filtering of florescent light if I have time or someone asks. However, it is very easy to do; Look at the "how to", use the code attached. Instead of "Pause P", use the time to measure perhaps 4 times, and let this be the result that you subtract from the other result (light on / off) and get difference from these two averaged variables instead. That does the trick.FYI; In the video with the light bulb, I am reading 40 times on / 40 times off, and get the average.. But that is because I have to spend the time it takes the darn thing to start glowing on something :D
You may not think much of it, but to me it is sensational :D
The worlds first robot navigating by the reflection of visible light - does not care if it is driving in day or night, artificial or natural light :)
(And yes, it is also a Joystick)
Instructions on how is found here: http://letsmakerobots.com/node/1833
@ Thu, 2011-08-11 23:11
I can say, I am more
I can say, I am more impressed with this method than using the other methods. mainly because it is "ingenuity to solve the problem and isn't just throwing money at it". I prefer to use found things and scrap over buying ready made devices. I know there is technology to do it available but whats in the junk to do it equaly well? besides it guarentees being one of a kind and there is nobody else to credit. Else why not just purchase a kit.
for me it is just that, "the challenge of using scrap and recycle componants". aside from the micro cntroler and servos, but I am also learning to do that part. too.
@ Mon, 2009-12-28 12:19
Creative and cheap
You can teach an old dog new tricks. Cad sulfide photo resistors have been around for decades and dirt cheap (free if you know how to recycle old electronics). LEDs are now dirt cheap too. I learned from old school, usually liked the comparator on off ajustment system. You just gave me ideas for some future R&D (better dust off the scope). I have mabe 5 colors of LEDs laying around and a few photo resistors. A little rusty on the spectrum range of the photocells. Silicon solar cells can also be used in a similar way, but much bigger in area. I am always a sucker for creative electronics. I have been expermenting with frezno type flat lenses and bright LEDs for indoor lighting. I don't know if it can be applied to robotic eyes though.
@ Sun, 2009-12-27 07:22
body
@ Thu, 2009-05-14 21:32
Colour the Future
Well impressed with the "Visible-Light" ideas.
Bots are plain boring with IR light (you cant even tell if they are switched on or not)
So i say "Vote For Visible Light" and Light up your path so people can see you - the more Colours and the Brighter the better.
(Cool "Retro" Joystick :-)
@ Thu, 2009-05-14 13:31
Lol, well thats why they use
@ Mon, 2008-10-20 19:00
Haha
@ Fri, 2008-08-22 08:50
Ehi it definitely seems to
@ Fri, 2008-08-22 09:03
Yes and no:NO:If you like
Yes and no:
NO:
If you like to program in a way that you know excactly (measured in human-distance like CM's) how far away things are.
YES:
If you like to program a robot that has a very "subjective" measuring to distance; You know when something is close, but if it is further away you may not see it, or just know that it is out there. (Like a person driving a car; distance can only be relyed on when the objects are really close - else it is quite subjective)
NO:
If you are just using one LED and a small LDR. This is what I do on this bot (so far) and this can only be used at a distance of some 5 CM.
YES:
If you are using multiple and powerfull LED's, specially the red ones, and the biggest LDR(s) you can find. That way you can make it react to objects up to 30 CM away (as far as I have made it, but that was actually before I made some optimazation in the code that has proved to make much better results, so it may be that even my setup can look further) Indoor is of course best, some 30% off distance in bright sunlight outside.
- I am going to make one that navigates this way myself :)
@ Fri, 2008-08-22 14:24
Ok, i think that anyway we
@ Fri, 2008-08-22 14:49
It IS more crap! But is is
It IS more crap! But is is also more fun :)
And some of the crap can be usefull - like the ability to select colors and be a lot better than avarage IR's to line following.
I'd say that it is betwenn standard little things you use to line sensoring (Emitor colector in black plastic), and SHARP IR finder.. But is just looks so much more COOL :D Colors flashing :D