Let's Make Robots!

PeteH's blog

Question - Rev counter

For this project here http://letsmakerobots.com/node/22474, I am needing a simple sensor to indicate the number of revolutions a tsecond that an axle makes.  However this will be in a dirty/oily place (under isde of carriage bogie) so I am wondering on the best method of sensor to use.  I think I have narrowed it down to three possibilites -

1/ Optical slot interupter with seperate encoding wheel.  Probably easiest option but how prone to dirt and mis reading.  Could be hard to clean.

Printable Arduino manual with ALL commands

Well I now have received my first arduino (duemilanova), having used PICAXEs for a few years,  but have a problem.

I do not have internet at home, where I do the programming, and cannot find a printable version of the arduino language manual (if there is one!).  I download a couple of basic 'beginners' manuals and printed them off, as well as the extended language reference.  My main problem comes in that some of the examples seem to be using commands not in the extended reference.