Hi, > I thought Ginger had a (small) gyroscope to determine orientation and > rotation and used that to control the motors that drive the wheels. I do not > thinnk it has a big flywheel for stability. Am I wrong? By what I have read it actually has 5 solid state gyros !! It can detect attitude changes in any direction. Should have been a nice control program to implement :-) Best regards, Alexandre Guimaraes -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu