Post by Dingo on Nov 10, 2006 10:45:43 GMT 10
Ok my problem is I want very precise motion tracking of how far my bot moves (don't we all? 
)
Having pondered this for a while nothing seemed to be accurate enough for a small bot.
Then I thought, what if one could use the guts of a PC mouse to track even the slightest change in movement? So I started researching it.....
Obviously the first question is Optical or Ball.
I'm tending to think Optical for the following reasons:
*Dirt will clog a ball pretty quickly
*Ball + associated assembly is rather large to implement on a small bot
*Balls require a modest amount of pressure to push on the sensing rollers.
One major issue with an Optical mouse is that it doesn't work on all surfaces.
The advantage of optical is that doesn't actually need to touch the surface (although standard mice lens need it to be very close)
It seems most Optical mice use this cp.literature.agilent.com/litweb/pdf/5988-9774EN.pdf or a similar component.
Basically it is 18x18 CCD camera with built in circuitry to track changes between frames and outputs it all on a serial port. Sounds about perfect for small bots.
A basic article using it as a scanner is here www.spritesmods.com/?art=mouseeye
A really good in depth article about how to change the lens so it doesn't have to be so close the surface and other interesting solutions to using these sensors in robots can be found here "http://home.comcast.net/%7Emaccody/robotics/croms-1/croms-1.html"
So anyway, I'm off to buy a cheap optical house to hack and lets see what results can be achieved
)Having pondered this for a while nothing seemed to be accurate enough for a small bot.
Then I thought, what if one could use the guts of a PC mouse to track even the slightest change in movement? So I started researching it.....
Obviously the first question is Optical or Ball.
I'm tending to think Optical for the following reasons:
*Dirt will clog a ball pretty quickly
*Ball + associated assembly is rather large to implement on a small bot
*Balls require a modest amount of pressure to push on the sensing rollers.
One major issue with an Optical mouse is that it doesn't work on all surfaces.
The advantage of optical is that doesn't actually need to touch the surface (although standard mice lens need it to be very close)
It seems most Optical mice use this cp.literature.agilent.com/litweb/pdf/5988-9774EN.pdf or a similar component.
Basically it is 18x18 CCD camera with built in circuitry to track changes between frames and outputs it all on a serial port. Sounds about perfect for small bots.
A basic article using it as a scanner is here www.spritesmods.com/?art=mouseeye
A really good in depth article about how to change the lens so it doesn't have to be so close the surface and other interesting solutions to using these sensors in robots can be found here "http://home.comcast.net/%7Emaccody/robotics/croms-1/croms-1.html"
So anyway, I'm off to buy a cheap optical house to hack and lets see what results can be achieved
