Re: Barcodes & error detection

"Brian Davis" <[email protected]> wrote in message 
news:[email protected]...
> In lugnet.robotics, Philippe Hurbain wrote:
>
>> Error correction is good, but no error
>> is probably better...
>
>   Absolutely, but in any real world application there is almost always 
> some
> error rate.

I'm just curious, but how much development did you do making the area where 
the light sensors themselves are mounted as black and light-proofed as 
possible to make sure you didn't get a problem from stray lightsources 
interfering?  If it's only happening on every 16th trip, maybe there's an 
intermittent light source that is tripping it up somewhere or perhaps 
occasional movements of parts flick a spot of light in at the wrong time.

It would in any case be interesting to see just how much light variation it 
can handle on it's own and still read accurately.  If you have some fairly 
clear close-up photos of the sensor and lighting assembly, perhaps you could 
post them somewhere.

Have you thought about making some track correction routines that can use 
the light readings so as to correct it's own errors while driving around - 
I'd have thought that any programmable bot ought to be able to spot when an 
error is coming up to unacceptable tolerances and try a course correction 
routine to negate or minimise the error.  In fact most good line follower 
bots should be able to navigate any strip and be accurate all the time, as 
it's mostly a matter of making sure it's properly detecting light vs dark 
areas.